JPS62253779A - Production of sliding member having excellent wear resistance - Google Patents

Abstract

PURPOSE:To produce a sliding member having excellent wear resistance by melting hardness imparting powder into the surface of a metallic base material by a high-density energy heat ray and adequately adjusting an assist gas to disperse and form may oil holding recesses. CONSTITUTION:A laser beam L condensed to a spot shape by a lens 6 is irradiated from a nozzle 7 of a laser irradiating device 4 to the hardness imparting powder 2 preliminarily coated on the surface of the metallic base material 1 to melt the powder 2 into the material 1 by which a hard layer 3 is formed. The gaseous pressure of the assist gas G such as Ar or N2 which is introduced from a supply pipe 8 and is ejected from the nozzle 7 is regulated to 1.0-3.0kg/cm<2> in this stage. The central molten metal in the remelting part is thereby extruded in the stage of forming the above-mentioned hard layer 3 and the many oil holding recesses 9 enclosed by the hard layer 3 are dispersed and formed. The parts projecting from a sliding contact surface 10 are thereafter ground to obtain the sliding member.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention has a large number of oil retaining recesses on the surface. This invention relates to a method of manufacturing a sliding member with excellent wear resistance.

(Prior Art) Conventionally, a hard layer is formed by attaching a coating material such as Cr or Mo to the surface of a metal base material and melting the coating material into the surface of the base material using an electron beam or the like.

Methods for obtaining sliding members with excellent wear resistance are known (for example, Japanese Patent Application Laid-Open Nos. 55-148752 and 1988-1).
(See Publication No. 01254).

However, on the surface of the sliding member obtained by the above method,
In order to form a large number of oil retaining recesses that provide good lubricity and improve wear resistance, a new process for processing the hard layer must be added.

(Object of the Invention) The present invention has been made in view of the above-mentioned conventional problems, and has been developed by adjusting the assist gas pressure when melting the hardness imparting powder onto the surface of the gold B base material using high-energy hot rays. The purpose is to simultaneously mold a hard layer that improves abrasion resistance and an oil retention recess.

(Structure of the Invention) In order to achieve the above object, a method for manufacturing a sliding member with excellent wear resistance was developed by melting a hardening powder onto the surface of a metal base material using a high-density energy hot wire. While forming a layer, 1. It is characterized in that a large number of oil holding recesses surrounded by a hard layer are dispersed by applying an assist gas pressure of 0 to 3.0 kg/-.

(Example) 1 to 3 show a first embodiment of the present invention.

In this example, the hardness imparting powder 2 is applied on the surface of the metal base material l in advance, and a spot-shaped laser beam L is irradiated to melt the hardness imparting powder 2 into the metal base material l. A hard layer 3 is obtained. Examples of the metal base material 1 and the hardness imparting powder 2 include combinations as shown in Table 1 below.

The laser beam irradiation device a4 in Table 1 has a lens 6 in the body 5.
The laser beam L focused by is irradiated from the nozzle 7. The assist gas G is blown out in front of the lens 6 through the assist gas supply pipe 8 and is discharged from the nozzle 7. The assist gas G is used for two purposes: to prevent spatter from scattering from the workpiece and adhering to the lens 6, and to control the laser processing atmosphere. Incidentally, in the heat treatment as in the present invention, an inert gas such as Ar or N is used. As will be detailed later, when the assist gas pressure is adjusted, in the process of forming the hard layer 3,
The molten metal in the center of the remelted part is extruded, and an oil holding portion L'1 9 of an appropriate size is formed (see FIG. 2).

If a finishing process is performed by grinding, the portion of the hard layer 3 that protrudes from the sliding surface 10 is removed (see FIG. 3).

FIG. 4 shows Example 2. In this embodiment, the powder supply device 11 is used to supply the hardening powder.

It is designed to irradiate a laser beam [5],
There is no difference from Example 1 in other configurations, and the effects are also the same. The same reference numerals are used for the same members as in the first embodiment.

Next, the wear resistance test conducted by the inventor will be explained in detail.

■Preparation of sample The gold a base material is AQ alloy AC8A with T6 treatment.
One composition using is shown in Table 2 below.

Table 2 The inventor adhered Si powder to the surface of the metal base material with an acrylic resin to a thickness of about 100 μm, and irradiated the Si powder with a laser beam under the conditions shown in Table 3 below to dissolve it into the metal base material. It was crowded.

Table 3 At that time, the assist gas pressure was set to various values, and the relationship between the gas pressure and the oil holding recess formed was investigated. The results are shown in Table 4 below and Figures 5 to 9.

Figure 5 shows sample 1. FIG. 6 shows the cross section of the oil retaining recess 9 of Sample 2, FIG. 7 shows Sample 3, FIG. 8 shows Sample 4, and FIG. 9 shows Sample 5.

Table 4 As shown above, assist gas pressure is 1. 0kg/af1
If it is less than 3.0 kg/-, holes will not form, while if it is stronger than 3.0 kg/-, most of the hard layer will be scattered. Therefore, in order to make a hole with a diameter of 100 to 200 μrn and to form a hard layer around the hole, the assist gas pressure should be 1.0 to 3.
．． It has to be 0kg/ad.

By the way, in sample 1, ? ? The thickness of J layer 3 is approximately 5
00 μm. Further, in sample 41, the depth of the oil holding recess 9 is approximately 300 μm. Moreover, in any sample, the hardness of the gold B base material is F1v135 (Vickers hardness), and the hardness of the hard layer is 11v250.

■Test method The inventor has developed a disk 12 (φ=2
00M, t=loo+m) and a bottle 13 made of alloyed cast iron as shown in FIG. 11 (Q,=1011n).

Q, = 4 mm, Q, -= 8 mm
, the composition of which is shown in Table 5 below) was prepared, a Zeon disc type wear tester 14 as shown in FIG. 12 was constructed, and tests were conducted under the conditions shown in Table 6 below.

Table 5 Table 6 The test results are shown in Table 7 below. 1. Sample 2 was used as the disk material of the present invention.

In addition, as the disk material for Comparative Example, AC8A which had been subjected to only 6 treatments was used, and as the disk material for Comparative Example 2, Sample 1 was used.

Comparative Example 2 in Table 7 has a harder disk than Comparative Example 1, so the amount of jf wear on the disk is less, but on the other hand, the bottle is worn more. On the other hand, in the example of the present invention, the disk is also hardened and the oil retention property is improved, so the amount of wear of both the disk and the bottle is smaller than that of Comparative Example 1.2.

As shown in FIG. 13, as an application example of the sliding member obtained by the present invention, a rocker arm 15 of ΔQ'ilJ can be raised. The boss hole of the rocker arm 15 and the sliding part of the rocker shaft 16, especially the part S in the figure, retain oil better during operation.

Problems such as scuffing and wear occur in the boss hole, but if the sliding member obtained according to the present invention is applied to the sliding portion, such problems can be eliminated, which is advantageous.

(Effects of the Invention) According to the present invention, an excellent effect can be obtained in that the hard layer that improves wear resistance and the oil retaining recess can be simultaneously molded by adjusting the assist gas pressure.

[Brief explanation of drawings]

Figures 1 to 3 are sectional views showing a series of steps in one embodiment of the present invention, Figure 4 is a sectional view for explaining another embodiment, and Figure 5 is a sample 1 prepared by the inventor. 6 is a sectional view of the same sample 2, FIG. 7 is a sectional view of the same sample 3, FIG. 8 is a sectional view of the same sample 4, FIG. 9 is a sectional view of the same sample 5,
FIG. 0 is a perspective view of a disk used in the wear test, FIG. 11 is a perspective view of a bottle, FIG. 12 is a front view of the entire test apparatus, and FIG. 13 is a front view of a rocker arm. 1...Metal base material, 2...Hardness imparting powder, 3...
...Hard layer, 4...Laser beam irradiation device, L...Laser beam. 81 Figure 84 rw Figure 2 Gen5 Figure Seat Figure 10

Claims (1)

[Claims] (1) Form a hard layer by melting the hardening powder on the surface of the metal base material with high-density energy heat rays, and
．． A method for manufacturing a sliding member with excellent wear resistance, characterized in that a large number of oil holding recesses surrounded by a hard layer are dispersed by applying an assist gas pressure of 0 to 3.0 kg/cm^2.