JP2009160594A - Cast iron member for cast-in and manufacturing method thereof, and cylinder liner for cast-in - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a product with which in the case of cast-inserting with an aluminum alloy to a cylinder-liner, etc., in a cast iron-made internal combustion engine, etc., the stickiness at the mutual interfaces is more stabled with lower manufacturing cost, in comparison with the conventional product. <P>SOLUTION: The cast iron member for cast-in, is the cylindrical shaped cast iron member with roughly-made outer circumferential wall surface which provides a splayed coating roughened with a plurality of projected parts formed by sticking momentarily solidified molten droplet splash while colliding the molten droplet of molten metal on the outer circumferential wall face of the cylindrical cast iron member rotated at high speed in the circumferential direction. Then, the projecting parts are constituted by including needle-state, sponge-shaped and platy-shaped molten droplet splash. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cast iron member for casting, a manufacturing method thereof, and a cast iron product for casting.

  A cylinder block for an internal combustion engine of an automobile is a basic structure on which a cylinder in which a piston slides and other accessory devices are assembled. That is, since the cylinder block is a basic part of the engine, the cylinder block is required to have sufficient strength, rigidity, and vibration resistance, and the inner surface of the cylinder is required to have wear resistance. For this reason, cast iron cylinder blocks have been conventionally used, but in recent years, aluminum alloy cylinder blocks have been increasingly used. The reason is that the fuel consumption is improved by reducing the weight of the vehicle by reducing the weight of the engine.

  However, some problems arise when the cylinder block is made of an aluminum alloy. The cylinder block is a part of engine parts, and the engine is driven by burning gasoline, so that the cylinder block is exposed to high temperature due to combustion heat of fuel. Under such circumstances, as the temperature rises, the aluminum alloy has a characteristic that the mechanical strength decreases.

  Therefore, a cooling means for cooling the cylinder block is required. In the jacket portion where the cylinder block is in contact with the cooling water, the temperature rise of the aluminum matrix can be suppressed, but generally no cooling means is provided in the gap between the cylinders. This is because in order to make the overall length of the engine as compact as possible, it is necessary to shorten the separation distance between the cylinders, and there is no room for cooling water to flow. Therefore, the aluminum matrix located between the cylinders becomes a high temperature region due to the combustion heat of the fuel, and the strength as an aluminum material is partially reduced.

  Moreover, considering that the cylinder liner is cast with the molten aluminum alloy, in the solidification process of the molten aluminum alloy, the aluminum-based matrix between the cylinders is the portion where the residual stress is highest. When the residual stress in this part is released when the engine is started, separation occurs between the aluminum matrix located between the cylinders and the cylinder, resulting in loss of heat conduction and deformation in the shape of the cylinder bore. Therefore, it is not preferable because it causes a decrease in engine performance.

  Conventionally, in order to reinforce the bonding strength between the cylinder liner and the cylinder block, the outer peripheral wall surface of the cast iron cylinder liner is cast with an aluminum alloy or the like, which is the same material as the cylinder block, to form a metallic bond. I have been. However, in the case of a cylinder block made of an aluminum alloy, a cylinder liner (made of cast iron) made of a different material is contained inside the cylinder block, so that it is necessary to consider the joining state of the different material. For example, in the case of a cylinder block made of an aluminum alloy, there is a large difference between the melting point of cast iron products (about 1200 ° C.) and the melting point of aluminum alloy (about 700 ° C.). Therefore, mutual diffusion at both interfaces hardly occurs during casting, and from the viewpoint of diffusion bonding at the interface, it is difficult to improve the adhesion between the cylinder liner and the cylinder block. In addition, when the cylinder liner is cast, it must be assumed that gas is confined by the molten metal, a gap is generated between the cylinder liner and the cylinder block, and the bonding strength is reduced.

  If the adhesion at the interface between the aluminum alloy cylinder block and the cast iron cylinder liner is not maintained well, the thermal conductivity between the cylinder liner and the cylinder block body will decrease, and the engine cooling performance Cause a decline. In addition, the level of thermal expansion varies depending on the location of the cylinder liner, and there is a possibility that partial peeling at the interface occurs due to the influence of vibration, impact, etc. when the engine is driven. As a result, the performance and durability of the internal combustion engine are reduced.

  In response to such a problem, for example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-55956) proposes a cylinder block with a liner in which cylinder sleeve deformation is small, and oil consumption and piston hitting noise are reduced at low cost. Yes. Patent Document 1 includes a light alloy cylinder block main body and a cylinder sleeve made of a cast iron hollow cylindrical body provided as a liner on the inner surface of the main body, and an outer peripheral wall surface of the sleeve. Has been proposed in which grooves are formed so as to extend parallel to each other, and the side surfaces of the grooves are parallel to each other. And the said groove | channel is formed so that it may extend in the circumferential direction or axial direction of a hollow cylindrical body, and it is specified that the depth of this groove | channel is 0.5 mm or less.

  Further, Patent Document 2 (Japanese Patent Laid-Open No. 2001-170755) proposes a cast iron member for casting that is excellent in filling of an aluminum material and adhesion to the aluminum material when die-casting. In Patent Document 2, as a coating material, 20 to 45% by mass of silica sand having an average particle size of 0.05 to 0.5 mm, 10 to 30% by mass of silica flower having an average particle size of 0.1 mm or less, and a binder. The maximum height Ry of the surface roughness is 65 to 260 μm, and the average interval Sm between the irregularities is 0.6 to 1.5 mm. A cast iron member for casting having a casting surface has been proposed.

  Further, Patent Document 3 (Japanese Patent Laid-Open No. 2001-234806) proposes a cast-in product that improves the adhesion between the cast-in target part and the cast product. Patent Document 3 discloses a casting method for producing a cast product by casting a cast object part with molten metal, and is made of a metal material different from the metal material constituting the cast object part. In contrast to the casting target part having a coating made of a metal material having a melting point equal to or lower than the melting point of the molten metal, the coating is formed on the surface of the casting target part having a surface roughness of 1 to 20 μm Rz. A casting method has been proposed.

JP 2001-55956 A JP 2001-170755 A JP 2001-234806 A

  However, since the cast iron cylinder sleeve described in Patent Document 1 has a groove formed by machining on the outer peripheral wall surface thereof, the adhesion at the interface with the aluminum alloy material is improved when casted with an aluminum alloy or the like. However, the processing is very expensive and the cost of the product cannot be reduced. Certainly, if the high pressure die casting method is used, excellent adhesion can be obtained between the cylinder sleeve and the aluminum alloy material, but if the low pressure casting method is used, the bottom of the rugged shape of the cast iron member can be obtained during casting. Filling with molten metal may not be possible, and good adhesion is difficult to obtain. If good adhesion between the cylinder block and the cylinder liner cannot be obtained, the heat generated by the combustion of the fuel cannot be efficiently radiated, resulting in a problem of poor heat sinkability (heat dissipation).

  In addition, the cast iron member for casting described in Patent Document 2 has a cast surface of Ry 65 to 260 μm and Sm 0.6 to 1.5 mm formed on the outer peripheral wall surface by centrifugal casting. Adequate adhesion cannot be obtained with the aluminum alloy material. The reason for this is that the cast iron member for casting in Patent Document 2 uses a coating material at the time of casting, and countless fine indentations due to steam holes generated when drying with the heat of the mold are formed on the surface of the cast iron member. This is because it is formed. The cast iron member improves the adhesiveness with the aluminum alloy material by using the fine dent generated at the time of casting, but the molten metal cannot be filled to the bottom of the dent by low pressure casting. Because. As a result, the cast iron member has a problem that heat adhesion (heat dissipation) is poor because sufficient adhesion with the aluminum alloy material cannot be obtained.

  Further, in the cast-in product described in Patent Document 3, a coating made of a metal material having a melting point or lower of the molten metal used for the cast-in is formed on the outer peripheral wall surface of the product by thermal spraying or the like. Then, irregularities are formed on the formed film by a shot peening method, a shot blasting method, or the like to improve the adhesion with the aluminum alloy material during casting. However, in this method, the film to be formed is thin, and if the high-pressure die casting method is employed, there is a possibility that it will be poured into the molten metal, and a sufficient adhesion effect with the aluminum alloy material cannot be obtained. Further, the surface roughness (Rz) of the cast-in product is reduced to 1 μm to 20 μm, and there is a problem that a sufficient anchor effect cannot be obtained with the aluminum alloy material in low pressure casting.

  From the above, it is desired to further stabilize the adhesion at the interface between the cast iron material and the aluminum alloy material when the cylinder liner of a cast iron internal combustion engine is cast with an aluminum alloy or the like. In addition, it has been desired to reduce the manufacturing cost as compared with the prior art.

  Therefore, the present inventors have conceived that the above-mentioned problems can be achieved by adopting the cast-in cast iron member shown below. Hereinafter, the present invention will be described.

Cast iron member for casting: The cast iron member for casting according to the present invention is a cylindrical cast iron member having a rough outer peripheral wall surface, and the outer peripheral wall surface has a cylindrical shape that rotates at high speed in the circumferential direction. The outer peripheral wall surface of the cast iron member is provided with a sprayed coating roughened by a plurality of projections formed by adhering a droplet splash of molten metal that is collided and instantly solidified.

  And the said protrusion part of the cast iron member for casts concerning this invention is comprised including the droplet shape of needle shape, sponge shape, and plate shape.

  It is preferable that the protrusion of the cast iron member for casting according to the present invention has a height of 0.05 mm to 10 mm and an adhesion width of the droplet splash is 0.1 mm to 10 mm.

  The protrusion of the cast iron member for casting according to the present invention preferably has an adhesion length of the droplet splash of 0.05 mm to 40 mm.

  The projecting portion of the cast iron member for casting according to the present invention has an area ratio of a region to which the sprayed material adhering to the outer peripheral wall surface adheres when the outer peripheral wall surface area of the cylindrical cast iron member for casting is 100% by area. However, it is preferable that it is 30 area% or more of the said outer peripheral wall surface.

  The thermal spray coating of the cast iron member for casting according to the present invention is made of any material of iron or iron-based alloy, aluminum or aluminum-based alloy, copper or copper-based alloy, zinc or zinc-based alloy, tin or tin-based alloy. It is preferable to become.

  As the cast iron member constituting the cast iron member for casting according to the present invention, it is preferable to use one having a groove-like uneven shape formed on the outer peripheral wall surface thereof.

  As the cast iron member constituting the cast iron member for casting according to the present invention, it is preferable to use the outer peripheral wall surface roughened by blasting.

Cylinder liner according to the present invention: The cylinder liner according to the present invention uses a cylinder liner as the cast iron member in the cast iron member for casting, and instantaneously solidifies by causing molten metal droplets to collide with the outer peripheral wall surface. A thermal spray coating roughened by a plurality of protrusions formed by adhering a droplet splash is provided.

Method for producing cast iron member for cast case: The method for producing cast iron member for cast case according to the present invention is a method for producing the cast iron member for cast case described above, which is supported by rotating the cast iron member having a cylindrical shape. A plurality of droplets formed by causing a droplet of molten metal to collide with the outer peripheral wall surface of a cast iron member rotating at a high speed in the circumferential direction at a speed of 30 m / min to 630 m / min, and causing a molten metal droplet to collide using a thermal spraying device. The thermal spray coating roughened by the protrusions is formed on the outer peripheral wall surface of the cast iron member.

  In the method for producing a cast iron member for casting according to the present invention, an arc spraying device is preferably used as the spraying device.

  In the method for producing a cast iron member for cast-in according to the present invention, the molten metal droplets are preferably injected at an air pressure of 20 PSI to 70 PSI of a thermal spray gun as the thermal spraying device.

  In the method for producing a cast iron member for casting according to the present invention, the molten metal may be any of iron or iron-based alloy, aluminum or aluminum-based alloy, copper or copper-based alloy, zinc or zinc-based alloy, tin or tin-based alloy. It is preferable to use such a material.

  The cast iron member for cast according to the present invention is a cast iron member for cylindrical cast iron having a rough outer peripheral wall surface, and the outer peripheral wall surface is on the outer peripheral wall surface of the cylindrical cast iron member rotating at high speed in the circumferential direction. , Which is obtained by forming a sprayed coating roughened by a plurality of protrusions formed by impinging molten metal droplets and adhering instantly solidified droplet splash, The roughening form completely different from the roughening treatment form is provided. The roughened surface can form an uneven surface with extremely large protrusions that cannot be measured by a normal surface roughness meter, and the protrusions themselves have a certain gap. Therefore, the wettability with the matrix material used for casting is excellent, and the adhesion at the interface is very good.

  Therefore, when the technical concept of the cast iron member for casting according to the present invention is applied to a cylinder liner and applied to the manufacture of a cylinder block using an aluminum alloy as a matrix material, there is sufficient unevenness on the surface of the cylinder liner. The sprayed coating improves the wettability with the molten aluminum alloy, making it easy for the molten aluminum alloy to enter the protrusions of the sprayed coating on the cylinder liner, and anchoring at the interface between the matrix and the sprayed coating on the cylinder liner. Is fully demonstrated. As a result, even if the low-pressure casting method is used, the adhesion between the cast iron member and the aluminum matrix is improved as in the case of using the high-pressure casting method. Therefore, it is not always necessary to form grooves and irregularities in the cast iron member in advance.

  The cast iron member manufacturing method according to the present invention includes a cylindrical cast iron member that is pivotally supported and melted by a thermal spraying method on the outer peripheral wall surface of the cast iron member while rotating at high speed in the circumferential direction. It is characterized in that metal droplets collide at high speed. Therefore, it is possible to use a conventional apparatus for forming a sprayed coating on a cylindrical cast iron member as it is, and it does not require new equipment investment, so it does not cause an increase in product cost and can be introduced very easily. It is a simple manufacturing method.

  Below, each form of the cast iron member for casting according to this invention, the manufacturing method of the cast iron member for casting, and the cast iron product for casting is demonstrated.

Form of cast iron member for casting according to the present invention: The cast iron member for casting according to the present invention is characterized by a roughening treatment form formed on the outer peripheral wall surface of the cast iron member for casting. The roughened surface of the cast iron member 1 with a thermal spray coating according to the present invention is observed with a microscope (magnification: x3 times to x100 times) as shown in FIGS. And in FIG. 4, the observation image of the narrow area | region which observed the thermal spray coating of the cast iron member 1 with a thermal spray coating concerning this invention with the scanning electron microscope is shown. As can be understood from FIGS. 1 to 4, it is difficult to accurately express this form as a word or to define it as a numerical parameter at this stage. Therefore, the applicants of the present application have formed the spray coating form as follows: “The molten metal droplet collides with the outer peripheral wall surface of the cylindrical cast iron member that rotates at a high speed in the circumferential direction, and the droplet splash that is instantly solidified adheres to it. The thermal spray coating is roughened by a plurality of protrusions.

  The protrusions of the cast iron member for casting according to the present invention are configured to include a droplet splash shape such as a needle shape, a sponge shape, and a plate shape. The thermal spray coating of the cast iron member for cast according to the present invention is formed by a thermal spraying method while rotating the cast iron member at a high speed, and the molten metal droplets injected from the thermal spraying apparatus are splashed by the collision of the molten droplets, Due to the influence of the centrifugal force of the cast iron member, it instantly solidifies and adheres to the surface of the cast iron member, resulting in a unique and irregular shaped protrusion. Therefore, the shape of the projections varies depending on the conditions during spraying (the number of revolutions of the cast iron member, the sprayed material, etc.). However, judging from the observation results of a microscope or the like, needle-like, sponge-like, and plate-like shapes can be judged as the main attachment forms. The protrusion formed by combining these unique shapes is formed by the droplet collision during spraying and the centrifugal force of the cast iron member, and thus is not greatly affected by the surface shape of the outer peripheral wall surface of the cast iron member. Therefore, in order to improve the adhesion between the cast iron member for cast-in and the aluminum matrix, it is necessary to form grooves on the outer peripheral wall surface of the cast iron member in advance or to form irregularities on the outer peripheral wall surface of the cast iron member by blasting. Absent.

  However, if the state of the roughened surface is deliberately expressed, it must be specified by the following parameters. First, it is preferable that the protrusions of the cast iron member for cast according to the present invention have a height of 0.05 mm to 10 mm. Here, “projection height” refers to the height H of the projection shape 20 on the surface of the cast iron member 2 as a mountain shape, as shown in FIG. When the projection height H is less than 0.05 mm, when the cast-in process is performed with an aluminum matrix, a sufficient anchor effect cannot be exerted, and the adhesion between the cast-in cast iron member and the aluminum matrix is low. It is not preferable because it becomes insufficient. On the other hand, when the projection height H exceeds 10 mm, when casting the cylinder liner with the aluminum material matrix, the gas tends to be trapped in the shape of the projection 20 due to the solidification of the molten aluminum alloy, and the casting A gap filled with gas tends to occur between the cast iron member for use and the aluminum-based matrix, and it becomes a delamination occurrence place at the time of temperature rise, which is not preferable because the joint strength of both is lowered.

  And as for the said projection part of the cast iron member for casts concerning this invention, it is preferable that the adhesion width | variety of the said droplet splash is 0.1 mm-10 mm. Here, as can be understood from the bottom view of FIG. 5, the “adhesion width” is a droplet splash that is blown up by air and centrifugal force on the surface of a cylindrical cast iron member and instantaneously solidified. The length W in the minor axis width direction when connected in a shape. Here, when the adhesion width W is less than 0.1 mm, the thickness in the width direction of the projection is reduced and the strength of the projection is reduced. Adhesiveness between the wrapping cast iron member and the aluminum matrix is insufficient, which is not preferable. On the other hand, when the adhesion width W exceeds 10 mm, it is a case where the droplet splash is unevenly adhered to the cast iron member for casting according to the present invention. That is, if the width of the protrusion is too large, uniform adhesion cannot be obtained, and quality variation as a roughened surface increases, which is not preferable.

  Furthermore, it is preferable that the protrusion of the cast iron member for cast according to the present invention has an adhesion length of the droplet splash of 0.05 mm to 40 mm. Here, as can be understood from the bottom view of FIG. 5, the “adhesion length” is a droplet splash that is blown up by air and centrifugal force on the surface of a cylindrical cast iron member and instantaneously solidified, or The maximum length L when connected in a mountain range. Moreover, this maximum length L is synonymous with the diameter of the circumscribed circle when the circumscribed circle C shown in FIG. 5 is assumed with respect to the area of the area where the protrusion is attached to the cast iron member surface. In addition, the adhesion form of this droplet does not always show the same form as illustrated in FIG. 5, and shows various forms such as a V shape and a curved type as the adhesion form when observed from the upper surface, It should be clearly stated that the concept of the circumscribed circle C can be applied to these. Moreover, the shape direction of a projection part can also be formed in the direction other than the circumferential direction by scattering by spraying conditions. Here, when the adhesion length L is less than 0.05 mm, the adhesion when cast is lowered, which is not preferable. On the other hand, when the adhesion length L exceeds 40 mm, the hot-water flow at the time of casting with an aluminum alloy is deteriorated, and the adhesion is deteriorated.

  Next, in the cast iron member for casting according to the present invention, how much the protrusions are formed on the surface of the cast iron member will be described. Here, when the outer peripheral wall surface area of the cylindrical cast iron member to be roughened is 100% by area, the area ratio of the sprayed region adhered to the outer peripheral wall surface is 30% by area of the outer peripheral wall surface. It is preferable that it is above (30 area%-100 area%). Here, when the exclusive area of the site | part provided with the said protrusion part is less than 30%, it is because the effect which improves the adhesiveness of the said cast iron member for cast-ins and an aluminum-type matrix is not acquired notably.

  In the cast iron member for casting according to the present invention, the thermal spray coating provided with the protrusions described above is iron or iron-based alloy, aluminum or aluminum-based alloy, copper or copper-based alloy, zinc or zinc-based alloy, tin Alternatively, any material of a tin-based alloy is preferably provided. The materials described here are relatively easy to cause an anchor effect and mutual diffusion at the interface with the aluminum matrix in the process of solidification of the molten aluminum alloy at the time of casting. As a result, a strong anchor effect and a metal bonded state are formed between the sprayed coating of the cast iron member for casting and the aluminum matrix, and as a result, the adhesion between the cast iron member for casting and the aluminum matrix is improved. Moreover, the cast iron member for cast-in with a sprayed coating formed of the above material has a roughened surface with the above-mentioned protrusions on its surface, but is excellent in wettability with the molten aluminum alloy during casting. The molten metal can be sufficiently filled up to the bottom of the roughened surface of the roughening treatment.

  The cast iron member for casting according to the present invention described above does not need to be preliminarily roughened on the surface of a cylindrical cast iron member as a production raw material. However, the cast iron member has a groove-like uneven shape formed on its outer peripheral wall surface, a surface roughened by blasting on its outer peripheral wall surface, or a groove-like uneven shape formed on its outer peripheral wall surface and blasted. You may use what was used together. This is because better adhesion between the cast iron member for casting and the aluminum matrix can be obtained. Here, the blasting process referred to here is a process in which a shot made of an abrasive material is sprayed onto the casting by applying a pressure by pneumatic pressure or centrifugal force, and the casting surface is roughened or reformed.

  Moreover, the cast iron member for casting according to the present invention can obtain good adhesion to the aluminum matrix even when using either the low pressure casting method or the high pressure casting method for casting. This is because the thermal spray coating has a unique structure, so that the molten metal can easily penetrate into the thermal spray coating even in low-pressure casting. The low-pressure casting method referred to here is a casting method in which a molten aluminum alloy material melted in a closed melting furnace is injected into a mold by applying a pressure slightly higher than atmospheric pressure. Apply a pressure of 1 MPa or less to push the molten metal up to the mold. In addition, the high-pressure casting method referred to here may be referred to as a high-pressure die casting method, in which a cast iron member for casting is placed in a die cast mold, and the die cast die and the cast iron member for casting are formed. This is a casting method in which a molten aluminum material is injected into a cavity formed therebetween at a high pressure of 490 MPa to 980 MPa, cooled and solidified, and a cast iron member for casting is cast in an aluminum matrix and integrated.

Manufacturing method of cast iron member for cast case: The method for manufacturing a cast iron member for cast case according to the present invention is a method for manufacturing the cast iron member for cast case described above, in which the cylindrical cast iron member is pivotally supported and rotated. A plurality of droplets formed by causing a droplet of molten metal to collide with the outer peripheral wall surface of a cast iron member rotating at a high speed in the circumferential direction at a speed of 30 m / min to 630 m / min, and causing a molten metal droplet to collide using a thermal spraying device. The thermal spray coating roughened by the protrusions is formed on the outer peripheral wall surface of the cast iron member.

  The rotation with the cylindrical cast iron member pivotally supported will be described. The cast iron member rotates at high speed along the circumferential direction at a rotational speed of 30 m / min to 630 m / min through the support shaft of the jig in the cylinder of the cylindrical cast iron member in synchronization with the rotation of the support shaft. Here, when the rotational speed of the cast iron member is less than 30 m / min, it is difficult to form a necessary protrusion shape on the outer peripheral wall surface of the cast iron member, which is not preferable. On the other hand, when the rotational speed of the cast iron member exceeds 630 m / min, the rotational speed becomes excessive and more droplets are scattered without adhering to the surface of the cast iron member. In order to form the projection height, a large amount of thermal spray material and time are required, and the use efficiency of the thermal spray raw material is reduced, which is not preferable. As a more preferable range, the rotational speed of the cast iron member is in the range of 50 m / min to 480 m / min.

  There is no particular limitation on the thermal spraying apparatus used here. However, from an economic viewpoint such as cost and mass production stability, it is preferable to use an arc spraying apparatus as the spraying apparatus. Briefly describing the arc spraying apparatus, it is a method in which a direct current is passed through two wires, which are sprayed materials, arced and melted, atomized with air or other gas, and attached to the base material. It is possible to form a rough coating or to build up a thickness (about 5 mm). In addition, the arc spraying apparatus is characterized by high adhesion of the sprayed coating, easy operation, high energy efficiency, and low running cost compared to other spraying apparatuses.

  And the concrete component of the range which has become clear that it can be used at the present stage as a wire which is the thermal spray material said here is described below. Aluminum-based wires include pure aluminum (purity 99.00% by mass or more), aluminum-manganese alloy, aluminum-magnesium alloy, aluminum-magnesium-silicon alloy, aluminum-copper-magnesium alloy, aluminum-zinc-magnesium alloy, aluminum -Copper alloy, aluminum-copper-nickel alloy, aluminum-silicon alloy, etc.

  As copper-based wires, pure copper (purity 99.5% by mass or more), copper-zinc alloy, copper-zinc-tin alloy, copper-zinc-aluminum alloy, copper-zinc-iron alloy, copper-zinc-manganese alloy, Examples thereof include a copper-zinc-nickel alloy, a copper-zinc-iron-manganese-aluminum alloy, a copper-tin alloy, a copper-tin-zinc alloy, a copper-tin-phosphorus alloy, and a copper-chromium alloy.

  Zinc-based wires include pure zinc (purity 99.00% by mass or more), zinc-aluminum-magnesium alloy, zinc-aluminum-copper-magnesium alloy, zinc-aluminum-copper alloy, zinc-aluminum-copper-titanium-chromium. Alloy, zinc-aluminum-copper-magnesium-titanium-beryllium alloy, zinc-manganese alloy and the like.

  Examples of the tin-based wire include pure tin (purity 99.00% by mass or more), tin-bismuth alloy, tin-lead alloy, tin-bismuth-lead-antimony alloy, and the like.

  Examples of the iron-based wire include pure iron (purity 99.8% by mass or more), silicon-iron alloy, manganese-iron alloy, chromium-iron alloy, tungsten-iron alloy, and the like.

  By using the various wires described above, formation of a thermal spray coating of any material of iron or iron-based alloy, aluminum or aluminum-based alloy, copper or copper-based alloy, zinc or zinc-based alloy, tin or tin-based alloy Is possible.

  And in the manufacturing method of the cast iron member for casting according to the present invention, it is preferable that the molten metal droplets are injected at an air pressure of 20 PSI to 70 PSI of a thermal spray gun as the thermal spraying device. When the air pressure is less than 20 PSI, the adhesion stability of the droplet splash formed when the droplet reaches the surface of the cast iron member becomes unstable, and the adhesion to the cast iron member surface as a sprayed coating decreases. Therefore, it is not preferable. On the other hand, if the air pressure exceeds 70 PSI, the droplet splash reaches the surface of the cast iron member, and the droplet splash formed is too wide. Therefore, it is difficult to obtain the height of the protrusion, and the air pressure is reduced. The thermal spraying conditions become more unstable than when less than 20 PSI, which is not preferable.

Form of cylinder liner according to the present invention: The cylinder liner according to the present invention is obtained when a cylinder liner is used as the cast iron member in the cast iron member for cast-in described above, and a molten metal is provided on the outer peripheral wall surface thereof. It is characterized by comprising a sprayed coating roughened by a plurality of protrusions formed by adhering a droplet splash which has been instantly solidified by colliding with the droplet.

  When a cylinder liner provided with this rough sprayed coating is used, it is possible to provide a high-quality cylinder block by casting it regardless of the type of casting method. In the case of a cylinder liner as a cast iron member for casting according to the present invention, the thermal spray coating on the surface improves the wettability with the aluminum alloy molten metal used for casting, and the thermal spray coating with the projection shape of the cylinder liner is provided. Intrusion of the molten aluminum alloy into the inside can be facilitated, and a sufficient anchor effect can be obtained. As a result, the adhesion between the cylinder liner and the aluminum matrix is sufficiently maintained, and it is not necessary to form irregularities on the outer peripheral wall surface of the cylinder liner before forming the sprayed coating. This makes it possible to provide a low-cost and high-quality cylinder block. It becomes.

  Hereinafter, examples of the present invention will be shown, and the present invention will be described in more detail.

Production of cast iron member: Production of cast iron member: 3.3% by mass of carbon, 1.95% by mass of silicon, 0.75% by mass of manganese, 0.2% by mass of phosphorus, 0.06% by mass of sulfur, A molten metal comprising 0.15% by mass of copper, 0.16% by mass of chromium and the balance of iron and inevitable impurities was prepared. A cast member made of A-type graphite cast iron corresponding to a cylinder liner was manufactured by a sand casting method using the molten metal having this composition. The cast member at this time has an inner diameter of 85.57 mm, an outer diameter of 104.07 mm, and a length of 133.6 mm.

Production of cast iron member: Then, in order to form an uneven surface on the surface of the cast member, spiral grooves were formed on the outer peripheral surface by cutting. A cylinder liner sample was manufactured as a cast iron member having a predetermined surface roughness with a tip R of the cutting tool used at this time of 0.4 mm, a groove pitch of 0.48 mm, and a groove depth of 0.08 mm. Thereafter, further blasting was performed using Alundum F24 as a blasting material under conditions of an injection pressure of 0.5 MPa, a work distance of 100 mm, and an injection time of 5 minutes to adjust the surface roughness to obtain a cast iron member.

Production of cast iron member with thermal spray coating: Smart Arc. Manufactured by Sulzer Metco Japan Co., Ltd. as a thermal spraying device. , While rotating a cylinder liner, which is a cast iron member, at a speed of 30 m / min to 630 m / min, a spraying speed of 0.5 mm / sec to 30 mm / sec, a spraying distance of 40 mm, a current of 100 A to 150 A, and an air pressure of 20 PSI A thermal spray coating was formed on the surface of the cylinder liner using HIGH PLOFILE SPRAY AIR CAP. Moreover, the cast iron member with a thermal spray coating produced a plurality of samples 1A to 4A and a plurality of samples 1F to 4F using an iron wire using an aluminum wire as a thermal spray wire.

Casting test: After casting, a plurality of cast iron members for casting (Sample 1A to Sample 4A, Sample 1F to Sample 4F) obtained as described above were used for an inner diameter of 91.9 mm, an outer diameter of 113.2 mm, and a length. Only the outer peripheral wall surface was cast with an aluminum alloy (ADC12) so as to be 127.6 mm. As the conditions of the cast-in, those assuming high pressure and those assuming low pressure were used. The assumed conditions in the case of high-pressure casting were a casting pressure of 62.8 MPa, a molten metal temperature of 700 ° C. to 740 ° C., a mold temperature of 140 ° C. to 180 ° C., and a cylinder liner preheating temperature of 250 ° C. using a 330 t die cast machine. Assumed conditions for low-pressure casting were a casting pressure of 3.7 × 10 ⁻³ MPa, a molten metal temperature of 700 ° C., a mold temperature of 230 ° C. to 250 ° C., and a cylinder liner preheating temperature of 230 ° C. to 250 ° C.

  Then, as shown in FIG. 6, the adhesion evaluation test piece S is a cast iron member with a cast sprayed coating (cast cylinder coated spray liner) obtained by casting a cylinder liner which is a cast iron member 1 for casting. 10 at the position of 20 mm from the end face on the side of the gates 3a, 3b, 3c, 3d, and cut into 20 mm widths, and as shown in FIG. 6 (A), the lower part of the gates 3a, 3b, 3c, 3d A 20 mm square sample was taken from the portion corresponding to. FIG. 6B is a view showing the position of the gate so that it can be clearly understood. Then, as shown in FIG. 7, the adhesion evaluation test piece S in which the aluminum alloy layer 4 and the cylinder liner 2 used for casting are layered is bonded to the tensile test jig 5 with an adhesive. The adhesion was evaluated by fixing and pulling to the arrow side in FIG. 7 and conducting a tensile test. In addition, the 18 types of samples are Sample 1A to Sample 4A and Sample 1F to Sample 4F, and Table 1 shows the results of the adhesion evaluation after the cast-in test. In addition, the numerical value shown by adhesive strength is quantified as a ratio which set the adhesive strength to 1 when the cast iron member outer periphery is a cast skin.

  Furthermore, regarding the assumed conditions in the case of low-pressure casting, the hot water flowability was also confirmed. As a confirmation method, the adhesion state between the sprayed coating and the molten metal on the cut surface of the sample was observed with a microscope from a cross section, and the adhesion state at the interface was confirmed.

  The results of the cast-in test of the examples are shown in Tables 1 and 2. Regarding the hot water flowability in the table, the case where there was no gap in the above-mentioned close contact state was indicated as ◯, the case where a gap having no practical problem was recognized, and the case where a gap having a practical problem was recognized as x. In addition, regarding the comprehensive evaluation in the table, the case where the quality required for practical use is far exceeded, ◎, the case where quality is required for practical use, and the case where the quality is less than that required for practical use are indicated as x. As a precaution, the listed contents are listed in Table 1.

  Sample 1A has a projection height of 0.05 mm to 1.0 mm, an adhesion length of projections of 0.05 mm to 0.5 mm, an adhesion width of 0.05 mm to 0.1 mm, and a thermal spray area ratio of a cast iron member outer peripheral wall surface. In contrast, 81%, the adhesion strength at high pressure assumed casting is 1.9, the adhesion strength at low pressure assumed casting is 1.3, and the molten metal flowability is good.

  Sample 2A has a projection height of 0.1 mm to 8.0 mm, an adhesion length of the projection of 0.05 mm to 10.0 mm, an adhesion width of 0.1 mm to 6.0 mm, and a thermal spray area ratio of the outer peripheral wall surface of the cast iron member On the other hand, the adhesion strength at high pressure assumed casting is 1.4%, the adhesion strength at low pressure assumed casting is 2.0, and the molten metal flow is good.

  Sample 3A has a projection height of 0.1 mm to 8.0 mm, an adhesion length of the projection of 0.1 mm to 30.0 mm, an adhesion width of 0.1 mm to 6.0 mm, and a thermal spray area ratio of the outer peripheral wall surface of the cast iron member. On the other hand, the adhesion strength at high pressure assumed casting is 1.5%, the adhesion strength at low pressure assumed casting is 2.2, and the molten metal flow is good.

  Sample 4A has a protrusion height of 0.5 mm to 10.0 mm, an adhesion length of the protrusion of 0.5 mm to 40.0 mm, an adhesion width of 0.5 mm to 10.0 mm, and a sprayed area ratio of the outer surface of the cast iron member. In contrast, the adhesion strength at high-pressure assumed casting is 2.1%, the adhesion strength at low-pressure assumption casting is 1.5, and the hot-water flow is somewhat good.

  Sample 1F has a projection height of 0.05 mm to 1.2 mm, an adhesion length of the projection of 0.05 mm to 0.7 mm, an adhesion width of 0.05 mm to 0.1 mm, and a thermal spray area ratio of the cast iron member outer peripheral wall surface In contrast, the adhesion strength at high pressure assumed casting is 1.6%, the adhesion strength at low pressure assumed casting is 1.1, and the molten metal flowability is good.

  Sample 2F has a projection height of 0.1 mm to 8.2 mm, an adhesion length of the projection of 0.05 mm to 11.0 mm, an adhesion width of 0.2 mm to 6.0 mm, and a thermal spray area ratio of the outer peripheral wall surface of the cast iron member On the other hand, the adhesion strength at high pressure assumed casting is 1.2%, the adhesion strength at low pressure assumed casting is 1.2, and the molten metal flowability is good.

  Sample 3F has a projection height of 0.1 mm to 8.2 mm, an adhesion length of the projection of 0.1 mm to 28.0 mm, an adhesion width of 0.2 mm to 6.0 mm, and a thermal spray area ratio of the outer peripheral wall surface of the cast iron member In contrast, the adhesion strength at high pressure assumed casting is 42%, the adhesion strength at low pressure assumed casting is 2.2, and the molten metal flowability is good.

  Sample 4F has a projection height of 0.8 mm to 10.0 mm, an adhesion length of the projection of 0.7 mm to 40.0 mm, an adhesion width of 0.7 mm to 10.0 mm, and a thermal spray area ratio of the cast iron member outer peripheral wall surface. In contrast, the adhesion strength at high pressure assumed casting is 1.9%, the adhesion strength at low pressure assumed casting is 1.1, and the molten metal flow is slightly good.

Comparative example

[Comparative Example 1]
The comparative example 1 produced the comparative sample which is not contained in the range of the cast iron member for casting according to this invention, changing the manufacturing conditions in an Example. This comparative sample is shown in Table 1 as Comparative A1 to Comparative A7, and is shown so that it can be compared with Samples 1A to 4A of Examples in which an aluminum sprayed coating was formed. In the following, the evaluation results of the comparative samples are shown just in case.

  Comparative A1 has a protrusion height of 0.04 mm or less, an adhesion length of the protrusion of 0.05 mm to 0.5 mm, an adhesion width of 0.05 mm to 0.1 mm, and a thermal spray area ratio with respect to the outer wall surface of the cast iron member. 93%, adhesion strength at high pressure assumed casting is 0.7, adhesion strength at low pressure assumption casting is 0.8, and hot water flowability is good.

  In comparison A2, the projection height is 0.05 mm to 1.0 mm, the adhesion length of the projection is 0.05 mm to 0.3 mm, the adhesion width is 0.04 mm or less, and the spray area ratio is relative to the outer peripheral wall surface of the cast iron member. 80%, adhesion strength at high pressure assumed casting is 0.7, adhesion strength at low pressure assumption casting is 1.0, and hot water flow is good.

  Comparative A3 has a projection height of 0.1 mm to 8.0 mm, an adhesion length of the projection portion of 0.05 mm to 30.0 mm, an adhesion width of 0.1 mm to 6.0 mm, and a thermal spray area ratio of the cast iron member outer peripheral wall surface On the other hand, the adhesion strength at high pressure assumed casting is 0.8%, the adhesion strength at low pressure assumed casting is 0.9, and the molten metal flowability is good.

  Comparative A4 has a projection height of 0.1 mm to 10.0 mm, an adhesion length of the projection of 0.5 mm to 40.0 mm, an adhesion width of 0.5 mm to 11.0 mm, and a thermal spray area ratio of the cast iron member outer peripheral wall surface On the other hand, the adhesion strength at high pressure assumed casting is 1.8%, the adhesion strength at low pressure assumed casting is 1.2, and the molten metal flow is slightly good.

  In comparison A5, the projection height is 11.0 mm or more, the adhesion length of the projection is 0.1 mm to 40.0 mm, the adhesion width is 0.1 mm to 5.0 mm, and the spray area ratio is relative to the outer peripheral wall surface of the cast iron member 95%, adhesion strength at high pressure assumed casting is 1.5, adhesion strength at low pressure assumption casting is 1.1, and hot water flowability is poor.

  In comparison A6, the projection height is 0.05 mm to 1.0 mm, the adhesion length of the projection is 0.04 mm or less, the adhesion width is 0.05 mm to 0.1 mm, and the spray area ratio is relative to the outer peripheral wall surface of the cast iron member. 80%, adhesion strength at high pressure assumed casting is 0.8, adhesion strength at low pressure assumption casting is 0.8, and hot water flow is good.

  Comparative A7 has a projection height of 1.0 mm to 10.0 mm, an adhesion length of the projection of 0.5 mm to 42.0 mm, an adhesion width of 0.1 mm to 10.0 mm, and a thermal spray area ratio of the cast iron member outer peripheral wall surface On the other hand, 99%, the adhesion strength at the time of high pressure assumed casting is 2.0, the adhesion strength at the time of low pressure assumption casting is 1.4, and the molten metal flow property is somewhat good.

[Comparative Example 2]
The comparative example 2 changed the manufacturing conditions in an Example and created the comparative sample which is not contained in the range of the cast iron member for casting according to this invention. The comparative samples are shown as Comparative F1 to Comparative F7 in Table 2 so that they can be compared with Samples 1F to 4F of Examples in which an iron spray coating was formed. In the following, the evaluation results of the comparative samples are shown just in case.

  Comparative F1 has a protrusion height of 0.04 mm or less, a protrusion adhesion length of 0.05 mm to 0.5 mm, an adhesion width of 0.05 mm to 0.1 mm, and a thermal spray area ratio with respect to the outer wall surface of the cast iron member. 93%, adhesion strength at high pressure assumed casting is 0.5, adhesion strength at low pressure assumption casting is 0.4, and hot water flowability is good.

  Comparative F2 has a protrusion height of 0.05 mm to 1.0 mm, an adhesion length of the protrusion of 0.05 mm to 0.4 mm, an adhesion width of 0.04 mm or less, and a thermal spray area ratio with respect to the outer wall surface of the cast iron member. 80%, adhesion strength at high pressure assumed casting is 0.6, adhesion strength at low pressure assumption casting is 0.8, and hot water flow is good.

  In comparison F3, the protrusion height is 0.1 mm to 8.0 mm, the protrusion adhesion length is 0.05 mm to 31.0 mm, the adhesion width is 0.1 mm to 6.0 mm, and the thermal spray area ratio is the outer peripheral wall surface of the cast iron member. On the other hand, the adhesion strength at high pressure assumed casting is 0.5%, the adhesion strength at low pressure assumed casting is 0.6, and the molten metal flowability is good.

  In comparison F4, the protrusion height is 0.1 mm to 10.0 mm, the protrusion adhesion length is 0.7 mm to 40.0 mm, the adhesion width is 0.8 mm to 11.0 mm, and the sprayed area ratio is the outer wall surface of the cast iron member. In contrast, the adhesion strength at high pressure assumed casting is 1.5%, the adhesion strength at low pressure assumption casting is 1.0, and the molten metal flowability is good.

  In comparison F5, the projection height is 11.0 mm or more, the adhesion length of the projection is 0.1 mm to 40.0 mm, the adhesion width is 0.1 mm to 5.0 mm, and the thermal spray area ratio is relative to the outer peripheral wall surface of the cast iron member 95%, adhesion strength at high pressure assumed casting is 1.2, adhesion strength at low pressure assumed casting is 1.0, and hot water flowability is poor.

  In comparison F6, the projection height is 0.05 mm to 1.0 mm, the adhesion length of the projection is 0.04 mm or less, the adhesion width is 0.05 mm to 0.1 mm, and the spray area ratio is relative to the outer peripheral wall surface of the cast iron member. 82%, adhesion strength at high pressure assumed casting is 0.5, adhesion strength at low pressure assumed casting is 0.5, and hot water flow is good.

Comparative F7 has a projection height of 1.0 mm to 10.0 mm, an adhesion length of the projection of 0.5 mm to 42.0 mm, an adhesion width of 0.2 mm to 10.0 mm, and a sprayed area ratio of the outer surface of the cast iron member. In contrast, the adhesion strength at high pressure assumed casting is 1.8%, the adhesion strength at low pressure assumed casting is 1.3, and the molten metal flowability is slightly good.

<Findings that can be understood from the comparison between Examples>
First, referring to Table 1, when the sample 2A and the sample 3A, which are samples having the same height and width of the protrusion, but different in the length of the protrusion and the sprayed area ratio, are compared, The adhesion length of the part is 0.1 mm to 30.0 mm for the sample 3A, whereas 0.05 mm to 10.0 mm for the sample 2A, and the sprayed area ratio is 40% for the sample 3A, whereas the sample 2A is 31%. %, Sample 2A has a slightly smaller coating area than sample 3A. Here, looking at the adhesion strength in Table 1, the adhesion strength of the sample 3A when the assumed high-pressure casting is 1.5 and the adhesion strength when assuming the low-pressure casting is 2.2, whereas the sample 2A is It can be seen that the adhesion strength is low at 1.4 when the high-pressure casting is encased and the adhesion strength when the low-pressure casting is 2.0. This finding is similar to the comparison between sample 2F and sample 3F in Table 2.

  Next, referring to Table 1, attention is paid to the area ratio and the protrusion height. First, the sample 3A and the sample 1A are compared. The film adhesion area ratio is as large as 81% for sample 1A compared to 40% for sample 3A. However, the adhesion strength at the time of low-pressure casting was as low as 1.3 for sample 1A compared to 2.2 for sample 3A. At this time, when it sees about the height of the projection part of the sample 1A, it turns out that 0.05 mm-1.0 mm and the thing of the projection part height of 0.05 mm of the lower limit of this invention conditions are included. Next, the sample 3A and the sample 4A are compared. The film adhesion area ratio is as high as 98% for sample 4A compared to 40% for sample 3A. However, the adhesion strength at the time of low-pressure casting was as low as 1.5 for sample 4A and 1.5 for sample 4A. At this time, when it sees about the height of the projection part of 4A of samples, it turns out that the thing of the projection part height of 10.0 mm of the upper limit of 0.5 mm-10.0 mm and this invention conditions is included. This finding is similar to the comparison between the sample 3F, the sample 1F, and the sample 4F in Table 2.

<Contrast between Example and Comparative Example>
About an Example and a comparative example, it contrasts focusing on the publication content of Table 1. First, the comparison A1 of the comparative example in which the height of the protrusion is lower than the appropriate condition of the present invention is compared with the comparison A1 and the sample 1A of the example having the same adhesion width of the protrusion (Table 2). In this case, this corresponds to the comparison between the comparative F1 of the comparative example and the sample 1F of the example.). At this time, in terms of the sprayed area ratio, the sample 1A is 81%, while the comparative A1 is 93% and the sprayed area is wide. However, looking at the adhesion strength in Table 1, the adhesion strength of the sample 1A at the time of high-pressure casting is 1.9, and the adhesion strength at low-pressure casting is 1.3, whereas the comparison A1 is It can be seen that the adhesion strength is 0.7 when the high pressure assumed casting is close and the adhesion strength when the low pressure assumption casting is 0.8.

  Next, comparison A5 of the comparative example in which the height of the protrusion is higher than the appropriate condition of the present invention is compared with the comparison A5 and the sample 4A of the example in which the adhesion area of the sprayed coating is substantially the same (Table 2). In this case, this corresponds to the comparison between the comparison F5 of the comparative example and the sample 4F of the example). At this time, the thermal spray area ratio is almost the same as 98% for the sample 4A and 95% for the comparative A5. However, looking at the adhesion strength in Table 1, the adhesion strength at the time of high pressure assumed casting of the sample 4A is 2.1 and the adhesion strength at the low pressure assumption casting is 1.5, whereas the comparison A5 is more It can be seen that the adhesion strength at low pressure assumed casting is 1.5, and the adhesion strength at low pressure assumption casting is 1.1, which is low.

  Next, for samples having the same protrusion height but different protrusion attachment widths, the comparison A2 of the comparative example in which the protrusion attachment width is shorter than the appropriate condition of the present invention and the same protrusion height as this comparison A2 This is compared with the sample 1A of this example (in the case of Table 2, this corresponds to the comparison between the comparison F2 of the comparative example and the sample 1F of the example). At this time, the thermal spray area ratio of the sample 1A is 81%, while the comparison A2 is almost the same area as 80%. However, looking at the adhesion strength in Table 1, the adhesion strength of the sample 1A at the time of high-pressure casting is 1.9, and the adhesion strength at low-pressure casting is 1.3, whereas the comparison A2 is It can be seen that the adhesion strength is low at 0.7 when the high-pressure casting is encased and the adhesion strength when low-pressure casting is 1.0.

  Next, the comparison A4 of the comparative example including the protrusion adhesion width exceeding the appropriate condition of the present invention is compared with the comparison A4 and the sample 4A of the example in which the height of the protrusion is substantially the same. (In the case of Table 2, this corresponds to the comparison between the comparison F4 of the comparative example and the sample 4F of the example). At this time, the thermal spray area ratio of the sample 4A is 98%, while the comparison A4 is almost the same area as 100%. Here, looking at the adhesion strength in Table 1, the adhesion strength of the sample 4A at the time of high-pressure assumed casting is 2.1, and the adhesion strength at the time of low-pressure assumption casting is 1.5, whereas the comparison A4 is more It can be seen that the adhesion strength at low pressure assumed casting is 1.8, and the adhesion strength at low pressure assumption casting is 1.2, indicating low adhesion.

  Next, for the samples having the same height of the protrusion and the adhesion width of the protrusion and different spray areas, the comparison A3 of the comparative example in which the spray area ratio is smaller than the appropriate condition of the present invention, and the comparison A3 and the protrusion The sample 2A of the example having the same height and the adhesion width of the protrusion is compared (in the case of Table 2, this corresponds to the comparison of the comparison F3 of the comparative example and the sample 2F of the example). At this time, the thermal spray area ratio of Sample 2A is 31%, and the thermal spray area ratio of Comparative A3 is 20%. Here, looking at the adhesion strength in Table 1, the adhesion strength of the sample 2A at the time of assumed high-pressure casting is 1.4 and the adhesion strength at the assumption of low-pressure casting is 2.0, whereas the comparison A3 is more It can be seen that the adhesion strength is low, with an adhesion strength of 0.8 at the time of high pressure assumed casting and an adhesion strength of 0.9 at the low pressure assumption casting.

  Finally, with respect to the samples having different protrusion adhesion lengths, first, the sample 1A and the comparison A6 are compared. In the sample 1A and the comparison A6, the height of the protrusion and the attachment width of the protrusion are both the same, and the thermal spray area ratio is also substantially the same. However, while the adhesion length of the protrusions of the sample 1A is within the appropriate condition range of the present invention, in comparison A6, the adhesion length of the protrusions is shorter than the appropriate conditions of the present invention. Here, looking at the adhesion strength in Table 1, the adhesion strength of the sample 1A at the time of high-pressure casting is 1.9, and the adhesion strength at the time of low-pressure assumption casting is 1.3, whereas the comparison A6 is better. It can be seen that the adhesion is low, with an adhesion strength of 0.8 when assuming high-pressure casting and an adhesion strength of 0.8 when assuming low-pressure casting. Next, the sample 4A is compared with the comparison A7. The sample 4A and the comparison A7 all have substantially the same height of the protrusion, the adhesion width of the protrusion, and the thermal spray area ratio. However, while the adhesion length of the protrusions of the sample 4A is within the appropriate condition range of the present invention, the comparison A6 includes a protrusion whose adhesion length is longer than the appropriate conditions of the present invention. . Here, looking at the adhesion strength in Table 1, the adhesion strength of the sample 4A at the time of high-pressure casting is 2.1, and the adhesion strength at low-pressure assumption of casting is 1.5, whereas the comparison A7 is more It can be seen that the adhesion strength is 2.0, and the adhesion strength at low pressure assumed casting is 2.0, and the adhesion strength at low pressure assumption casting is 1.4, which is slightly lower.

  From the comparison between the examples described above and the comparison between the examples and the comparative example, it is understood that the preferable range of the protrusion height is 0.05 mm to 10 mm, and the more preferable range is 0.1 mm to 8 mm. This is because if the height of the protrusion is low, the adhesiveness is lowered, and if the height of the protrusion is high, the hot water flow property is deteriorated. And it turns out that the preferable range of the adhesion width | variety of a projection part is 0.05 mm-10 mm, and a more preferable range is 0.1 mm-6 mm. This is because if the adhesion width of the protrusions is narrow, the adhesion is lowered, and if the adhesion width of the protrusions is wide, the adhesion becomes nonuniform. It can be seen that the preferable range for the adhesion length of the protrusion is 0.05 mm to 40 mm, and the more preferable range is 0.1 mm to 30 mm. This is because if the adhesion length of the protrusion is short, the adhesion is lowered, and if the adhesion length of the protrusion is long, the hot water flow property is deteriorated and the adhesion is also deteriorated. Furthermore, it can be seen that the preferred range of the sprayed area ratio is 30% or more, and the more preferred range is 40% or more. This is because if the thermal spray area ratio is small, the heat shrinkability and the adhesiveness are lowered.

  In addition, although the above-mentioned findings and comparisons have been described with a focus on the contents listed in Table 1, the same results can be obtained even when an iron-based material is used instead of an aluminum-based material in Table 2. I will state that again here.

  The cast iron member for casting according to the present invention is provided with a thermal spray coating having a unique and extremely rough protrusion on the outer peripheral wall surface. As a result, when cast with an aluminum matrix, the projection shape of the sprayed coating penetrates deeply into the aluminum matrix regardless of the type of casting method such as low pressure casting or high pressure casting, and exhibits a good anchoring effect. To do. As a result, the cast iron member for casting according to the present invention obtains good adhesion with the matrix material when processed into a casting without forming irregularities in advance on the outer peripheral wall surface of the cast iron member before spraying. I can do it. In addition, the projection shape of the thermal spray coating includes fine needle, sponge, and plate-shaped droplet splash shapes, so it has excellent thermal conductivity and is easily melted by the heat of the molten aluminum alloy during casting. In addition, mutual diffusion is likely to occur at the interface between the sprayed coating and the aluminum matrix, a good metal bonding state can be obtained, and good adhesion can be obtained. Even with an iron-based film, a sufficient anchoring effect can be obtained and good adhesion can be obtained. Therefore, the cast iron member for cast-in can be suitably applied to a cylinder liner for an internal combustion engine, a wear-resistant piston trailer material, or the like.

It is the external appearance photograph observed with the microscope of the sprayed coating of the cast iron member for casting according to this invention. It is the external appearance photograph observed with the microscope of the sprayed coating of the cast iron member for casting according to this invention. It is the external appearance photograph observed with the microscope of the sprayed coating of the cast iron member for casting according to this invention. It is the observation image of the narrow area | region which observed the sprayed coating of the cast iron member for casts concerning this invention with the scanning electron microscope. It is a conceptual diagram for demonstrating the projection part of the cast iron member for cast-ins according to this invention. It is a conceptual diagram for demonstrating the collection position of the adhesive evaluation test piece from the cast cylinder liner. It is a conceptual diagram of the tension test at the time of performing adhesiveness evaluation using an adhesiveness evaluation test piece.

Explanation of symbols

1 Cast Iron Member for Casting 2 Cast Iron Member (Cylinder Liner)
3a, 3b, 3c, 3d Sprue 4 Aluminum alloy layer 5 Tensile test jig 10 Cast iron member with cast sprayed coating 20 Protrusion shape C Protrusion area circumscribed circle H Protrusion height L Protrusion area maximum length W Protrusion Area maximum width S Adhesion evaluation test piece

Claims (13)

A cast iron member for casting with a cylindrical shape provided with a roughened outer peripheral wall surface,
The outer peripheral wall surface was roughened by a plurality of protrusions formed by adhering molten metal droplets that collided with instantaneously solidified droplets onto the outer peripheral wall surface of a cylindrical cast iron member that rotates at high speed in the circumferential direction. A cast iron member for casting, comprising a thermal spray coating. The cast iron member for casting according to claim 1, wherein the protrusion is configured to include a droplet splash shape having a needle shape, a sponge shape, and a plate shape. The cast iron member for casting according to claim 1 or 2, wherein the protrusion has a height of 0.05 mm to 10 mm and an adhesion width of the droplet splash is 0.1 mm to 10 mm. The cast iron member for cast-in according to any one of claims 1 to 3, wherein the protrusion has an adhesion length of the droplet splash of 0.05 mm to 40 mm. When the outer peripheral wall surface area of the cast-in cast iron member for cylindrical casting is 100% by area, the area ratio of the region to which the sprayed material adhering to the outer peripheral wall surface is 30% by area or more of the outer peripheral wall surface. The cast iron member for cast-in according to any one of claims 1 to 4. The thermal spray coating is made of any material of iron or iron-based alloy, aluminum or aluminum-based alloy, copper or copper-based alloy, zinc or zinc-based alloy, tin or tin-based alloy. A cast iron member for casting. The cast iron member according to any one of claims 1 to 6, wherein the cast iron member has a groove-like uneven shape formed on an outer peripheral wall surface thereof. The cast iron member for casting according to any one of claims 1 to 7, wherein the cast iron member has a roughened surface by blasting on an outer peripheral wall surface thereof. The cast iron member for cast-in according to any one of claims 1 to 8, wherein a cylinder liner is used as the cast iron member, and droplets of molten metal collide with the outer peripheral wall surface, and a droplet solidified instantly adheres to the outer peripheral wall surface. A cylinder liner for cast-in, which is provided with a sprayed coating roughened by a plurality of protrusions formed. It is a manufacturing method of the cast iron member for cast-in in any one of Claims 1-8,
A cylindrical cast iron member is pivotally supported, and a molten metal droplet is made to collide with the outer peripheral wall surface of the cast iron member rotating at a high rotational speed in the circumferential direction at a rotational speed of 30 m / min to 630 m / min using a thermal spraying device to instantly solidify. A method for producing a cast iron member for cast-in wrapping, comprising: forming a sprayed coating roughened by a plurality of protrusions formed by adhering a droplet splash formed on the outer peripheral wall surface of the cast iron member. The manufacturing method of the cast iron member for cast-in of Claim 10 using an arc spraying apparatus as the said thermal spraying apparatus. The method for producing a cast iron member for casting according to claim 10 or 11, wherein the molten metal droplets are injected at an air pressure of 20 PSI to 70 PSI of a thermal spray gun as the thermal spraying device. The material according to any one of claims 10 to 12, wherein any one of iron or iron-based alloy, aluminum or aluminum-based alloy, copper or copper-based alloy, zinc or zinc-based alloy, tin or tin-based alloy is used as the molten metal. A method for producing a cast iron member for casting.