JP2001011556A - Sliding member - Google Patents

Abstract

(57) [Problem] To provide a sliding member excellent in wear resistance and seizure resistance in both an aluminum alloy member and a partner member sliding with the aluminum alloy member. SOLUTION: In weight%, Si: 14.5 to 16.5.
%, Cu: 3.0 to 4.0%, Mg: 0.55 to 0.9
0%, Mn: 0.40 to 0.60%, Cr: 0.05 to
0.30%, Ti: 0.05 to 0.15%, P: 0.0
3-0.05%, Fe: 0.7-1.2%, Zn: 1.
0% or less, Ni: 0.3% or less, Sn: 0.3% or less, primary component Si and Al-Si-Fe- having an average particle diameter of 3 to 10 µm, having a balance of Al and impurities. M
An aluminum alloy member in which an n-Cr based intermetallic compound is crystallized, and a particle dispersion composite plating including a plating matrix composed of Ni, P, and Co and including dispersed particles composed of at least one of hexagonal boron nitride and silicon nitride. A sliding member combined with a mating member was used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aluminum alloy member in which fine primary crystal Si and an Al—Si—Fe—Mn—Cr intermetallic compound are crystallized, and an Ni, P, Co
Wear resistance of both sliding members by combining a plating matrix composed of a hexagonal boron nitride and a particle-dispersed composite plating mating member containing dispersed particles composed of at least one of silicon nitride and silicon nitride. And a sliding member having improved seizure resistance during sliding.

[0002]

2. Description of the Related Art In order to improve fuel efficiency and exercise performance, weight reduction of automobile parts has been continuously promoted. One of the measures is to reduce weight by replacing materials. Material replacement from conventional iron to light metal, such as aluminum, having a lower specific gravity is actively performed.

[0003] Cylinder blocks made of aluminum alloys have already become widespread in automobile internal combustion engines. However, cast iron bores are generally used for cylinder bores requiring wear resistance and seizure resistance. However, in order to further reduce the weight of parts, in some cases, the bore material itself is made of an aluminum alloy with a component different from that of the cylinder material,
In addition, there have been cases where the cylinder block material is used as it is.

[0004] Normally, when replacing the material of the cylinder bore from cast iron to an aluminum alloy, a surface treatment such as plating or thermal spraying is performed on the aluminum alloy or a structure containing primary crystal Si and dispersion strengthened particles is used. Measures have been taken to improve wear resistance and seizure resistance.

Japanese Patent Publication Nos. 3-37028 and 9-42447, which disclose a sliding member in which a combination of an aluminum alloy and a particle-dispersed composite plating are disclosed, are related patent publications.

Among them, Japanese Patent Publication No. 3-37028 discloses a combination of a hypereutectic Al-Si alloy cylinder and a Ni-P or Ni-P-Co composite plating in which silicon nitride particles are dispersed. Regulations.

The latter Japanese Patent Application Laid-Open No. 9-42447 specifies a combination of an aluminum alloy having a Si content of 7 to 30% by weight and a Ni-P composite plating containing a dispersing material such as boron nitride. ing.

According to these publications, wear of both aluminum alloys can be suppressed by using a sliding member in which a particle-dispersed composite plating mainly composed of Ni and P is used as a mating material. .

[0009]

However, these publications relate to the specification of a wide range of aluminum alloys, and in the embodiments described in the publications, Japanese Patent Publication No. 3-37028 discloses the former. In the case of A390
It is considered to be an aluminum alloy by gravity casting or low pressure casting in that the alloy is evaluated. Since the A390 alloy has a large content of Si, the grain size of primary crystal Si and the content of Si are significantly different from those according to the present invention. .

[0010] The amount of Si contained in the aluminum alloy corresponds to the amount of primary crystal Si which greatly affects the wear characteristics.
It has a significant effect on wear and seizure characteristics. Similarly, in the latter JP-A-9-42447, the example here is an aluminum alloy of 18% by weight of Si, and the amount of primary crystal Si is different from that according to the present invention. The crystallization amount of primary Si which greatly contributes also differs.

[0013] Primary crystal Si is added by die casting high pressure casting method.
Combination of cylinder bore and piston ring using aluminum alloy refined to 10 μm,
In particular, there has been no example of an invention that focuses on the surface properties including the state of the primary crystal Si and the surface treatment of the counterpart material.

An object to be solved by the present invention is to provide an aluminum alloy member produced by a die-casting method which has a low Si content for improving machinability and which has high productivity. Another object of the present invention is to improve the abrasion resistance and seizure resistance of both members.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides a sliding member having excellent wear resistance and further improved seizure resistance in mutually sliding members. It is intended to be.

[0014]

According to a first aspect of the present invention, there is provided a sliding member comprising:
14.5 to 16.5%, Cu: 3.0 to 4.0%, M
g: 0.55 to 0.90%, Mn: 0.40 to 0.60
%, Cr: 0.05 to 0.30%, Ti: 0.05 to
0.15%, P: 0.03 to 0.05%, Fe: 0.7
１．２1.2%, Zn: 1.0% or less, Ni: 0.3% or less, Sn: 0.3% or less, the composition of the balance of Al and impurities, and the average particle size of 3 to 10 μm. An aluminum alloy member in which primary crystal Si and an Al-Si-Fe-Mn-Cr-based intermetallic compound are crystallized, and Ni, P, Co
And a particle-dispersed composite plating mating member containing dispersed particles composed of at least one of hexagonal boron nitride and silicon nitride.

Further, in the sliding member according to the present invention, as described in claim 2, the aluminum alloy member is firstly crystallized from the surface of the aluminum alloy member by polishing such as mechanical polishing, electrolytic polishing, and chemical polishing. Si is 0.3-1.
Raised 5 μm and surface roughness Ra: 0.1 to 0.5
μm.

Similarly, in the sliding member according to the present invention, as described in claim 3, the crossing angle of the processing flaw of the processing of the aluminum alloy member in the direction perpendicular to the sliding direction is 25. Ra has a cross-hatched stitch of ~ 55 ° and the surface roughness measured in the sliding direction is Ra:
It can be 0.1 to 0.5 μm.

Similarly, in the sliding member according to the present invention, as described in claim 4, the matrix composition of the particle-dispersed composite plating counterpart member is P: 0.2 to 10%,
Co: 10 to 40%, with the balance being Ni and impurities.

[0018] Similarly, in the sliding member according to the present invention, as described in claim 5, the mating member for particle-dispersed composite plating, wherein the base material is any one of carbon steel, cast iron and stainless steel. It can be.

Similarly, in the sliding member according to the present invention, the average particle size of the dispersed particles is 0.5 to 1 with respect to the particle-dispersed composite plating counterpart member.
It may contain dispersed particles of at least one of hexagonal boron nitride and silicon nitride having a thickness of 0 μm.

Similarly, in the sliding member according to the present invention, as described in claim 7, with respect to the particle-dispersed composite plating mating member, 5 to 5 particles dispersed in hexagonal boron nitride as a solid lubricant are used. 10% by area can be dispersed.

Similarly, in the sliding member according to the present invention, the particle-dispersed composite plating counterpart member is provided with a dispersed particle made of silicon nitride, which is a high-strength material, in an area of 5 to 30 areas. % Dispersion.

Similarly, in the sliding member according to the present invention, as described in claim 9, the aluminum alloy member is a cylinder bore of an internal combustion engine, and the particle dispersion composite plating counterpart member is a piston top ring and a second ring. Can be used.

[0023] Similarly, in the sliding member according to the present invention, the aluminum alloy member is a cylinder bore of an internal combustion engine, and the particle dispersed composite plating mating member is an oil ring. can do.

Similarly, in the sliding member according to the present invention, as described in claim 11, the partner member for particle-dispersed composite plating is a piston top ring, a second ring, or an oil ring. Above, one selected from molybdenum disulfide, graphite, antimony trioxide, and polytetrafluoroethylene
A fired film having a matrix containing a resin containing at least one kind of particles can be formed.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the conventional invention which is a combination of a hypereutectic aluminum alloy and a surface treatment, the composition of the aluminum alloy is often set in a wide range, and the casting is an important factor in the wear characteristics of the aluminum alloy. There are very few examples that include provisions on manufacturing methods such as the above and surface finishing methods. For example, according to the embodiment of the prior art invention described above, gravity casting or low pressure casting,
Alternatively, the effect of the present invention is exhibited only in an aluminum alloy having a composition in which the Si content is higher than that of the present invention, and does not necessarily indicate the effectiveness of the invention for a wide range of aluminum alloys.

In the present invention, attention is paid to primary crystal Si having a small particle size obtained by high-pressure casting such as a die-casting method, and the surface properties of an aluminum alloy, the components of a mating member, the type of a dispersing material, the sliding conditions, etc. In the conventional invention, such a consideration has not been made so far. Furthermore, according to the experimental results of various materials combinations over a wide range of the present inventors, the wear and seizure of the aluminum alloy by the die-casting method are simply described as follows.
Even in combination with a mating member that has been subjected to a composite plating surface treatment according to the invention described in the conventional patent publication, it may not always be possible to obtain the expected wear reduction effect or anti-seizure improvement effect. know.

The aluminum alloy used in the present invention is:
The amount of Si contained is 14.5 to 16.5% by weight, and the primary crystal Si is crystallized by the die casting method in an average of 4 to 6 area% by area ratio depending on the image processing conditions.
The fine crystals having an average particle size of 3 to 10 μm are obtained. This is because the amount of Si is smaller than that of the A390 alloy referred to as the hypereutectic aluminum alloy in the above-mentioned prior art, etc., so that the castability is greatly improved due to a decrease in the temperature of the molten metal,
Further, since the amount of primary crystal Si is greatly reduced, the machinability during processing is significantly improved. However, the hardness of primary crystal Si is H
Since it is also a strengthening particle that greatly exceeds v1000 and is effective in improving the wear resistance of the aluminum alloy, in the aluminum alloy defined in the present invention, an intermetallic compound is precipitated by adding some other elements to form a primary crystal. The configuration is such that the shortage of the amount of Si is complemented.

That is, in the aluminum alloy used in the present invention, Si: 14.5 to 16.5% by weight, C:
u: 3.0 to 4.0%, Mg: 0.55 to 0.90%,
Mn: 0.40 to 0.60%, Cr: 0.05 to 0.3
0%, Ti: 0.05 to 0.15%, P: 0.03 to
0.05%, Fe: 0.7-1.2%, Zn: 1.0%
Hereafter, primary crystal Si and Al—Si—Fe—Mn containing 0.3% or less of Ni and 0.3% or less of Sn, having a balance of Al and impurities, and having an average particle size of 3 to 10 μm.
-It was assumed that a Cr-based intermetallic compound was crystallized.

With respect to the aluminum alloy (member) formed by the die-casting method having such a component composition, the protruding state of primary crystal Si on the sliding surface, the surface roughness, and the processing pattern, and the mating sliding member corresponding thereto. By defining the material of the surface treatment, the components of the composite dispersion plating, which is the surface treatment, and the material, shape and amount of dispersion of the dispersed particles, it is possible to significantly reduce the amount of wear of both and significantly improve the seizure resistance. It is an object of the invention.

The structure of the aluminum alloy, the amount of primary crystal Si,
By conducting a wide range of friction tests combining various conditions such as the protruding state of primary crystal Si, the texture, the surface roughness, and the surface treatment material of the mating member, the conventional technology is regarded as an important factor affecting wear and seizure. It has been found that there are some factors that are not mentioned above, and various experiments have revealed that the characteristics required for the sliding partner differ depending on the combination of these factors.

That is, in the sliding member according to the present invention, Si: 14.5 to 16.5% and Cu: 3.0 to 3.0% by weight.
4.0%, Mg: 0.55 to 0.90%, Mn: 0.4
0 to 0.60%, Cr: 0.05 to 0.30%, Ti:
0.05 to 0.15%, P: 0.03 to 0.05%, F
e: 0.7 to 1.2%, Zn: 1.0% or less, Ni:
Primary crystal Si and Al-Si-Fe-Mn-Cr-based metal containing 0.3% or less, Sn: 0.3% or less, having a balance of Al and impurities, and having an average particle size of 3 to 10 m. Aluminum alloy member in which intermetallic compound is crystallized, and N
An aluminum alloy, wherein a plating matrix composed of i, P, and Co is combined with a particle-dispersed composite plating counterpart member containing dispersed particles composed of at least one of hexagonal boron nitride and silicon nitride. In addition, the composition and composition of the above-mentioned components, the component composition of the particle-dispersed composite plating to be combined as the mating member, and the type of the dispersing material are specified.

The aluminum alloy specified here is Si
The amount is appropriately controlled as 14.5 to 16.5%, and instead, an alloy component is added so as to crystallize an Al-Si-Fe-Mn-Cr-based intermetallic compound. This is a die-cast alloy that has significantly reduced the machinability of the eutectic alloy and at the same time reduced wear resistance. The feature of this alloy is that the crystallization amount of primary crystal Si is smaller than that of a hypereutectic alloy such as A390 and the grain size is also small, so that a mating member suitable for this is necessary.

Since the aluminum alloy specified in the present invention contains hard primary crystal Si, the mating member is required to have wear resistance. Therefore, it is specified that silicon nitride particles having an effect of remarkably improving plating hardness and hexagonal boron nitride particles effective for reducing a frictional force at a sliding portion are included as a dispersing material. Further, Ni-P-Co containing Co, which is effective for improving heat resistance, is defined as a plating matrix. This is because the effect of suppressing deterioration of wear resistance due to heat was recognized.

In the sliding member according to the present invention, the aluminum alloy member contains 0.1% primary crystal Si from the surface of the aluminum alloy member by polishing such as mechanical polishing, electrolytic polishing, and chemical polishing.
Protrudes 3 to 1.5 μm and has a surface roughness Ra: 0.1
０．５0.5 μm as appropriate. In order to improve the wear resistance of the aluminum alloy, only the primary crystal Si exposed on the sliding surface is subjected to mechanical polishing, electrolytic polishing, chemical polishing, or other polishing. It is also desirable that a substance mainly composed of the α-phase is projected from the surface.

According to this, the lubricating state is improved by the action of retaining oil between the protruding primary crystal Si particles, and the load generated by the primary crystal Si as hard particles on the sliding surface is preferentially reduced. By sharing, the wear amount of the entire alloy can be suppressed.
The protruding height of the primary crystal Si is determined by the grain size of the primary crystal Si crystallized in the aluminum alloy. If the protruding amount is low, the effect is small, and if it is too high, it tends to fall off the sliding surface and abrasive wear is reduced. Cause. Since the average grain size of primary crystal Si of the aluminum alloy used in the present invention is 3 to 10 μm, the maximum grain size is 1.5 times or less of the minimum average grain size.
μm or less, and it is desirable that the projection amount be at least 0.3 μm or more. The surface roughness is uniquely determined from the protrusion amount, and is 0.1 to 0.5 μm in the range of the protrusion height of the primary crystal Si described above.

At this time, the intermetallic compound, which is another important factor for securing the wear resistance of the aluminum alloy used in the present invention, is, like the primary crystal Si, smaller than the α phase of aluminum as the matrix. Because it is hard, it is in a state protruding from the surface. However, if the protrusion amount is defined by the primary crystal Si, the protruding state of the intermetallic compound is uniquely determined. Therefore, it is not necessary to independently define the height of the protrusion amount of the intermetallic compound.

In the sliding member according to the present invention, the aluminum alloy member is provided with a cross hatch stitch where the crossing angle of the processing scratch is 25 to 55 ° in the direction perpendicular to the sliding direction and also in the sliding direction. The surface roughness measured in the direction is R
a: It can be 0.1 to 0.5 μm. That is, as another method for improving the wear resistance of an aluminum alloy, there is a cross hatching process which has been used in a conventional cast iron bore of an engine as described herein. And since the direction of the processing line on the sliding surface intersects the sliding direction at a certain angle, it is possible to obtain an oil retaining effect by the processing groove on the sliding surface, and to supply a small amount of lubricating oil. It is effective in reducing the amount of wear when used for The cross angle of the cross hatching defined here is a value obtained by modifying the actual measurement value of the conventional cast iron bore in consideration of the experimental result of the aluminum alloy cylinder bore, and the cross angle is preferably 25 to 55 °, and The surface roughness is suitably set to 0.1 to 0.5 μm in consideration of the amount of retained oil and the suppression of initial wear.

In the sliding member according to the present invention, the matrix composition of the particle-dispersed composite plating partner member is P: 0.2 to
10%, Co: 10 to 40%, and the balance can be made of Ni and impurities.
Has the effect of increasing the hardness of the plating by heat treatment. If the P content is less than 0.2%, the effect of the thermosetting treatment tends not to be obtained. If the P content exceeds 10%, the hardness increases but the material becomes brittle rather than deteriorates the wear resistance. Also, Co
Is effective in improving the heat resistance, corrosion resistance and compressive fatigue strength of the alloy matrix, but if it is less than 10%, the above effect tends not to be remarkably obtained, and if it exceeds 40%, there is no significant change. The amount of Co is preferably set to 10 to 40%.

In the sliding member according to the present invention, it is preferable that the base material of the particle-dispersed composite plating counterpart material is any one of carbon steel, cast iron and stainless steel. However, if the base material does not have a certain degree of hardness, the plating may peel off without following the deformation of the base material, which may lead to increased wear on the plating side and abrasive wear due to the falling powder.

In the sliding member according to the present invention, the dispersed particles contained in the particle-dispersed composite plating partner member may be made of hexagonal boron nitride or silicon nitride having an average particle size of 0.5 to 10 μm. The particle size of the particles dispersed during plating has an optimum value, which is determined by the friction characteristics and the wear characteristics, respectively. Hexagonal boron nitride is a solid lubricant. To obtain this effect, unless the particle size is as large as 0.5 μm or more to some extent, the slip mechanism in the crystal does not appear and the effect of reducing the friction coefficient is obtained. I can't. Also, 1
When the thickness exceeds 0 μm, the hardness of the entire plating is reduced, and the wear resistance of the plating may be deteriorated. On the other hand, the hardness of silicon nitride is as high as about 2000 in Hv, and if the particle size is less than 0.5 μm, the effect of increasing the hardness of the entire plating cannot be obtained or it is easy to fall off, which causes abrasive wear. It is possible. On the other hand, if it exceeds 10 μm, the aggressiveness to the other party becomes strong, and the wear resistance of the aluminum alloy tends to decrease.

In the sliding member according to the present invention, the hexagonal boron nitride contained in the particle-dispersed composite plating counterpart is preferably dispersed in the plating in an amount of 5 to 10 area%, as in the case of silicon nitride. On the other hand, if the area is 5% by area, the effect as a solid lubricant is hardly obtained, and if it exceeds 10% by area, the hardness of the entire plating tends to decrease.

In the sliding member according to the present invention, the amount of silicon nitride contained in the particle-dispersed composite plating counterpart in the plating is preferably 5 to 30% by area. Tends to be unable to obtain the effect of
If the area% is exceeded, the aggressiveness of the opponent becomes stronger, so that the abrasion of the aluminum alloy member tends to increase.

In the sliding member according to the present invention, it is possible to consider various aspects in the combination and application of the aluminum alloy member subjected to the finish processing for protruding primary crystal Si in the aluminum alloy and the counterpart member. it can.
And in the aluminum alloy by the die casting method,
Since the primary Si particles that are key are smaller than those of low-pressure cast materials, it is important to ensure that the primary Si particles that protrude during sliding do not fall off in order to ensure the wear resistance of the aluminum alloy. is there. Therefore, as a result of focusing on this point and trying various surface treatments, a remarkable effect was obtained by Ni-P-Co plating in which hexagonal boron nitride (hBN) as a solid lubricant was dispersed. The reason for this is that the inclusion of a solid lubricant in the plating causes the shear force at the solid contact portion generated when primary crystal Si in the aluminum alloy and projections on the plating surface of the mating member interfere with each other during sliding. This is probably because the inclusion of the lubricant greatly reduced the amount of primary crystal Si that protruded from the sliding surface. The reduction in the shearing force at the contact point is also effective in suppressing the wear of the plating of the mating member.

As an application of these combinations to an engine part, a cylinder bore of an aluminum alloy which is required to have abrasion resistance and seizure resistance, and a piston top ring and a second ring which are subjected to particle dispersion composite plating can be provided. . The sliding here involves a problem of wear at the top dead center on the aluminum alloy cylinder bore side, and requires a mating material that has low mating aggressiveness and also has some wear resistance.

The sliding conditions are as follows: the maximum surface pressure is 20 MPa or less, which is lower than the plastic deformation range of the aluminum alloy, and the lubricating oil amount is small and the sliding speed fluctuates in a large range. It is thought that improvement focusing on how to maintain the value is effective. For this reason, in combination with the aluminum alloy cylinder bore on the surface, the piston top ring and the second ring, which have been subjected to particle dispersion composite plating in which hexagonal boron nitride is dispersed as a solid lubricant, are used as mating members, and the effect of the present invention is achieved. Is obtained.

In addition, when a cross-hatched aluminum alloy member is used in combination with its mating member, when the cross-hatching is performed, the wear resistance of the aluminum alloy is greatly reduced by the lubricating oil held in the processing grooves. Be improved. On the other hand, the primary crystal Si in the surface layer has a high rate of crushing during processing, and it is considered that the role of the primary crystal Si in the initial wear resistance is not so large. Rather, since the crushed powder of primary crystal Si remaining on the surface of the aluminum alloy may fall off during the initial sliding, the mating member is also required to have wear resistance. The particle-dispersed composite plating in which hexagonal boron nitride, which is a solid lubricant, is dispersed, has a low hardness but has a low coefficient of friction generated in a sliding portion, so that it is sufficient for a load on a top ring or a second ring. Shows wear resistance. In the case of the particle-dispersed composite plating in which silicon nitride, which is hard particles, is dispersed, the hardness is greatly improved, so that more excellent wear resistance is exhibited. Furthermore, when the aluminum alloy is cross-hatched, the effect of retaining the lubricating oil can be further expected, so that the aggression by silicon nitride is absorbed to some extent. However, in the particle-dispersed composite plating in which silicon carbide having a higher hardness is dispersed, the particles have excellent wear resistance, but the shape of the particles is sharp.
The aluminum alloy side may be significantly worn.
For this reason, in combination with an aluminum alloy cylinder bore having a cross hatched portion, a piston top ring and a second ring of particle-dispersed composite plating in which hexagonal boron nitride and / or silicon nitride are dispersed are used as mating members. The effect is obtained.

Further, a cylinder bore is formed of an aluminum alloy subjected to a finish processing for protruding primary crystal Si or an aluminum alloy having a surface cross-hatched, and an oil ring serving as a mating member is made of a particle-dispersed composite in which silicon nitride is dispersed. There is also a combination of plating. As a result of a close examination of the wear mode of the oil ring, it was clarified by experiments that the tendency of wear of the piston top ring and the second ring was different. Generally, the wear of the cylinder bore is greatest near the top dead center of the top ring, followed by the return point of the second ring, and the least return point of the oil ring. This is because the temperature and the surface pressure at the time of explosion are low, and the amount of lubricating oil is abundant.

On the other hand, the oil ring has the highest tension as compared with the other rings, and the cylinder bore is in contact with the two upper and lower rail side surfaces constituting the oil ring, and the curvature here is the largest among the piston rings. Due to its small size, the surface pressure at the contact point is the highest in all processes except the time of the explosion. In fact, even in engine endurance tests using a hypereutectic aluminum alloy as a cylinder bore, this tendency appears greatly,
It has been confirmed that the oil ring wears the most.

Therefore, the wear resistance of the particle-dispersed composite plating in which hexagonal boron nitride having a low hardness is dispersed is insufficient, and an oil ring provided with the particle-dispersed composite plating in which silicon nitride having a high hardness is dispersed is suitable. ing. In the case of using a particle-dispersed composite plating in which silicon nitride is dispersed,
Experiments have verified that the amount of wear on both the cylinder bore and the oil ring is at a level that does not matter regardless of the shape of the cylinder bore surface.

In the piston ring and the oil ring which are mating members sliding with the cylinder bore which is the aluminum alloy member specified in the present invention, abrasion resistance in sliding with the cylinder bore is provided on the ring side particle dispersion composite plating. It is also desirable to apply a resin fired film containing a solid lubricant such as molybdenum disulfide for improving seizure resistance. In sliding with the aluminum alloy member according to the present invention, the most important factor affecting seizure resistance and wear resistance is primary crystal Si in the aluminum alloy. The fired film containing the solid lubricant, falling off powder generated by the primary crystal Si particles remaining on the surface while being crushed during processing and falling off at the beginning of sliding,
The point of suppressing the aggressiveness of the primary crystal Si particles that have protruded too much,
Further, it is effective to promote uniform start-up in the ring and the bore, and to suppress generation of secondary falling off of primary crystal Si due to one-sided contact. Examples of the solid lubricant for obtaining such an effect include molybdenum disulfide, graphite (graphite), antimony trioxide, polytetrafluoroethylene (PTFE), and the like.

Although the combination of the aluminum alloy member specified by the present invention and the mating member sliding with the aluminum alloy member has been described above, the aluminum alloy member according to the present invention has a wear resistance such as A390 which is found in a conventional patent publication. Compared with aluminum alloys, the Si content is lower, the machinability can be improved, and the productivity can be improved due to the die-casting method, and the cost can be reduced. Thus, a sliding member having excellent wear resistance and seizure resistance can be obtained.

[0052]

According to the sliding member of the present invention, as described in claim 1, Si: 14.5 to 1% by weight.
6.5%, Cu: 3.0 to 4.0%, Mg: 0.55
0.90%, Mn: 0.40 to 0.60%, Cr: 0.
05 to 0.30%, Ti: 0.05 to 0.15%, P:
0.03 to 0.05%, Fe: 0.7 to 1.2%, Z
n: 1.0% or less, Ni: 0.3% or less, Sn: 0.3
% Of primary crystal Si and Al-Si having a balance of Al and impurities, and having an average particle size of 3 to 10 μm.
-Aluminum alloy member in which an Fe-Mn-Cr-based intermetallic compound is crystallized, and particles containing dispersed particles composed of at least one of hexagonal boron nitride and silicon nitride in a plating matrix composed of Ni, P, and Co Since it is combined with the dispersed composite plating counterpart, the Si content is suppressed, so the machinability is good and the die casting method can be applied, and it has excellent wear resistance and excellent seizure resistance A remarkable effect that an excellent sliding member can be provided is brought about.

And, as described in claim 2,
The aluminum alloy member is subjected to primary crystal S from the surface of the aluminum alloy member by polishing such as mechanical polishing, electrolytic polishing, and chemical polishing.
i protrudes 0.3 to 1.5 μm and the surface roughness is R
a: When the thickness is 0.1 to 0.5 μm, the lubricating state can be favorably maintained by the oil retaining action between the protruding primary crystal Si particles, and the lubrication state is generated on the sliding surface. By giving the load preferentially to the primary crystal Si, a remarkably excellent effect is obtained in that the wear resistance can be improved.

Further, as described in claim 3, the cross-hatched stitch where the crossing angle of the cut of the cut is 25 to 55 ° in the direction perpendicular to the sliding direction with respect to the aluminum alloy member. When the surface roughness measured in the sliding direction is Ra: 0.1 to 0.5 μm, it is possible to obtain an oil retaining effect by the processed grooves on the sliding surface, A remarkable effect that it is possible to improve the wear resistance even when the amount of oil is small is provided.

Still further, as described in claim 4, the matrix composition of the particle-dispersed composite plating partner member is as follows:
By containing 0.2 to 10% of P and 10 to 40% of Co and the balance of Ni and impurities, it is possible to improve the heat resistance, corrosion resistance, and wear resistance of the mating member. Is a great effect.

Further, as set forth in claim 5, the base material of the particle-dispersed composite plating counterpart member is selected from the group consisting of carbon steel, cast iron, and stainless steel, thereby hardening the counterpart member. And the plating can sufficiently follow the deformation of the base material, and a great effect that it is possible to prevent the peeling of the plating layer due to the deformation of the base material is brought about. .

Further, as set forth in claim 6, at least one of hexagonal boron nitride and silicon nitride having an average particle size of dispersed particles of 0.5 to 10 μm is provided for the particle-dispersed composite plating counterpart member. By including the dispersed particles consisting of seeds, it is possible to provide a sliding member that has good wear resistance of itself and low aggression to a counterpart material and has excellent wear resistance. Significant effects are brought about.

Further, as described in claim 7, the particle-dispersed composite plating counterpart member is characterized in that dispersed particles composed of hexagonal boron nitride, which is a solid lubricant, are dispersed by 5 to 10% by area. By doing so, a remarkable effect is obtained that a composite plating counterpart member having excellent self-lubricating properties and low aggression to the aluminum alloy member can be obtained.

Further, as set forth in claim 8, in the particle-dispersed composite plating counterpart member, dispersed particles composed of silicon nitride, which is a high-strength material, are dispersed by 5 to 30 area%. Thereby, a remarkable effect that a composite plating counterpart member having appropriate hardness and excellent abrasion resistance can be obtained can be obtained.

Further, as described in the ninth aspect, the aluminum alloy member is a cylinder bore of an internal combustion engine, and the particle dispersion composite plating counterpart member is a piston top ring and a second ring. A remarkable effect is obtained that a combination of a cylinder and a piston ring of an internal combustion engine having excellent wear resistance and seizure resistance can be used.

Still further, the wear resistance and the wear resistance can be improved by using a combination in which the aluminum alloy member is a cylinder bore of an internal combustion engine and the counterpart member of the particle-dispersed composite plating is an oil ring. A remarkable effect is obtained that a combination of a cylinder and an oil ring of an internal combustion engine having excellent seizure can be used.

Still further, as another aspect of the present invention, the partner member for particle-dispersed composite plating is a piston top ring, a second ring, or an oil ring, and molybdenum disulfide, graphite, Sliding of the piston ring or oil ring with the cylinder bore by forming a fired film with a matrix containing a resin containing at least one particle selected from antimony trioxide and polytetrafluoroethylene. A remarkable effect that it is possible to further improve the wear resistance and the seizure resistance of the surface is provided.

[0063]

Hereinafter, embodiments of the present invention will be described.
It goes without saying that the present invention is not limited to only such an embodiment.

In evaluating the characteristics of the sliding member according to the present invention, the surface finish of the aluminum alloy member, the surface treatment of the mating member, and the type, amount, particle size, etc. of the dispersed particles differ in the case of particle-dispersed composite plating. A plurality of test pieces were prototyped and evaluated by a basic wear test alone.

The effect of the present invention is to reduce the amount of wear and improve the seizure resistance. Therefore, in the evaluation, a wear test for measuring the amount of wear under a constant load by using a ring / plate type single wear test device. And a scuff test to measure the point where the friction coefficient was unstable or suddenly increased by continuously increasing the load. These evaluation methods are relatively correlated with the evaluation using the actual engine. Also,
The plate specimen contains the primary crystal S
A die-cast alloy having an average particle size of 4 to 6 μm was used. Furthermore, carbon steel was used for the ring as the mating member, and aluminum was used as the comparative material. As the lubricating oil, a commercially available engine oil 5W30SG was used. Details of the combinations tested are shown in Table 1.

[0066]

[Table 1] The conditions of the wear test and the scuff test will be described.
All the tests were performed using new test pieces and lubricating oil. The test conditions at this time are shown below.

(1) Reciprocating single wear test Pressing load: 30 kg Contact state: surface contact Ring outer diameter / inner diameter: 26/20 mm Average sliding speed: 0.2 m / s Lubricating oil temperature: 20 ° C. (room temperature) Lubricating oil type : Commercial engine oil, 5W30SG standard Lubrication method: Bathtub type Test time: 20 minutes (2) Reciprocating single scuff test Pressing load: Increase at 10 kgf / min Average sliding speed: 0.2 m / s Temperature at test: 20 ° C ( Lubricating oil type: Commercial engine oil, 5W30SG standard Lubrication method: Apply only to the sliding part of the ring test piece before the test. In addition, a durability test using an actual engine was performed, and the cylinder bore and piston ring specified in the present invention were tested. An evaluation was performed. The conditions of the engine durability test are shown below. At this time, the combination of the tests was different for each of the four cylinders of the engine, and two tests were performed using a cylinder block having primary crystal Si protruding on the bore surface and two cylinder blocks having a cross-hatched bore surface. Was. Table 2 shows each combination.

[0068]

[Table 2] (3) Engine endurance test Engine: In-line 4-cylinder, displacement 1300cc Endurance conditions: 100 hours at 6000 rpm constant Lubricating oil temperature: 110 ° C Lubricating oil type: Commercial engine oil, 5W30SG standard The test results are briefly described below. Table 1 shows the results of the wear test and the scuff test using the simple substance of 1) and (2), classified into Examples and Comparative Examples.
FIGS. 1 and 2 show the results of the engine durability test of (3).

The results of the ring / plate type unit test will be briefly described below.

Examples 1 to 6 shown in Table 1 satisfy the conditions specified in the present invention. According to these, the amount of wear on the ring side and the plate side is suppressed, and high scuffing is generated. Surface pressure was obtained, and it was confirmed that the abrasion resistance and seizure resistance of the aluminum alloy member and its mating member were improved.

In Comparative Examples 1 to 8, there are some items that deviate from the conditions specified in the present invention, and the amount of wear on the ring or plate side is large, or the scuffing surface pressure is lower than that of the Example. Indicated.

Of these, in Comparative Example 1, since the primary crystal Si projection of the aluminum alloy member was as large as 2.3 μm, abrasion due to aggression to the ring side was large, and the primary crystal Si
It is probable that the particles tended to fall off due to the excessively large protrusion amount, and that the abrasive wear of the dropped particles increased the wear of both the ring and the plate.

In Comparative Example 2, since the base material was aluminum, the plating layer on the ring side could not follow the elastic deformation of the ring itself immediately after the start of the test, and peeled off, resulting in abrasive wear and abnormal wear. .

Further, in Comparative Example 3, primary crystal Si on the plate side was used.
It is considered that the oil retention was deteriorated and the scuffing load was low because of little protrusion.

Furthermore, in Comparative Example 4, since the surface treatment of the ring was Cr plating, and the hardness was lower than that of Ni-P-Co plating, it is considered that the amount of wear on the ring side was increased.

Furthermore, in Comparative Example 5, the surface treatment of the ring was performed by nitriding. The surface hardness of the ring greatly exceeded Hv 1000, which was higher than that of Ni-P-Co, which was about Hv 800 to 950. It is probable that the aggressiveness on the ring side was strong, the amount of wear on the plate side increased, and the scuffing surface pressure decreased due to the effects of abrasion powder and the like.

Further, in Comparative Example 6, it is considered that the roughness of the cross hatching was as small as Ra 0.05 μm, and the wear was deteriorated due to the low oil retaining property on the plate alloy side.

Further, in Comparative Example 7, the surface roughness by cross-hatch processing was as large as Ra 1.2 μm, and the surface roughness was large, so that the opponent aggression to the ring side was strong. Since the crushing rate of the primary crystal Si on the surface is very high, it is considered that the primary Si fell off in the initial stage of sliding and caused abrasive wear.

Further, in Comparative Example 8, silicon carbide (SiC), which is hard particles, was dispersed in plating on the ring side. Conceivable.

Further, the engine durability test was performed for 100 hours, and the results of measuring the wear of the cylinder bore and the piston ring after the test are shown in FIGS. 1 and 2. In the combinations of Test Nos. 1 to 8 shown in Table 2, when the combination satisfies the conditions specified in the present invention, the wear amounts of the cylinder bore and the piston ring are both at low levels.

From the above test results, according to the present invention, a combination excellent in wear resistance and seizure resistance can be obtained for an aluminum alloy member excellent in machinability and productivity and a mating member. It has been confirmed that a combination of a cylinder bore and a piston ring to which this is specifically applied can be obtained.

[Brief description of the drawings]

FIG. 1 is a graph showing a top ring wear amount and a bore wear amount among engine durability evaluation results.

FIG. 2 is a graph showing an oil ring wear amount among engine durability evaluation results.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) F16J 1/01 F16J 1/01 (72) Inventor Yutaka Mabuchi Yutaka 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Inside (72) Inventor Masahiko Shiota 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Inside Nissan Motor Co., Ltd. (72) Inventor Masahiko Katsu 2 Takaracho, Kanagawa-ku, Yokohama City, Kanagawa Nissan Motor Co., Ltd. (72 ) Inventor Satoshi Murata 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) 3G024 AA22 FA06 GA06 GA10 GA18 HA00 HA02 HA03 HA07 HA13 3J044 AA02 AA08 BA04 BA10 BB14 BB15 BB26 BB27 BB31 BB37 BC06 BC11 4K020 AA22 AA27 AC06 BB27

Claims (11)

[Claims] 1. Si: 14.5 to 16.5% by weight
%, Cu: 3.0 to 4.0%, Mg: 0.55 to 0.9
0%, Mn: 0.40 to 0.60%, Cr: 0.05 to
0.30%, Ti: 0.05 to 0.15%, P: 0.0
3-0.05%, Fe: 0.7-1.2%, Zn: 1.
0% or less, Ni: 0.3% or less, Sn: 0.3% or less, primary component Si and Al-Si-Fe- having an average particle diameter of 3 to 10 µm, having a balance of Al and impurities. M
An aluminum alloy member in which an n-Cr based intermetallic compound is crystallized, and a particle dispersion composite plating including a plating matrix composed of Ni, P, and Co and including dispersed particles composed of at least one of hexagonal boron nitride and silicon nitride. A sliding member comprising a combination with a mating member. 2. The aluminum alloy member has primary crystal Si projected from the surface of the aluminum alloy member by 0.3 to 1.5 μm by polishing such as mechanical polishing, electrolytic polishing, and chemical polishing, and has a surface roughness of Ra: 0.1. The sliding member according to claim 1, wherein the thickness is 0.5 μm. 3. A crossing angle of a processing flaw of a processing edge of the aluminum alloy member in a direction perpendicular to a sliding direction is 25 to 3.
The sliding member according to claim 1, wherein the sliding member has a cross hatch stitch of 55 ° and has a surface roughness Ra: 0.1 to 0.5 μm measured in the sliding direction. 4. The particle-dispersed composite plating mating member has a matrix composition containing P: 0.2 to 10% and Co: 10 to 40%, the balance being Ni and impurities. The sliding member according to any one of the above. 5. A particle dispersion composite plating partner member,
The sliding member according to any one of claims 1 to 4, wherein the base material is any one of carbon steel, cast iron, and stainless steel. 6. A particle dispersion composite plating partner member,
6. A method according to claim 1, wherein the dispersion particles include at least one of hexagonal boron nitride and silicon nitride having an average particle diameter of 0.5 to 10 [mu] m.
The sliding member according to any one of the above. 7. A particle dispersion composite plating partner member,
Dispersed particles consisting of hexagonal boron nitride as a solid lubricant
The sliding member according to any one of claims 1 to 6, wherein the sliding member is dispersed by 10 to 10 area%. 8. The particle dispersion composite plating partner member,
The sliding member according to any one of claims 1 to 7, wherein dispersed particles composed of silicon nitride, which is a high-strength material, are dispersed in 5 to 30 area%. 9. A combination according to claim 1, wherein the aluminum alloy member is a cylinder bore of an internal combustion engine, and the particle dispersion composite plating counterpart member is a piston top ring and a second ring. Sliding member. 10. A sliding member according to claim 1, wherein the aluminum alloy member is a cylinder bore of an internal combustion engine, and the particle dispersion composite plating counterpart member is an oil ring. 11. A particle dispersion composite plating counterpart is a piston top ring, a second ring or an oil ring, and molybdenum disulfide,
11. A fired film having a matrix containing a resin containing at least one particle selected from graphite, antimony trioxide, and polytetrafluoroethylene is formed. Sliding member.