JPH08246164A - Metal-based composite material and method for producing the same - Google Patents

Abstract

(57) [Summary] [Purpose] The adhesion of the iron plating layer 4 is increased, and the wear resistance,
To provide a metal matrix composite material having excellent seizure resistance. [Structure] A composite material layer 2 made of an ADC12 alloy and alumina fibers is used, and the composite material layer 2 is acid-etched to expose a part of the alumina fibers. Next, the etched surface is subjected to iron plating by electroplating, and a mixed layer 3 composed of alumina fibers and an iron plated portion, and further an iron plated layer 4 are laminated. After that, the iron plating layer 4 is subjected to honing finish processing.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a metal matrix composite material and a method for producing the same. The present invention is, for example, an aluminum-based sliding member,
Specifically, it can be applied to a bore portion of a cylinder block of an engine, a ring groove portion of a piston, an engine valve, a groove portion of a pulley belt, and the like.

[0002]

In Japanese Patent Publication No. 57-33089, a metal matrix composite material having an aluminum alloy as a matrix is used.
A technique is disclosed in which the surface layer portion is subjected to an etching treatment to expose the reinforcing fibers, and the surface thereof is subjected to anodization treatment to laminate an alumite layer.

Also, in this publication, a metal matrix composite material having an aluminum alloy as a matrix is used, and the surface layer portion thereof is subjected to electrolytic etching treatment to expose reinforcing fibers, and a piano wire steel material and a high chromium alloy are provided on the surface thereof. A technique is disclosed in which steel and high carbon steel are deposited by a thermal spraying method to form an iron-based thermal spray layer.

[0004]

However, the alumite layer according to the above publication does not necessarily have sufficient wear resistance and seizure resistance. The quality of the alumite layer is easily affected by the material of the material to be treated. In particular, it is generally said that an aluminum alloy containing an alloying element such as Si or Cu is likely to induce nonuniformity of the alumite layer. Especially ADC12 alloy widely used as die-cast material (Si is 1
1 wt% content) is likely to induce non-uniformity of the alumite layer when anodizing.

Further, in the explosive spraying method according to the above publication, the sprayed powder particles, at least a part of which is in a molten state, collide with each other at a super high speed of several times the speed of sound. There are problems such as oxidation of the alloy and ejection of gas, and it is difficult to obtain good adhesion, and at the same time, there is a problem that the entire material is deformed. The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to eliminate the alumite treatment and the thermal spraying treatment by anodization and adopt the iron-based plating treatment, while suppressing the damage of the exposed reinforcing fiber. , Straddling the reinforcing fiber between the iron-based plating layer and the composite material layer to improve the adhesion of the iron-based plating layer,
Accordingly, it is an object of the present invention to provide a metal-based composite material which is advantageous in improving wear resistance and seizure resistance, and a method for producing the same.

[0006]

A metal-based composite material according to claim 1 is a composite material layer comprising an aluminum alloy matrix and reinforcing fibers embedded in the matrix, and a composite material layer laminated on the composite material layer. A mixed layer in which reinforcing fibers protruding from a material layer and an iron-based plated portion are mixed, and a mixed layer, which is provided with an iron-based plated layer of the same type as the iron-based plated portion of the mixed layer Is.

A method of manufacturing a metal-based composite material according to a second aspect uses a member having a composite material layer including an aluminum alloy matrix and reinforcing fibers embedded in the matrix, and the composite material layer of the member is A step of etching the surface layer part to expose a part of the reinforcing fibers constituting the composite material layer, and an iron-based plating process on the surface layer part of the composite material layer where the reinforcing fiber is exposed, and stacking the iron-based plating layer And the step of performing.

[0008]

According to the first aspect, since the outermost layer is formed of the iron-based plating layer, wear resistance and seizure resistance are improved. Further, the reinforcing fibers are present so as to extend over both the composite material layer and the iron-based plating layer, and the iron-based plating portion of the composite material layer and the mixed layer and the iron-based plating layer laminated on the mixed layer are formed. Connect firmly.

Further, according to the manufacturing method of claim 2, the surface layer portion of the composite material layer is etched to expose a part of the reinforcing fibers constituting the composite material layer, and iron-based plating is applied thereon. As a result, the reinforcing resin can be spread over both the composite material layer and the iron-based plating layer.

[0010]

According to the first aspect of the present invention, since the outermost surface layer is formed of the iron-based plating layer, wear resistance and seizure resistance are improved. Furthermore, since the reinforcing fibers embedded in the composite material layer extend over both the composite material layer and the iron-based plating layer, the adhesion of the iron-based plating portion of the mixed layer and the iron-based plating layer laminated on the mixed layer Is improved. Therefore, it is advantageous for maintaining good wear resistance and seizure resistance due to the iron-based plating layer for a long period of time even in a severe operating environment.

According to the second aspect, it is possible to easily form a structure in which the reinforcing fiber extends over both the composite material layer and the iron-based plating layer. Also, when forming the outermost iron-based plating layer,
Since the reinforcing fibers can be straddled on both sides, the structure of claim 1 can be easily formed. According to the first and second aspects, since the iron-based plating layer is formed by the plating process, unlike the explosive spraying method, damage to the reinforcing fiber due to collision at an ultra high speed,
It is advantageous to suppress the drop-off, and therefore, the degree to which the reinforcing fiber extends over the composite material layer and the iron-based plating portion is improved, which is advantageous for improving the adhesion of the iron-based plating layer.

According to the first and second aspects, the effect of removing the oxide film on the surface layer of the composite material layer by the etching treatment can be expected, and in this sense, it is advantageous for improving the adhesion of the iron-based plating layer.

[0013]

【Example】

(General Example) A conceptual diagram of a metal-based composite material according to this example is shown in FIG. As shown in FIG. 1, the metal matrix composite material is
A composite material layer 2 laminated on the aluminum alloy layer 1, a mixed layer 3 laminated on the composite material layer 2, and an iron plating layer 4 laminated on the mixed layer 3 as an iron-based plating layer. The aluminum alloy layer 1 is an aluminum alloy containing at least one of Si, Cu, Mg, Zn, Fe, and Mn. Composite material layer 2
Includes a matrix 2a formed of an aluminum alloy of the same material as the aluminum alloy layer 1, and reinforcing fibers 2c embedded in the matrix 2a.

The mixed layer 3 has reinforcing fibers 3a protruding from the composite material layer 2 and iron-plated portions 3c as iron-based plated portions held around the reinforcing fibers 3a. The reinforcing fibers 3a are of the same type as the reinforcing fibers 2c of the composite material layer 2. The iron-plated layer 4 is formed of the same material as the iron-plated portion 3c forming the mixed layer 3. This metal matrix composite material is manufactured as follows. First, a fiber molded body of reinforcing fibers is held in a state of being applied to the mold surface of a mold such as a mold.
In this case, it is preferable to bond the fibers with a binder such as an inorganic binder. Then, by a casting method such as a die casting method or a high pressure casting method, a cavity of a molding die such as a die is filled with a molten aluminum alloy, and the molten metal is impregnated into the gaps between the fibers forming the fiber molded body. When the filled aluminum alloy is solidified, a material including the aluminum alloy layer 1 and the composite material layer 2 is manufactured.

The material produced in this manner is processed into a predetermined size by machining and finished, and then the surface layer portion of the composite material layer 2 is etched to obtain the composite material layer 2
A part of the reinforcing fibers constituting the is exposed. As the etching treatment, a wet chemical etching method in which an etching solution is brought into contact with the surface layer portion of the composite material layer 2 can be adopted. In this case, acid etching is preferable, but in some cases, alkali etching, electrolytic etching or the like can be adopted or used together. This is because the aluminum alloy is easily attacked by acid and alkali. By such etching,
The removal of the oxide film on the surface of the composite material layer 2 can be expected,
It can contribute to the improvement of the adhesion of the iron plating layer 4.

Next, an iron-based plating process is performed on the surface layer portion of the composite material layer 2 where a part of the reinforcing fibers is exposed by the etching process, and an iron plating layer is laminated. As the iron-based plating treatment, electroplating, electroless plating, etc. can be adopted. In the case of electroplating, generally, an aluminum alloy layer 1 having a composite material layer 2 which is an object to be plated with reinforcing fibers exposed is used as a cathode, an iron-based metal is used as an anode, and current is applied between both electrodes. A method in which iron on the anode side is dissolved in the plating solution as ions, the iron ions are diffused and migrated to the cathode side, moved to the aluminum part of the composite material layer 2 as the cathode, and the iron ions are reduced and adhered can be adopted. . Alternatively, a solution containing an Fe component is used as a plating solution, and an aluminum alloy layer 1 having a composite material layer 2 which is an object to be plated with reinforcing fibers exposed is used as a cathode, and an electric current is applied between an insoluble anode such as platinum and the cathode. A method of diffusing and migrating iron ions to the cathode side and reducing and adhering iron ions to the aluminum portion of the composite material layer 2 as the cathode can be adopted.

In the case of such electroplating, the deposition rate of iron is basically influenced by the diffusion rate of iron ions, the migration rate, and the reduction rate of iron ions. The amount of iron plating adhered basically follows Faraday's law in electrodeposition plating. In the electroplating process, a pulse plating process in which a current-carrying period and a current-blocking period are repeated can be adopted. According to this, it is advantageous in reducing the diffusion layer that causes the uneven concentration of iron ions. In the electroplating treatment, it is possible to employ a method in which at least one of the plating solution, the composite material layer 2 on the cathode side, the anode, etc. is moved to stir the plating solution.

In the case of electroless plating, the reducing action of a plating solution containing a reducing agent is utilized to reduce and deposit iron on the aluminum portion of the composite material layer 2 which is the object to be plated. According to this embodiment, the iron plating layer 4 is finished after the iron plating treatment. As finishing processing, generally, boring processing,
Honing and polishing can be used. As a result, the thickness and surface smoothness of the iron plating layer 4 can be accurately regulated to predetermined dimensions.

In FIG. 1, the region L1 corresponds to a region removed by etching, and the region L2 corresponds to a region subjected to iron-based plating. Further, the region L3 corresponds to a composite region of the fiber molded body that is composited by casting, and also corresponds to a region that defines the shape accuracy of the exposed surface such as the bore. (Example 1) According to the metal-based composite material of Example 1,
The aluminum alloy forming the aluminum alloy layer 1 and the composite material layer 2 is a casting aluminum alloy or a JIS-ADC12 alloy. According to the JIS standard, the target composition of the ADC12 alloy is 9.6 to 12.0 wt% Si, 1.5 to 3.5 wt% Cu, and 1.3 wt% or less Fe.

According to the first embodiment, the reinforcing fibers 3a and 2c are alumina fibers and have an average diameter of 5 to 10 μm.
m, and the aspect ratio is 5 to 20. The fiber volume ratio Vf is 4%. In addition, the gap between the fibers of the fiber molding is 5 to 50.
It is about μm. According to the first embodiment, the iron-plated portion forming the mixed layer 3 and the iron-plated layer 4 is FeP plating, and is formed based on the plating treatment conditions in Table 2 described later.

According to the first embodiment, the etching solution is HNO.
₃ : 3100 cc / liter aqueous solution / room temperature / voltage 7.5
Electrolytic etching is performed by a V / current density of 23 A / dm ² for 60 seconds, and the etching depth is 2.5 to 3.5.
μm. (Application Example) FIG. 2 shows an example in which the above-described embodiment is applied to the bore of a cylinder block made of an aluminum alloy for casting of an in-vehicle engine. The cylinder block 5 as a member is, similarly to the above, an aluminum alloy-based aluminum alloy layer 1 which constitutes the main body of the cylinder block 5, a composite material layer 2 laminated on the aluminum alloy layer 1, and a composite material layer 2. Mixed layer 3
An iron plating layer 4 laminated on the mixed layer 3 is provided. The iron plating layer 4 forms the bore inner peripheral surface 50 a of the bore 50.

According to this example, a sleeve-shaped fiber molded body is held on the outer peripheral surface of the cylindrical mold portion 100 which becomes a bore, and in that state, a molding die (not shown) (generally a mold) is held. However, it may be a sand mold in some cases) is filled with a high temperature molten aluminum alloy (generally 600 to 750 ° C.), and the molten metal is impregnated into the gap between the fiber moldings, and the aluminum alloy is solidified to form a cylinder. Form block material. After that, it is machined so as to have a specified dimension: bore surface texture, and then the surface layer portion of the composite material layer 2 is brought into contact with an etching solution containing an acid to carry out an etching treatment, thereby Expose the part. After that, the iron plating layer 4 is laminated on the exposed portion by electroplating.

(Element) The elements of the above-described embodiments and application examples will be further described. The fiber volume ratio Vf of the reinforcing fibers in the composite material layer 2 of the metal-based composite material affects the strength, rigidity, and elastic modulus of the composite material layer 2. Further, when Vf is high, the resistance of the molten metal passing through the fiber molded body during casting increases, and the deformation of the fiber molded body during casting is likely to be induced. In order to suppress the deformation of the fiber molded body, it is preferable to suppress the filling speed of the molten metal, but the cooling of the molten metal is promoted, and casting defects such as shrinkage are easily induced. In addition, according to the usual die casting method for casting a cylinder block or the like, Vf of 20% is the limit in consideration of the impregnation property of the molten metal into the fiber molded body. In consideration of these circumstances, Vf of the composite material layer 2 of the metal-based composite material is preferably about 1 to 20% and about 2 to 8%. Although Vf can be selected according to the type of the metal-based composite material, the lower limit value can be 2%, 3%, 4% and the upper limit value can be 9%, 7%, 5%.

Note that Vf is based on the following equation (1). Vf (%) = {W / (ρ × V)} × 100 (1) W: weight of fiber molded body, V: apparent volume of fiber molded body, ρ: fiber density (ρ = 3. 4, ρ = 2.6 for alumina / silica fiber, ρ for mullite fiber
= 2.6) Here, the apparent volume V occupied by the fiber molded body is measured with a measuring instrument. For example, when the fiber molded body has a sleeve shape or a ring shape, the outer diameter and the inner diameter of the fiber molded body are measured with a dial gauge and a taper gauge, and the height is calculated to calculate V.

When the metal-based composite material is formed by casting, the size of the minimum gap between the fibers forming the fiber molded body is taken into consideration from the viewpoint of preventing entrapment of gas or air during casting. Preferably. The minimum gap is 0.
It can be 1 mm or less, particularly 300 μm or less. 2 of these
It is preferably 00 μm or less and 100 μm or less. By doing so, it is easy to prevent gas or entrained air contained in the molten metal that causes porosity during casting from being blocked by the fibers forming the fiber molded body so that gas defects do not occur on the product surface. Generally, the diameter of the gas or air contained in the molten metal is considered to be larger than 0.1 mm, so the minimum gap of the fiber fiber molded body is
If it is 0.1 mm or less, it is effective.

As the reinforcing fibers, metal oxide fibers, metal carbide fibers, metal nitride fibers, etc. can be selected, and specifically, alumina fibers, alumina / silica fibers, silica fibers, ceramic fibers such as mullite fibers, and metal fibers. Glass fibers such as oxynitride glass fibers can be used. In the case of improving strength and rigidity, the reinforcing fibers are preferably those having good wettability with the molten metal, those hardly reacting with the molten metal, and those having higher strength and elastic modulus than the aluminum alloy.

The diameter and aspect ratio (length / diameter) of the reinforcing fiber are selected according to the kind of the metal matrix composite material, but the upper limit of the diameter can be 50 μm, 30 μm, 25 μm and the lower limit is 1 μm, 3 μm, The diameter of the reinforcing fibers can be about 2 to 25 μm. The upper limit of the aspect ratio can be 100, 50, 30 and the lower limit can be 1 or 3, so that the aspect ratio of the reinforcing fiber can be about 5 to 25. The diameter and aspect ratio of the reinforcing fibers are obtained by grinding the composite material layer 2 and observing the optical microscope or SEM of 400 times or more.
Based on the average value observed in.

When the composite material layer 2 is integrally provided adjacent to the aluminum alloy layer 1 as in the present embodiment, the thickness of the fiber molded body forming the composite material layer 2 is the metal matrix composite. Although it is selected according to the type of material, the finished product level after machining is preferably 0.05 mm or more, and can be 1 mm or more, 2 mm or more, 3 mm or more. The upper limit is 5 mm, 10 m
It can also be m, 20 mm or the like.

If the composite material layer 2 has a required thickness, the strength, rigidity, and machining accuracy in machining are generally improved as compared with the case of a single aluminum alloy. The depth of the composite material layer 2 to be removed by the etching treatment is selected according to the length of the reinforcing fiber and the type of the metal matrix composite material, but the upper limit of the depth can be 100 μm, 50 μm, 20 μm,
The lower limit can be 0.1 μm, 0.3 μm, 1 μm. Therefore, the depth of the aluminum alloy portion to be removed by the etching process can be set to about 0.2 to 20 μm and about 0.5 to 10 μm.

The etching treatment can be carried out by immersing the composite material layer 2 in an aqueous solution of acid or alkali, or electrolytically treating the composite material layer 2 in the immersed state. The method of electrolytic etching with an aqueous solution having a relatively low concentration is easy to shorten the processing time. The electrolytic etching treatment conditions can be, for example, HNO ₃ (100 cc / liter) as the etching solution, room temperature as the temperature, 7.5 V as the voltage, and 23 A / dm ² as the current density. Under this condition, the etching depth was generally 1 μm when the treatment time was about 20 seconds, 2 μm when the treatment time was about 40 seconds, and 3 μm when the treatment time was about 60 seconds.

As the iron plating layer, Fe plating consisting essentially of Fe, FeP plating, FeCr plating, FeCr
P plating, FeNi plating, FeW plating, and FeB plating can be adopted. The hardness of the iron plating layer is MHv and the lower limit value can be 300, 350, 400, and the upper limit value is 600, 65.
It can be 0,700. Fe plating is MHv300 or more,
FeP plating is MHv400 or more, and the upper limit of the amount of P is 1.0 wt%, 6.0 wt%, 12.0 wt%, and the lower limit of 0.2 wt%, 2.0 wt%, 8.0 wt% is good. , But is not limited to this. FeCr plating, FeCrP plating, FeNi plating, FeW plating, and FeB plating can be MHv350 or higher.

The iron plating layer may be a composite plating layer in which hard particles such as ceramic particles are dispersed. The average diameter of the hard particles can have an upper limit value of about 5 μm and 3 μm, and a lower limit value of about 0.2 μm and 0.3 μm. Therefore, the hard particles are preferably about 0.5 to 4 μm, preferably about 1 μm.
Hard particles are SiC, Si ₃ N ₄ , Al ₂ O ₃ , ZrO ₂
Ceramic particles such as can be adopted. The eutectoid amount of hard particles can be set to 0.1 to 8.0 wt% when the total of iron and ceramic particles is 100 wt%.

As described above, the iron plating layer may be Fe-SiC dispersion plating or FeP plating. Table 1 shows typical forming conditions of Fe-SiC dispersion plating by electroplating, and Table 2 shows typical forming conditions of FeP plating by electroplating.

[0034]

[Table 1] The term “g / liter” means the weight contained in 1 liter of the plating solution.

[0035]

[Table 2] Here, NaH ₂ PO ₃ .2H ₂ O is a composition for precipitating P. In forming the iron-plated layer consisting essentially of the iron component, a bath containing no SiC particles can be adopted under the plating conditions shown in Table 1. Also, Table 2
From the plating conditions shown in (1), it is possible to use a bath in which NaH ₂ PO ₃ .2H ₂ O is not added. Further, in forming FeP-SiC dispersed plating, a bath in which 30 g / liter of SiC particles are added to the plating solution under the plating conditions shown in Table 2 can be adopted. (Test Example) Various tests were conducted to evaluate the above-described examples.

A wear resistance test was conducted. The test pieces according to Test Example 1 to Test Example 6 used in the wear resistance test have the form shown in FIG. 1 and correspond to the material of the present invention. That is, aluminum alloy layer 1 (corresponding to JIS ADC12), composite material layer 2, mixed layer 3, electroplated iron plating layer 4 (FeP)
Are sequentially stacked. The electroplating conditions were basically based on the conditions shown in Table 2.

In this composite material layer 2, the matrix is the same material as the aluminum alloy layer 1, that is, an aluminum alloy corresponding to ADC 12, and the reinforcing fibers are alumina fibers (having an average diameter of 5 to 5).
10 μm, average aspect ratio 5-20), and fiber volume ratio Vf is 4%. As shown in part in FIG. 4, in Test Example 1, the iron plating layer 4 was honed so that the thickness of the iron plating layer 4 was 60 μm (the thickness of the region corresponding to L2 in FIG. 1). . In Test Example 2, the iron plating layer 4 was honing-finished so that the thickness of the iron plating layer 4 was 20 μm. In Test Example 3, the iron plating layer 4 was honing-finished so that the mixed layer 3 was exposed.

Further, the test pieces according to Test Examples 4 to 6 are
It has the form shown in FIG. 1 and corresponds to the material of the present invention. That is, the aluminum alloy layer 1 (corresponding to JIS ADC12), the composite material layer 2, the mixed layer 3, and the iron plating layer 4 are laminated in this order, and in this iron plating layer 4, SiC particles are dispersed in Fe. The conditions of the electroplating treatment were basically based on the conditions shown in Table 1. In Test Example 4, an iron-plated layer containing SiC was honing-finished so that the thickness of the iron-plated layer 4 was 60 μm (the thickness of the region corresponding to L2 in FIG. 1). In Test Example 5, the thickness of the iron plating layer 4 was 2
The iron-plated layer 4 containing SiC is honing-finished so that the thickness becomes 0 μm. In Test Example 6, the iron-plated layer 4 containing SiC was honing-finished so that the mixed layer 3 was exposed.

Then, using the test pieces according to the above-mentioned Test Examples 1 to 6, a wear resistance test of LFW-1 was conducted in a form schematically shown in FIG. In this test, the mating block 71 (width: 6.5 mm, material: spring steel, which is a piston ring material, is Cr-plated) is provided on the outer peripheral surface of a ring-shaped test piece 70 (diameter: 35 mm) shown in FIG. The test piece 70 was rotated by applying a predetermined load in the arrow A1 direction and sliding the test piece 70 in the arrow A2 direction. Then, the depth of the wear mark formed on the outer peripheral surface of the test piece 70 was measured.

The test condition is that the rotation speed of the test piece 70 is 1
60 rpm, a load of 180 kg, a sliding time of 60 minutes, and the atmosphere is in an oil bath of engine oil. As Comparative Example 1, as shown in FIG. 4, a FeP plating layer (thickness: 60 μm) was electroplated on the surface layer portion (not etched) of the aluminum alloy of ADC12 that did not include the reinforcing fiber and the composite material layer. A laminated test piece was used. Comparative Example 2
As the test piece, a test piece obtained by treating the surface layer part of the aluminum alloy of ADC12 containing no reinforcing fiber with an alumite layer (thickness: 20 μm) was used. Similarly, for Comparative Examples 1 and 2, L
A FW-1 abrasion resistance test was conducted.

The test results are shown in FIG. As can be understood from FIG. 4, the wear depth was 2.0 μm in Comparative Example 1 and 3.5 μm in Comparative Example 2. On the other hand, in Test Example 1 according to the present invention material, 1.5 μm, Test Example 2 according to the present invention material
Is 1.2 μm, and in Test Example 3 according to the present invention material is 0.6 μm
m was 0.6 μm in Test Example 4 of the present invention material, 0.5 μm in Test Example 5 of the present invention material, and 0.3 μm in Test Example 6 of the present invention material. From this fact, Test Example 1
-Test Example 6 That is, it is understood that the material of the present invention has excellent wear resistance.

A seizure resistance test was conducted. In this seizure resistance test, as Test Example 7, the surface layer portion of the composite material layer 2 formed on the aluminum alloy layer 1 was etched to expose a part of the reinforcing fibers, and electroplating was performed as in the embodiment shown in FIG. An iron plating layer 4 (FeP) was laminated by the above method, and a test piece in which the mixed layer 3 and the iron plating layer 4 were laminated in this order was used. The conditions relating to the test piece are based on the above-described Example 1.

Further, as a comparative example 3, a composite material layer 2 (matrix: laminated on an aluminum alloy layer 1 corresponding to ADC 12).
ADC12, reinforcing fiber: alumina fiber, Vf: 4%), and the surface layer portion thereof is subjected to acid etching treatment by HNO ₃ : 100 cc / liter aqueous solution / room temperature / voltage 7.5V / current density 23 A / dm ² for 60 seconds. Etching depth: 3 μm), a part of the fiber was exposed, and then anodized, and anodized laminated test pieces were used.

In this seizure resistance test, a cylindrical mating material 7 was used by using a mechanical testing laboratory type friction and wear tester having a configuration shown in FIG.
4 (inner diameter: 20 mm, outer diameter: 25.6 mm, height: 17
mm, area: 2 cm ² ) toward the test piece 75 with an arrow A3
Direction, the test piece 75 was rotated in the direction of arrow A4, the pressing load was increased stepwise, and the seizure load when the seizure occurred on the test piece 75 was measured.

As the above-mentioned test conditions, the test piece 7
The rotation speed of No. 5 was 1000 rpm (= 1.2 m / sec), the load was increased by 25 kg per minute, and the atmosphere was in the oil bath of engine oil. The test results are shown in the column of sliding characteristics in Table 3. Table 3 shows the material of the cylindrical mating member 74.
Piston skirt equivalent material (that is, JIS-AC
8A equivalent aluminum alloy material, piston ring equivalent material (that is, spring steel plated with Cr), piston ring equivalent material (stainless steel JIS-SUS440B gas nitrided) were adopted.

As shown in Table 3, Test Example 7 relating to the material of the present invention
According to this, the seizure load was 450 kg for the piston skirt equivalent material, 300 kg for the piston ring equivalent material, and 350 kg for the piston ring equivalent material, and the seizure load was considerably high. On the other hand, according to Comparative Example 3, the seizure load is 250 kg for the piston skirt material, 150 kg for the piston ring, and 20 kg for the piston ring.
It was 0 kg, and the baking load was low. This shows that the iron-plated material of the present invention has better seizure resistance than the alumite-treated comparative example.

Further, a comparison of the productivity between the iron plating treatment and the alumite treatment is shown in the productivity column of Table 1. According to the alumite treatment, the film formation rate is slow. However, according to the iron plating treatment of the material of the present invention, as shown in Table 1, both the high speed method and the ordinary method have a considerably high film forming rate and good productivity. Regarding the bath temperature, according to the iron plating treatment according to the material of the present invention, Table 1
Since the temperature is 50 to 60 ° C. as shown in FIG. 7, a simple heater device can be used. However, according to the alumite treatment of the material of the present invention according to the comparative example, a temperature of 10 ° C. or less is preferable for practical use, so a refrigerator is required Is.

In Table 3, * 0.3 to 1.5 μm in the column of wear resistance is based on the wear depth shown in FIG.

[0049]

[Table 3] Further, a cylinder block of an actual machine is formed in the same form as the test piece of Test Example 7 in the form shown in FIG. Bore honing was performed with a grindstone and the tool life was tested. The results are shown in the tool life column of Table 3. This tool life is equivalent to cast iron, that is, cast iron (F
It was as good as bore honing the C23) cylinder block. The conditions for the bore honing are as follows: the whetstone speed is 39 rpm (rotation), 16 m /
min (reciprocating stroke), grindstone expansion pressure 7 to 10 kg
/ Cm ² , and the cross rich angle is 45 °.

Further, using an actual cylinder block having the same configuration as that of Comparative Example 3, bore honing was similarly performed on the alumite layer of the bore of the cylinder block with a grindstone, and the tool life was tested. In this case, the tool life was short and inferior. As described above, according to the material of the present invention, abrasion resistance and seizure resistance are improved, and thus scuffing resistance is also improved. ○ The relationship between the pretreatment performed before iron plating and the adhesion of the iron plating layer was tested.

In this test, as Test Example 8, a cylinder block of an actual machine configured as shown in FIG. 2 was used as a test piece. The conditions of this test piece are based on the above-mentioned Example 1.
And using this test piece, diameter 87.5 mm, height 14
Boring the iron plating layer 4 with a cut amount of 0.15 mm in a 0 mm bore, and further honing the iron plating layer 4 partitioning the inner peripheral surface of the bore with a grindstone. I checked.

Further, as Test Example 9, a model test piece 77 was formed in the composition form according to Test Example 8 as schematically shown in FIG. Then, the steel transmission tool 79 (JIS S4) is attached to the iron plating layer 4 of the model test piece 77 via the adhesive layer 78.
5C) and bond the model test piece 77 to the jig 80,
While sandwiched by 81, the transmission tool 79 was pressed by the descending punch 82 to apply a shear load to the iron-plated portion, and the load when peeled off was evaluated as the adhesion force.

Further, as Comparative Example 4, a cylinder block in which the composite material layer 2 was subjected to double zinc substitution treatment without being subjected to etching treatment, and an iron plating layer was laminated by electroplating on the double zinc substitution treated surface was used as a test piece. Boring and honing were performed in the same manner, and the occurrence of peeling of the iron-plated portion was investigated. Further, as Comparative Example 5, a model test piece 77 shown in FIG. 6 was formed in the composition form according to Comparative Example 4, and a shear load was applied to this as well as shown in FIG. I checked the situation.

Further, as Comparative Example 6, a double zinc substitution treatment was performed on the surface layer portion of the ADC12 alloy containing no reinforcing fiber or composite material layer 2, and then a cylinder block having an iron plating layer laminated was used as a test piece, and similarly drilled. Then, honing was performed to examine the occurrence of peeling on the iron-plated part. As Comparative Example 7, the same composition form as in Comparative Example 6 was used.
The model test piece 77 shown in FIG.

Further, as Comparative Example 8, a cylinder block in which a surface layer portion of ADC12 alloy containing no reinforcing fiber or composite material layer 2 was pretreated by alkaline surpass treatment and then an iron plating layer was laminated by electroplating was used as a test piece. The boring process and the honing process were performed in the same manner as described above, and the occurrence of peeling of the iron-plated portion was examined. As Comparative Example 9, a model test piece 77 was formed in the same composition form as in Comparative Example 8, and this was also subjected to the shear test.

The above-mentioned test results, in other words, the test results of the adhesion force of the iron-plated portion when the cylinder block was subjected to boring and honing, and the iron-plated portion when a shear load was applied to the model test piece 77. The adhesion test results were taken into consideration comprehensively. The result is shown in FIG. 7. According to FIG. 7, the adhesive force according to Comparative Examples 4 and 5 subjected to double zinc substitution treatment was set to 1, and the adhesive force of each example was shown by relative evaluation.

As shown in FIG. 7, according to the test examples 8 and 9 of the material of the present invention, the ratio of the adhesive force was about 2.
It can be seen that the adhesion of the iron-plated part has dramatically increased. On the other hand, according to Comparative Examples 4 to 9, the ratio of the adhesive force is about 1 or less than 1, and the adhesive force is not sufficient. The double zinc substitution treatment described above is a pretreatment for increasing the adhesion of the plating that is generally used when plating the iron and aluminum alloys, and after removing the surface oxide film of the aluminum alloy, zinc is applied to the surface. This is a method of applying a thin film (of the order of angstrom) to make the surface potential uniform and then performing the plating treatment. In this example, based on the usual conditions for an aluminum alloy, solvent degreasing → alkaline degreasing → water washing → alkaline etching treatment → water washing → pickling → zinc substitution treatment → water washing → nitric acid washing → water washing → zinc substitution treatment for the aluminum alloy. I went in order.

The above-mentioned alkaline surpass treatment is a treatment for removing the surface oxide film of the aluminum alloy and activating the surface. In this example, the solution (composition: NaOH: 10 g / liter and Na ₃ P0 ₄ : 100 g / (A mixed solution with liter) was used and the aluminum alloy was immersed in the solution for about 1 minute. ○ The relationship between the etching depth and the adhesion of the iron-plated part was investigated. The evaluation of the adhesive strength was the same as that shown in FIG.
This test was based on the test piece according to Test Example 7 shown in Table 3.

The results are shown in FIG. The horizontal axis of FIG. 8 represents the etching depth, and the vertical axis represents the adhesion of the iron-plated portion. The vertical axis of FIG. 8 shows the relative ratio when the adhesion of the iron-plated portion is set to 1 when the etching depth is 0.2 μm. As can be understood from the characteristic line of FIG. 8, there is a relative relationship between the etching depth and the adhesive force, and it is understood that as the etching depth increases, the ratio of the adhesive force of the iron-plated portion increases. However, if the etching depth is excessive, the reinforcing fibers are likely to float during the etching process, which causes problems such as the falling of the reinforcing fibers. Therefore, when the above-mentioned reinforcing fibers are used, the upper limit of the etching depth is preferably about 20 μm, that is, the etching depth is 0.2 μm.
˜20 μm, preferably 0.5 to 10 μm.

According to Comparative Example 3 shown in Table 3, the adhesion ratio of the alumite layer was as low as about 0.8. ○ The amount of oil rise was tested. When a cavity is formed on the inner peripheral surface of the cylinder bore, the engine oil accumulates in the cavity of the cavity during driving of the engine to increase the amount of oil rising and increase the amount of oil consumption. Therefore, the amount of oil rising was tested for the purpose of investigating the condition of the generation of cavities on the inner peripheral surface of the cylinder bore.

In this test, as Test Example 10, a cylinder block based on the conditions shown in Example 1 and having the form shown in FIG. 2 was used as a test piece. Then, a cylinder block test piece was incorporated in an in-line four-cylinder 1800 cc gasoline engine, and the oil rise amount was calculated based on the oil supplement amount (g / hr) when the oil level was kept constant by bench evaluation. . The gasoline engine driving conditions are as follows: engine speed 5200 rpm, full load,
The oil temperature is 120 ° C and the cooling water temperature is 100 ° C.

In this oil rising test, as Comparative Example 10, a cylinder block made of cast iron (FC23) having no reinforcing fiber, composite material layer 2 or iron plating layer was used as a test piece. Furthermore, as Comparative Example 11, an aluminum alloy (A
DC12 equivalent material) and cast on the surface of the bore of Ni-Si
A cylinder block in which a C plating layer (plating thickness: 20 μm, average particle diameter of SiC particles: 1 μm) was laminated was used as a test piece.

In this oil rising test, since the same parts are used in all of the examples and the comparative examples except the cylinder block, the difference in the oil replenishment amount can be grasped as the difference in the oil rising amount. The test results are shown in FIG. In this case, the oil rising amount in Comparative Example 10 (FC23 equivalent material) is 1
Was set as the relative evaluation. As shown in FIG. 9, in Comparative Example 11, the oil rising amount was as large as 2.

According to Test Example 10 which is a material of the present invention, the oil rise amount is significantly reduced to about 0.5, which is advantageous for reducing the oil consumption amount. It is presumed that this is because the gap between the fibers of the fiber molded body was appropriate and there was almost no porosity on the surface of the cylinder bore, so the amount of oil rise was reduced. In Comparative Example 11, many porosity was found near the bore. In Test Example 10 and Comparative Example 10, there were almost no cavities near the bore. In Test Example 10, it is presumed to be due to the gas and air blocking effect of the fiber molded body. ○ A noise test was conducted.

When the cylinder block is made of an aluminum alloy, the elastic modulus and rigidity are lower than that of the cast iron cylinder block, so that the clearance between the inner peripheral surface of the bore and the outer peripheral surface of the piston tends to increase, and noise is generated. It tends to increase.
In this noise test, as Test Example 11, a cylinder block based on the conditions shown in the above-described Example 1 and having the form shown in FIG. 2 is used as a test piece. Then, the cylinder block was installed in an in-line 4-cylinder 1800 cc gasoline engine, and the noise level was measured at 1 m above, to the right, to the left, to the bottom, and to the front of the engine when operating at full load by bench evaluation. Then, the average value was compared.

As Comparative Example 12, a cylinder block cast from a material equivalent to ADC12 was used as a test piece. As Comparative Example 13, AA standard (American Aluminum Association standard)
A cylinder block cast from a material corresponding to A390 (Si: 17%) was used as a test piece. As Comparative Example 14, FC
A cylinder block cast from a material equivalent to 23 was used as a test piece. Comparative Examples 12 to 14 do not contain the reinforcing fiber, the iron plating layer and the alumite layer.

The test results are shown in FIG. As shown in FIG. 10, the result of the noise level of Comparative Example 14 relating to the conventional FC23 was set to 0 as a reference value. According to the comparative example 12 in which the cylinder block is formed by the ADC 12, it is increased by 0.6 dB as compared with the reference value. According to the comparative example 13, it was increased by 0.4 dB as compared with the reference value. However, according to Test Example 11 corresponding to the material of the present invention, 0.2d compared with the reference value
Only the increase of B, less than Comparative Examples 12 and 14, the noise characteristics are close to the FC23 cylinder block,
It can be seen that the material of the present invention is advantageous in terms of noise control. It is assumed that the composite material layer 2 and the iron plating layer 4 increased the elastic modulus and ensured the rigidity.

(Other Examples) In the above-mentioned embodiment, the structure is such that the composite material layer 2, the mixed layer 3 and the iron plating layer 4 are laminated on the aluminum alloy layer 1 which is the main body of the member, but it is not limited to this. No, the aluminum alloy layer 1 is not provided, and the composite material layer 2
May be the main body of the member. Also in this case, the mixed layer 3 and the iron plating layer 4 are sequentially laminated on the composite material layer 2.

[Brief description of drawings]

FIG. 1 is a configuration diagram schematically showing a cross section of a metal-based composite material according to an example.

FIG. 2 is a configuration diagram of a main part applied to a cylinder block.

FIG. 3 is a configuration diagram schematically showing an abrasion resistance test.

FIG. 4 is a graph showing wear depth test results.

FIG. 5 is a configuration diagram schematically showing a seizure resistance test.

FIG. 6 is a configuration diagram schematically showing a shear test.

FIG. 7 is a graph showing test results of adhesion.

FIG. 8 is a graph showing the relationship between the adhesion ratio and the etching depth.

FIG. 9 is a graph showing the test results of the amount of oil rising.

FIG. 10 is a graph showing test results of a noise test.

[Explanation of symbols]

In the figure, 1 is an aluminum alloy layer, 2 is a composite material layer, 2c is a reinforcing fiber, 3 is a mixed layer, and 4 is an iron plating layer.

Claims (2)

[Claims] 1. A composite material layer comprising an aluminum alloy matrix and a reinforcing fiber embedded in the matrix, a reinforcing fiber laminated on the composite material layer and protruding from the composite material layer, and an iron-based plated portion. A metal-based composite material, comprising: a mixed layer in which is mixed, and an iron-based plated portion of the mixed layer, which is laminated on the mixed layer and an iron-based plated layer of the same system. 2. A member having a composite material layer comprising an aluminum alloy matrix and reinforcing fibers embedded in the matrix is used, and the surface layer portion of the composite material layer of the member is subjected to etching treatment to obtain the composite material. Performing a step of exposing a part of the reinforcing fibers constituting the layer, and a step of performing an iron-based plating treatment on the surface layer portion of the composite material layer in which the reinforcing fibers are exposed and laminating an iron-based plated layer. A method for producing a characteristic metal-based composite material.