JPS62133043A - Fe sintered material impregnated with cu - Google Patents

Abstract

PURPOSE:To develop a sintered sliding material having excellent wear resistance and fit to a mating material by impregnating Cu or Cu-Sn alloy to a porous sintered body consisting of the powder of a high-carbon alloy steel contg. Cr and Mn. CONSTITUTION:Powder of Fe-Cr, Fe-Mn or Fe of <=100 mesh and graphite powder of <=350 mesh are mixed to contain 1-4% C, 3-20% Cr, 0.05-3.5% Mn, and the balance Fe and further 0.7% zinc stearate is added as a lubricant. The powder mixture composed thereof is subjected to press molding and the molding is sintered at 1,100-1,180 deg.C to form the sintered body finely dispersed with hard metallic carbide. Cu powder of <=100 mesh or Cu-Sn alloy powder contg. 0.1-25% Sn is superposed thereto and in this state the sintered body is heated to 1,130 deg.C by which the sliding member melted and impregnated with Cu or Cu-Sn alloy in the pores of the sintered body so as to be incorporated therein at 6-25wt%.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention has excellent wear resistance and excellent compatibility with mating members, and is particularly applicable to sliding members that require these characteristics and wear-resistant Cu-impregnated F suitable for use in manufacturing parts
This relates to e-based sintered materials.

[Prior Art] In general, P, Fe-based sintered material densified by liquid phase sintering by adding B532 is used.

[Problem that the invention seeks to solve]

However, in the conventional liquid phase sintered Fe-based sintered materials mentioned above, those with good wear resistance have poor compatibility with mating parts, while those with good compatibility have poor wear resistance. At present, the characteristics are not fully met.

[Means for solving problems]

Therefore, the present inventors conducted research from the above-mentioned viewpoint, and as a result, the following results were obtained: heavy@duck (hereinafter % indicates weight %): C: 1 to 4%, Cr: 3 to 20%.

Cut is applied to a porous Fe-based sintered alloy body containing Mn: 0.05 to 3.5%, with the remainder consisting of Fe and unavoidable carbon dioxide, and a structure in which carbides are finely dispersed in the matrix. or 8n: 0.1-2
The proportion of Cu-Sn alloy containing 5% to the total is 6 to 5%.
The Cu-impregnated Fe-based sintered material impregnated with 25% has excellent wear resistance and compatibility with mating parts, and is excellent when used as various sliding parts and wear-resistant parts. We have gained knowledge that it can perform well.

This invention was made based on the above knowledge, and the reason why the component composition and the amount of impregnation were limited as described above will be explained below.

(a) C The C component not only dissolves in the matrix to strengthen it, but also forms carbides that are finely dispersed in the matrix and precipitates cementite during heat treatment to improve hardness. It has the effect of improving wear resistance, but if its content is less than 1%, the desired excellent wear resistance cannot be guaranteed, while if its content exceeds 4%, carbide As the amount of cementite becomes too large and segregation occurs in its distribution, not only the conformability decreases but also the aggressiveness towards the mating member increases, which further causes a decrease in strength. Since the formation of free carbon also occurs, its content was determined to be 1-4%.

(b) Cr The Cr component includes solid solution in the base material to strengthen it.
It combines with the C component to form fine (bidispersed) hard carbides in the base material, which has the effect of improving wear resistance, but if its content is less than 3%, the desired wear resistance cannot be achieved. On the other hand, if the content exceeds 20%,
The content was set at 3 to 20% because it lowers familiarity and increases aggressiveness to opponents.

(c) Mn The Mn component has the effect of improving conformability by being dissolved in the base material, but if its content is less than 0.05%, the desired conformability cannot be secured; Content is 3
．． If it exceeds 5%, the press formability of the powder will deteriorate and the sinterability will also decrease, making it difficult to secure the desired strength.
．． It was set at 5%.

(dl Impregnating amount Cu or Cu-Sn alloy as an impregnating material has the effect of densifying the material and increasing the material strength as well as improving the compatibility with the mating member, but the porosity of the sintered alloy body In relation to this, if the amount of impregnation is less than 6% of the total material, it will not be possible to secure the desired excellent compatibility and low aggressiveness. If the proportion exceeds 25%, the wear resistance of the material will drop significantly, so the amount of impregnation was set at 6 to 25%.

Moreover, as an impregnating material, in addition to Cu as mentioned above, C
+r-Sn alloy is used, but the use of this Cu-Sn alloy enables infiltration at low temperatures, and therefore the Sn content in the Cu-Sn alloy is 0.
If the Sn content is less than 1%, it will not be possible to achieve the desired reduction in the melting temperature.On the other hand, if the Sn content exceeds 25%, there will not be a significant decrease in the melting temperature. For this reason, the Sn content in the Cu-Sn alloy was set at 0.1 to 25%.

Note that the Fe-based sintered alloy main body to be impregnated and the impregnating material may be molded separately, or may be molded integrally during compaction.

〔Example〕

Next, the Cu-impregnated Fe-based sintered material of the present invention will be specifically explained with reference to Examples.

The raw material powders were Fe-Cr alloy (containing 23% Cr) powder, Fe powder, and Fe-excited alloy (containing 80% Mn) powder, each having a particle size of 100 and z, and graphite powder with the same 350-mesh size. were prepared, these raw material powders were blended into the blending composition shown in Table 1, and after adding 0.7% zinc stearate as a lubricant to the blended powder, they were mixed, and 4 to 7 ton / −
The compacted powder for the rocker arm chip is formed by press molding at a pressure within the range of
Under the conditions of holding at a temperature of 1000°C for 60 minutes in a vacuum of 3 torr, and for a sintered body, the same < I × 10
Sintering is carried out in a vacuum of -3 torr and maintained at a temperature within the range of 1100 to 1180°C for 90 minutes, and then the green compact, which will become the porous Fe-based sintered alloy body prepared in this way, is Sintered body, sintered body, and separately prepared grains II-1
00 mesh Cu powder and Cu-Sn alloy (Sn:
25% containing) powder, blended with the composition shown in Table 1, mixed, and press-molded at a pressure of 3 ton/ad to prepare a green compact for impregnation. I X 1O-2tor
Rocker arm chips each made of the Cu-impregnated Fe-based sintered materials 1 to 7 of the present invention were manufactured by performing an impregnation treatment in a vacuum at 1,130° C. for 30 minutes.

Next, these rocker arm chips were cast by 1M die-casting to manufacture a rocker arm, and this was assembled into a gasoline engine.Engine: 1400cc,
4-cylinder, OHC gasoline engine, rotation speed: 750 r, p, m, operating time: 200 hours, lubricating oil: degraded oil, camshaft material: FC25 chill casting. The maximum wear depth of the rocker arm tip and the maximum wear depth of the cam, which is a mating member, were measured. These measurement results are shown in Table @1. Table 1 also shows the amount of infiltration.

〔Effect of the invention〕

In the whip, under similar operating conditions, the maximum wear depth = 10 to 30 μm, and the maximum wear depth of the mating member cam:
In comparison, the present Cu
It is clear that impregnated Fe-based sintered materials 1 to 7 all exhibit excellent abrasion resistance, good conformability, and extremely low attackability.

As mentioned above, the Cu-impregnated Fe-based sintered material of the present invention is
Since it has excellent wear resistance and conformability, it exhibits excellent performance over a long period of time when used as various sliding members or wear-resistant members.

Claims (1)

[Claims] A composition containing C: 1 to 4%, Cr: 3 to 20%, Mn: 0.05 to 3.5%, with the remainder consisting of Fe and unavoidable impurities (wt%), In addition, Cu or S
A Cu-impregnated Fe-based sintered material having excellent wear resistance and conformability, which is obtained by impregnating a Cu-Sn alloy containing n: 0.1 to 25% by weight in an amount of 6 to 25% by weight relative to the whole.