JPS61266544A - Alloy for surface layers used as surface layers of sliding parts, plane bearing or the like - Google Patents

Abstract

PURPOSE:To improve the wear and corrosion resistances by adding prescribed percentages of Cu, In and Sn to Pb. CONSTITUTION:This alloy for surface layers used as the surface layers of sliding parts, a plane bearing, etc., consists of 0.1-6wt% Cu, 1-10wt% In and the balance Pb or further contains <=8wt% Sn. The alloy has superior wear, fatigue and corrosion resistances and a prolonged life.

Description

Detailed Description of the Invention (a) Industrial Application Field This invention is applicable to sliding parts and flat parts of automobiles, ships, food processing machines, OA equipment, agricultural machinery, machine tools, food machinery, and other general industrial machinery. It relates to a surface layer alloy (overlay alloy) used as a surface layer of bearings, etc.

(Extension) Conventional technology Conventionally, as this type of surface layer alloy, the following literature is available: "Sliding Bearing Materials" by Kazuyuki Morita, Engineer, 1967.9
"Recent Trends in Sliding Bearing Materials," Kazuyuki Morita, Engineer, April 1970, p. 90; As shown in Japanese Patent Publication No. 52-42128 and US Pat. , Pb-an alloy, 'Pb
-In alloy, 'pb-Eln -Ou gold alloy and Pb -
An-In alloy is used.

(c) Problems to be solved by the invention In recent years, internal combustion engines for automobiles and other general industrial machinery have been making rapid progress, and there is a trend toward higher speeds and heavier loads, and the sliding With the conventional surface layer alloys for bearings and sliding materials, the life of the bearings has been shortened due to lack of abrasion resistance, fatigue resistance, corrosion resistance, etc. due to a decrease in the lubricating oil film, especially under high speed and high load conditions. There was a problem.

2) Means for Solving the Problems The object of the present invention is to provide a surface layer that can withstand wear, fatigue, and corrosion caused by lubricating oil even when used as a surface layer of plain bearings and sliding materials under the above-mentioned high-speed and high-load conditions. The objective is to obtain an alloy for surface layer that can be used as a surface layer.

The alloy for the surface layer of the present invention has a weight of OuQ, 1 to 6To.

It consists of 1 to 10% In and the remainder Pt+ and unavoidable impurities. Another surface layer alloy of the present invention is CuO01 by weight.
~6%, In1~10tlI%, 8n13% or less, and the remainder consists of PB and inevitable impurities.

(E) Function Next, the reasons for limiting the composition of each component of the alloy for the surface layer of the present invention as described above will be described below.

(A) Ou: 0.1% to 6Ls by weight. C
If the amount of U is less than 0.1 inch, the load bearing capacity will be poor, and if the amount of Cu is 0.1 inch or more, there will be an effect of making the structure finer. Qu is 6
If it exceeds qlI, it becomes brittle. A more preferable range of ingredients is C! u1.596~5chi. This effect of Cu has the effect of making the surface layer alloy finer, which improves the load resistance and further has the effect of slowing down the diffusion of In into the base alloy. This effect extends the corrosion resistance life and, in turn, improves the fatigue resistance.

(B) In: 1% to 10% by weight. In amount is 1%
If it is less than 10 inches, the corrosion resistance will decrease, and if it exceeds 10 inches, the load bearing capacity will decrease. A more preferable range of ingredients is In2-9. In improves the corrosion resistance and wear resistance of the surface layer alloy.

(0) 8n: 8% or less by weight (not including zero), preferably from 0.51 to 81. When the amount of In is 3 or less, the above-mentioned alloy contains 1% or more of n, and the interaction between Sn and In greatly improves corrosion resistance, and it can withstand even severely corrosive oil. However, if Sn is 8 or more and the base alloy is a copper alloy, it will diffuse into the copper alloy and become thick and brittle. In
Create a reaction layer (compound layer). It has been confirmed through experiments that if the thickness of this reaction layer exceeds 6 microns, it becomes brittle and causes damage (top/L-), but if it is less than 6 microns, there is no problem. Further, even if the N1 barrier is used to prevent diffusion and the formation of a reaction layer, the fatigue life cannot be extended because the melting point is lowered. A more preferable range of ingredients is 8n1 to 7n.

(D) Combination effect of Pb-Ou-In and Pb-0u-In-8n: When In is added to a structure in which crystal grains are refined by Pb and CU, mechanical strength is improved by their interaction.

This alloy is the mechanically strongest surface layer alloy and also has excellent corrosion resistance. Furthermore, when several inches of 8n are added to this alloy, the interaction between 8n and In creates the effect of withstanding even extremely corrosive oil (such as degraded oil). Although the N1 barrier is generally not needed, if the N1 barrier is provided between the surface layer and the main body, it will have a long life and resist corrosion and fatigue even under severe usage conditions.

(Unavoidable impurities include impurities that cannot be avoided during manufacturing, such as 8b, Ni, ?θ, etc., and their individual or total amount is less than 0.5%.

(f) Example Examples of the present invention will be described below.

Pb and Ou are plated directly on the copper-lead alloy with steel backing or on top of the N1 plating using the Pb-Ou alloy plating solution composition and plating conditions shown in the first table, and then the In mark or I plating is applied.
n and 8n plating (conventionally known and publicly used plating solutions, e.g.
Bearing Lubrication Handbook, Nikkan Kogyo Shimbun, June 60, 1986, pages 367 to 668, pages 462 to 468. A semi-cylindrical plain bearing consisting of 6 or 4 layers was manufactured.

Plating conditions In the plating process in this example, the plating solution is an extremely stable alloy plating solution of PB and CU, so it is different from conventional PI)-s.
Continuous use was possible compared to n plating and 'Pb-Bn-Ou plating. Continuous plating was also possible while performing activated carbon filtration. Furthermore, in the plating treatment of this example, a dense plating (surface layer) with specular luster was obtained. For example, A
Rough surface 6~5μ without etching like 7 alloy
Even in the above case, leveling is good, and after plating is completed, the leveling is 0.1~
A surface of about 0.8μ was obtained.

Table 1 shows the composition, mechanical properties, corrosion loss, and thickness of the reaction layer with the base alloy of various bearing surface layer alloys according to the present invention in comparison with bearing surface layer alloys according to the prior art. Ta. As is clear from Table 1, the surface layer alloy of the present invention has higher hardness and tensile strength than the conventional surface 1 alloy, and can withstand high loads. When Ou reaches 5%, elongation decreases. Therefore C! u (more than 5% becomes brittle. Looking at the corrosion loss with degraded oil, Pb-an-In without N1 barrier
Except for alloys, conventional alloys have an or In diffused into the base,
Therefore, the corrosivity of the sample after heat treatment at 165° C. for 1000 hours due to deteriorated oil is remarkable. On the other hand, the surface layer alloy of the present invention has extremely high side-corrosion properties with a ratio of about 4 to 6 times that of conventional alloys. Especially P
b-Cu-In-day n is extremely good. The thickness of the reaction layer between the copper of the base alloy and the In and sn of the alloy of the present invention is thin and good, but if the amount of an is excessive, the reaction layer becomes thick. .

If the thickness of this reaction layer exceeds 3 microns, it has the disadvantage of becoming gradually brittle and prone to fatigue. The reason for the increase in corrosion resistance is thought to be that the addition of Cu reduces the diffusion of In into the base alloy, as is clear from FIG. When the N1 barrier is provided between the surface layer alloy and the base alloy, corrosion loss is extremely small and corrosion resistance is good. N
1. It is clear from FIG. 1 and Table 1 that even in the absence of a barrier, by containing a predetermined amount of Cu, the residual rate of In in the surface layer increases and corrosion resistance that can be practically used can be obtained. .

Next, we conducted a seizure test using a precious wood testing machine and investigated the amount of wear. The test conditions were as follows, and the shape and sample condition of the test piece (1) were as shown in FIGS. 2 to 4.

Shaft (2) material: 545Q # Lubricating oil: SA1! i3Q, 0.02-application shaft rotation speed when assembled: 78Q R, P6M.

Test piece: outer diameter 27.2ii to inner diameter 22IllIφ, depth 1 ring # (3), base material with steel backing (3
u 75%-P'b 25 copper alloy, the total thickness of the steel backing and copper alloy layer is 1.5 mm, and the thickness is 10 mm by electroplating.
Alloy for μm surface layer? Established.

Test time’70 min.

Table 2 shows the average values of the seizure load and wear thickness under the condition of lubrication with one drop (0.02 d) of oil applied only during assembly. The surface layer alloy of the present invention has a high seizure load and a small wear thickness.

Next, the fatigue resistance of the surface layer alloy of the present invention was investigated by a bearing fatigue test using a sapphire tester. The test conditions are as follows.

Shaft material: 5ssa, shaft diameter: 53mm φ Test bearing: Sintered copper-lead alloy with steel backing (CU 75%-41) 25%) was plated with various surface layer alloys shown in Table 6 to a thickness of 15 μm. Connecting rod bearing, test bearing outer diameter = 56', test bearing wall thickness = 1.5 cm, test bearing width = 26.0 vx0 # Lubricating oil type and temperature: sAg20. 90°C rotation speed:
3250 r, p, m・Test time = 20 hours, Test load: 1330 kg/am” As is clear from Table 6, the alloy of the present invention did not cause fatigue cracks, and the Pb-5 The reason why a small area was observed in the chain n-1 chain was due to part of the destruction of the base alloy.

Next, the surface layer alloy of the present invention was subjected to a repeated test of 6 times. The test conditions are as follows.

Test machine used: Motorcycle engine 35 horsepower Shaft rotation speed: 1
3000r, p, m Shaft diameter: 33sot Shaft material: 5soc Test time: 10 hours Lubricating oil: 8Affi2Q$ Lubricating oil temperature = 145-150°C Test load = full load Test bearing: Outer diameter 36.0m, wall thickness 1 .5sow, width 1
3.8m, after plating the N1 barrier on the bearing (Steel-lead sintered alloy with steel backing (Cu-75-Pb 25-chi)) using the alloy for the surface layer shown in Table 4, a 15 μm thick layer was formed by plating. The thickness was set.

As shown in Table 4, the surface layer alloy of the present invention showed no cracks and was found to be extremely resistant to fatigue.

(g) Effects of the Invention As shown in the Examples, the invented alloy is superior to any of the conventional surface layers and was able to satisfy and achieve the intended purpose of the invention. The appearance of the surface layer alloy was also extremely good.

[Brief explanation of drawings]

Figure 1 is a graph showing the relationship between the amount of O in the surface layer alloy and the In residual rate in the surface layer alloy after heat treatment, and Figure 2 is a graph showing the front view of the test piece used in the seizure test. FIG. 3 is a sectional view taken along line i-1 in FIG. 2, and FIG. 4 is a sectional view showing the state of the seizure test. 1 shows a test piece for the seizure test.

Claims (2)

[Claims] (1) An alloy for a surface layer, which is used as a surface layer of sliding parts, plain bearings, etc., and consists of 0.1 to 6% Cu, 1 to 10% In, and the balance Pb and inevitable impurities. (2) Used as a surface layer for sliding parts and plain bearings, Cu 0.1-6%, In 1-10%, Sn 8% by weight
An alloy for surface layer consisting of Pb and unavoidable impurities.