JPS6035978B2 - Wear-resistant copper-tin based sintered oil-impregnated bearing material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copper-tin-based baked oil bearing material, in which nickel or cobalt is added to the composition of an existing material, and lead, graphite, molybdenum disulfide, etc. are added as a solid lubricant. The present invention provides a bearing village in which the wear resistance is significantly improved by the synergistic effect of the two.

Sintered oil bearings generally consist of a base alloy phase that is difficult to seize against the mating material, the shaft, and the creation of oil-impregnated holes that supply lubricating oil to the sliding surfaces, and if necessary, solid lubricants are added to this. Lubrication during sliding is maintained by both.

The inventors of the present invention observed the sliding surfaces of copper-tin competitive oil-impregnated bearings to which solid lubricants such as poly-6, graphite, and molybdenum disulfide were added. It was found that a considerable portion of the solid lubricant was covered with a thin layer of the base alloy and did not appear on the sliding surface.

This is due to plastic deformation of the base alloy, and means that the solid lubricant that has been added to the base alloy cannot work effectively. The present invention aims to strengthen the base alloy by adding nickel or cobalt to prevent its plastic deformation, thereby fully exhibiting the function of a solid lubricant. The gist of the method is to add 1 to 2 tsubo of at least one of nickel and cobalt to the solidification material containing the agent.

Hereinafter, the present invention will be described in detail with reference to embodiments thereof.

First, electrolytic steel powder with a particle size of 100 mesh or less, tin powder with a particle size of 100 mesh or less, nickel powder with a particle size of 200 mesh or less, molybdenum disulfide powder, and lead powder were prepared and mixed in the proportions shown in Table 1 for each sample. Five types of samples with a non-condensation density of 6.9 mm were prepared by molding and feeding in the usual manner, namely, samples and reference samples to examine the effects of nickel in cases where the solid lubricants were molybdenum disulfide and lead, respectively. A copper-tin alloy was prepared, impregnated with No. 2 turbine oil, and subjected to the sliding test described below.

In addition, the symbol "Book 1" in the table refers to "Inventive material 1" and "Ratio 1".
is an abbreviation for "Comparative material 1", and the other three types are also similar to this.

・Next, for the present invention material 1 and comparative material 1 in the above samples, carburized and hardened chrome steel SCr420 was used as the counterpart material of the alcohol, and surface pressure of 5 kg/, Surien 240 skin/skin was 5. A feeding time sliding test was conducted to compare the changes in the sliding surface before and after the test.

Figures 1 to 6 are micrographs showing the results,
1 and 3 are photographs showing the metal structure of the sliding surface of Comparative Material 1 before and after the sliding test, respectively, and FIG. 5 is a photograph showing the metal structure of the sliding surface of Inventive Material 1 after the sliding test, and Figures 2, 4, and 6 are shown in the same field of view as Figures 1, 3, and 5 above, respectively, to clarify the state of molybdenum disulfide on the sliding surface. This is a photograph showing the results of a field analysis using characteristics of the element sulfur x rays, and the white part in the field of view indicates the presence of molybdenum disulfide with no sulfur content.

From these photographs, we can see that in the comparison material that does not contain nickel, very little molybdenum disulfide is exposed on the sliding surface after the sliding test, whereas in the case of the inventive material that contains 3% nickel. Even after the test, most of the E-libdenum disulfide was found exposed on the sliding surface, and it is presumed that it acts effectively as a lubricant.

Next, a drinking test was conducted on the five types of samples under the following conditions, and the amount of wear of each sample was compared.

Mating material: Bearing steel SUJ2 heat treated material Surface pressure: 8k
9/Sake consumption...2/Figure 7 shows the results. In the figure, the curve with black circles represents the sample of the conventional material, and the curve with white circles represents the sample of the material of the present invention. There is.

This graph confirms the conventional knowledge that the addition of solid lubricants to copper-tin alloys is effective in improving wear resistance, and that the latter is more effective for lead and molybdenum disulfide. This shows that the combined use of a solid lubricant and nickel further significantly improves wear resistance.
This is considered to be due to the fact that the addition of nickel strengthens the matrix and makes it difficult to plastically flow, together with the results of the above-mentioned surface analysis. Next, FIG. 8 shows the results of investigating the relationship between the amounts of molybdenum disulfide and nickel added and the amount of wear.

The sliding test was carried out using a carburized and hardened SCr420 material as the mating material, and the sliding test was continued for 10 q hours at a surface pressure of 5 kg/side and a sliding speed of 600 skin/side. It shows the area where this occurred. From this result, the amounts of molybdenum disulfide and nickel added are preferably in the range of 5 to 10% for the former and 6 to 13% for the latter.

The minimum amount required to prevent burn-in is 2% and 1, respectively.
%It can be seen that it is. Furthermore, if the former exceeds 15%, the material will become noticeably shaped into arms, resulting in increased wear, while if the latter exceeds 20%, the base will become excessively hardened and its compatibility with rattan will decrease. Therefore, this value was determined as the upper limit of each amount added. The usual tin addition rate in copper-tin sintered alloys is 8 to 11%, but nickel has the effect of toughening this base (cobalt has the same effect as nickel).

) is also expressed outside this compositional range.

[Brief explanation of the drawing]

Figures 1 to 6 are all microscopic photographs, with Figures 1 and 2 taken before the sliding test of comparative material 1, and Figures 3 and 4 taken after the sliding test of comparative material 1. , 5 and 6 are photographs showing the results of the metallographic structure and surface analysis, respectively, after the sliding test of Inventive Material 1. Figure 7 is a graph comparing the wear resistance of various samples, and Figure 8 is a graph comparing the wear resistance of various samples. The figure is a graph showing the relationship between the amounts of nickel and solid lubricant added and wear resistance. Reeds, straw, snow rhombuses, 5 6 Figure 7 Figure 8

Claims (1)

[Claims] 1 A wear-resistant copper-tin-based sintered product characterized by containing 1 to 20% by weight of at least one of nickel and cobalt, and 2 to 15% of at least one of molybdenum disulfide and lead as a solid lubricant. Oil-impregnated bearing material.