JPS61171964A - Slidable contact member excellent in wear-proofness - Google Patents

Abstract

PURPOSE:To improve wear-proofness and lubrication performance by dispersing highly rigid material on a cast iron surface on which graphite having self- lubrication is dispersed. CONSTITUTION:Highly rigid wear-proof material 4 are filled in plural concave portions 3 formed by photo etching method on a surface of a cast iron base 1 on which graphite 2 is dispersed. Therefore, graphite 2 having self-lubrication performance and highly rigid water-proof material 4 excellent in wear-proofness are mixed and dispersed on the surface of a slidable contact member. Then, wear-proofness and baking proofness are improved and optimum slidable contact member of high output and high rotation engine is obtained. As the highly rigid wear-proof member is filled in the concave portions formed by photo etching method on the surface of the slidable contact member, better stickness can be obtained and long term use can be made.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sliding contact member having excellent wear resistance and used for the inner circumferential surface of an engine cylinder.

(Prior art) Cast iron materials containing a large amount of graphite as a lubricant, such as alloy cast iron with a flaky graphite structure, are commonly used as sliding contact members that require wear resistance, such as cylinder litchi for automobile engines. As we all know, as engines become more powerful and rotate at higher speeds, the sliding surfaces of cylinders, etc., are exposed to high temperatures and pressures, and as a result, cast iron materials The lubricity of the graphite contained therein alone causes the oil film to run out, resulting in wear.

This causes problems such as seizure and scuffing.

Therefore, as a countermeasure against these problems, it is necessary to provide a plating layer (see Japanese Patent Publication No. 18604/1984) or a sprayed layer of a high-hardness, high-melting-point metal (such as chromium) on the surface of the sliding contact member, or a sprayed ceramic layer. Methods such as providing a steel material or surface hardening the steel material are often used. However, plated layers of hard metals, thermal sprayed layers, or surface-hardened steel materials lack self-lubricating properties, resulting in poor wear resistance. There is a problem in that durability is poor due to poor adhesion with the contact member.

In addition, there are some products in which a composite plating layer is formed on the surface of the sliding contact member by dispersing and eutectoiding hard fine particles or self-lubricating fine particles, but in this case, the composite plating method is complicated and lacks productivity. Contains problems.

Furthermore, there is a method in which silicon carbide is embedded into the surface of the sliding contact member to disperse and strengthen it using a mechanical method, but this method is very complicated and has poor productivity.

(Purpose of the Invention) The present invention has been made in view of the points pointed out in the above-mentioned prior art section, and includes a highly hard substance (i.e., wear-resistant material) dispersed on the surface of cast iron in which self-lubricating graphite is dispersed. The purpose of this is to improve wear resistance and lubricity.

(Means for Achieving the Object) The present invention, as a means for achieving the above object, forms a large number of recesses dispersedly on the surface of cast iron in which graphite is dispersed, and fills the recesses with a hard wear-resistant material (for example, chromium, etc.). By filling the cast iron surface (that is, the sliding surface) with graphite, which has self-lubricating properties, and a hard wear-resistant material with excellent wear resistance, the cast iron surface (that is, the sliding surface) is dispersed and mixed. Note that a plating method, a thermal spraying method, or the like is employed as a method for filling the recess with the hard wear-resistant material.

(Function) In the present invention, the following effects can be obtained by the above means.

In other words, the graphite and hard wear-resistant material dispersed and mixed on the cast iron surface (i.e., the sliding surface) provide wear resistance and seizure resistance (
That is, the lubricity) is significantly improved.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

Sliding member according to this embodiment (for example, cylinder liner)
As shown in FIG. 1, graphite (for example, flake graphite)2.
It is constructed by filling a hard wear-resistant material (for example, chromium, etc.) 4 into a large number of recesses 3, 3, .

In other words, the surface of the sliding member 1-'', the self-lubricating property 2, 6 graphite 2, 2°2, the hard wear-resistant material 4, 4, which has excellent wear resistance, are mixed and dispersed. , a plating method or a thermal spraying method is adopted as a method for filling the hard wear-resistant material 4 into the recesses 3, 3, .

Next, a method for manufacturing this sliding contact member will be described in detail.

As shown in Figure 2, the manufacturing process of the sliding contact member includes a polishing process A.
1 photoetching step B1 wear-resistant material filling step C (specifically, plating step C1 or thermal spraying step C2), photoresist film stripping step and honing step E.

The polishing process A is for reducing the surface roughness of the base material l (for example, a cast iron base material having a flaky graphite structure) as much as possible in order to maintain the processing accuracy of the next process, photoetching, and is given by Ra + axlμ. It is desirable that the surface roughness is as follows.

In the photoetching step B, as shown in FIG. 3, the surface of the substrate 1, which has been degreased and cleaned using an alkaline degreasing solution or an organic solvent, is coated with an ultraviolet-sensitive photoresist 5 (generally a negative resist is used). In the photosensitive agent coating step B, the surface of the photoresist 5 is coated with non-transparent areas 6a, 6a... in a pattern corresponding to the recesses 3.3... (see FIG. 1).
A photomask adhesion step B in which a photomask 6 formed by forming a photomask is brought into close contact with the photomask 6;

7, a developing step B4 in which the unexposed portion 5b that was not irradiated with ultraviolet rays is dissolved and peeled off using a developer, and an etching process is performed on the surface of the base material 1 to remove the exposed portion. and an etching step B in which the portions not covered by 5a are etched to form recesses 3.3.

In the wear-resistant material filling step C, a hard wear-resistant material 4 (for example, Chromium or chromium carbide) is filled by plating or thermal spraying.

Thereafter, after peeling off the resist film 5a, a light honing process is performed to obtain a cast iron surface in which hard wear-resistant materials 4, 4, etc. are dispersed as shown in FIG.

Next, specific examples will be described. A hard 11R resistant material was formed on the surface of the cast iron base material shown in Table 1 below by the above manufacturing method. Comparative example 1.2
A wear test was conducted on the following.

In Example 1 of the present invention, alloyed cast iron having a flaky graphite structure (having the composition shown in Table 1) was used as the cast iron base material, and was processed into a disk-shaped test piece for wear testing under the following conditions. It was manufactured.

(1) Photoetching conditions (a) Photoresist: Use a commercially available negative film resist (resist thickness: 15μ, resolution = 3
0μ).

(b) Photomask: halftone dot pattern obtained by reducing the photo from the enlarged original (halftone diameter = 100μ, area ratio: 1)
0%).

(c) Light source and exposure time: Using a high-pressure mercury lamp (light emission length: 250 ml, lamp output 2000 W),
Exposure for 7 seconds.

(d) Development conditions: 1,1,1 trichloroethane was used as the developer, and the phenomenon was observed using a one-way spray method for 2 minutes.

(e) Resist stripping liquid: ethylene chloride.

(f) Etching conditions: Electrolytic etching for 2 minutes at a current density of 5 A/cm' in an electrolytic solution of 15 wt% sodium nitrate aqueous solution (room temperature). The size of the recess after etching,
Approximately 120μ in diameter and 2θ~25μ in depth.

(n) Plating conditions (a) Plating type: Hard chrome plating (normal Sargent type plating used).

(b) Electrolysis conditions: Bath temperature: 50°C, current density: 50A
/ds”. Pre-described invention example 2
The same alloy cast iron as in Example 1 of the present invention was processed into a disc-shaped test piece, and it was manufactured under the following conditions.

(1) Photoetching conditions This is the same as Example 1 of the present invention.

(n) Thermal spraying conditions (a) Thermal spraying method: Plasma spraying method (using a commercially available plasma spraying machine).

(b) Thermal spray powder...Chromium carbide powder for thermal spraying (particle size:
lO~50μ).

(C) Output: 35KW (D) Distance: -100mo+ (E) Number of thermal sprays: 10 passes Also, Comparative Example 1 is one in which the surface of the cast iron base material is honed, and Comparative Example 2 is Chrome plating is applied to the surface of the cast iron base material.

The wear test was carried out using a rotating drive shaft IO in the form of a disc (diameter 200 aua, thickness 15 mm), as shown in FIG.
), and a pin 13 (
A chilled alloy cast iron) is attached to the other end of the arm 12 via a pulley 14.
ks 2W L shi -y 1 1
This is done by pressing L. Note that the test conditions are: circumferential speed of test piece 11 = 5
m/sec, weight of weight 15: 4.5 kg, test time: 10 minutes, under no lubrication and under lubrication [9 parts of kerosene and 1 part of engine oil (viscosity: 10W-40) were mixed. A certain amount of oil (l cc) at the beginning of the test
After dropping, the test was carried out.

The results of the above wear test are shown in Table 2.

Table 2 According to Table 2 above, inventive example 1.2 is comparative example 1.2.
It can be seen that it exhibits extremely superior wear resistance, lubricity, and seizure resistance compared to . Although Comparative Example 1 shows the same lubricity as the inventive example, it is significantly inferior in wear resistance.

Due to the mechanical properties described above, the sliding contact member of the present invention is most suitable for use as a rotor housing of a rotary engine or a cylinder liner of a reciprocating engine.

(Effects of the Invention) As described above, according to the present invention, graphite having self-lubricating properties (originally dispersed and contained in the sliding contact member) and hard wear-resistant material are dispersed and mixed on the surface of the sliding contact member. This has the excellent effect of improving wear resistance and seizure resistance, making it ideal for sliding contact members (for example, rotor housings, cylinder liners, etc.) of high-output, high-speed engines.

Furthermore, since the hard wear-resistant material is filled in the recesses formed on the surface of the sliding contact member by photoetching, it has good adhesion and is sufficiently durable for long-term use.

[Brief explanation of the drawing]

Fig. 1 is an enlarged organizational diagram of a sliding contact member according to an embodiment of the present invention, (a) is a surface view, (b) is a sectional view, and Fig. 2 shows the manufacturing process order of the sliding contact member of the present invention. FIG. 3 is a process diagram showing the order of the photoetching process, and FIG. 4 is a diagram showing an experimental apparatus for a wear test. 17... Base material 2... Graphite 3... Concavity 4... Hard wear-resistant material application person Mazda Corporation (A) CB) Figure 2 Figure 3 Figure 4 (D) (E) (B4 ) (8→

Claims (1)

[Claims] 1. A sliding surface with excellent wear resistance characterized by having a sliding surface in which graphite in the cast iron is dispersed and mixed with a hard wear-resistant material filled in a large number of recesses formed dispersedly on the surface of cast iron in which graphite is dispersed. Contact member.