JPH0336226A - Copper-base sintered alloy having excellent wear resistance at high temperature - Google Patents

Abstract

PURPOSE:To manufacture a copper-base sintered alloy having excellent wear resistance at a high temp. by preparing a copper-base sintered alloy contg. specified ratios of Zn, Fe, Ni, Co and O and having the structure in which fine oxides and intermetallic compounds are uniformly dispersed into a matrix and a specified quantity of vacancies are distributed. CONSTITUTION:A copper-base sintered alloy having the compsn. contg., by weight, 5 to 25% Zn, 0.1 to 3% of one or more kinds among Fe, Ni and Co, 0.01 to 0.5% O and the balance Cu with inevitable impurities and having the structure in which fine oxides and intermetallic compounds are uniformly dispersed and 1 to 15vol.% vacancies are distributed is prepd. In this way, the copper-base sintered alloy having excellent wear resistance and seizure resistance at a high temp. and showing excellent capacity for a long period of time can be obtd., which is suitable to a bearing, e.g. for a guide bush of an internal combustion engine.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a copper-based sintered alloy that has excellent wear resistance under any conditions from room temperature to high temperature, and in particular has excellent wear resistance under high temperature conditions. The present invention relates to a copper-based sintered alloy that has excellent properties, and is suitable for use as guide bushings for internal combustion engines, bearings for turbochargers, and the like.

[Conventional technology]

Conventionally, in the manufacture of the various members mentioned above, Cu -28%Zn -6%A, Q is used in weight% (hereinafter % indicates weight%).
A copper-based alloy having a typical composition was used.

[Solution to be Solved by the Invention] [D] However, when the above-mentioned conventional copper-based alloys are used from relatively low to high temperatures, seizure occurs, especially at high temperatures, and there are problems with wear resistance. Ta.

As the output of modern internal combustion engines increases, the sliding parts of the engines are exposed to higher temperatures than before. Development was strongly desired.

[Means to solve the problem]

Therefore, from the above-mentioned viewpoint, the present inventors focused on the conventional copper-based melt-produced alloys, and aimed to develop a copper-based alloy that has even better seizure resistance and wear resistance at high temperatures. As a result of research, Zn+5 to 25%, one or more of Fe, Ni, and Co, 0.
1 to 3%, oxygen: 0091 to 0.5%, and if necessary, (a) A, full: 0. ] ~0.3%, (b)
Mn: 0.1 to 3%, (c) one or more of Cr, Mo, and W: 0.1 to 2%, any one of the above (a) to (C) or A composition containing two or more types, with the remainder consisting of Cu and unavoidable impurities, and a structure in which fine oxides and intermetallic compounds are uniformly dispersed in the matrix, and pores have a volume ratio of 1 to 15%. The knowledge that copper-based sintered alloys with sintered alloys have improved wear resistance at room and high temperatures, and that the presence of fine oxides and pores in the matrix improves seizure resistance at high temperatures. I got it.

This invention was made based on this knowledge, and the copper-based sintered alloy of this invention has the above composition.
In the matrix, oxides distributed within the particle size range of 1 to 40 μm are uniformly dispersed at an area ratio of 0.1 to 7%, and
Intermetallic compounds distributed within the particle size range of 25 IMl
These oxides and intermetallic compounds exist in the matrix, with pores in the particle size range of 1 to 40 being uniformly distributed at an area ratio of 8% and a structure uniformly distributed at a volume ratio of 1 to 15%. By doing so, the wear resistance at room temperature and high temperature is significantly improved15, and the presence of these oxides and pores in the base material significantly improves the seizure resistance at high temperatures.

Next, the reason why the composition and pores of the copper-based sintered alloy of the present invention are limited as described above will be explained.

(a) Porosity The amount of pores distributed on the sliding surface has the effect of improving seizure resistance, especially at high temperatures, but this effect cannot be obtained when the amount is less than 1% by volume. If there is a large distribution, not only the strength will decrease, but also the heat resistance will deteriorate due to a decrease in thermal conductivity, and the seizure resistance at high temperatures will decrease.
It is also undesirable because it reduces wear resistance.

Therefore, the distribution amount of pores was determined to be 1 to 15% by volume.

(b) Zn Zn forms a matrix together with CI and has the effect of improving the strength and toughness of the alloy, and also combines with oxygen (to form an oxide), improving seizure resistance at high temperatures and resistance to corrosion at room and high temperatures. However, if it is less than 5%, it has no effect, while if it is more than 25%, the thermal conductivity decreases and the fire resistance (=I) at high temperatures decreases. begins to decline.

Therefore, the Zn content is set at 5 to 25%.

(C) Oxygen Oxygen contains Cu, Zn, and optionally AI! , W, Mo and Cr to form oxides that are uniformly and finely dispersed in the base material, 'l; (Improves wear resistance at warm and high temperatures, especially improves seizure resistance and heat resistance. It has the effect of improving wear resistance under high temperatures, but if it is less than 0.01%, it has no effect, while if it is contained more than 0.5%, the particle size of the oxide is 40%.
Not only does it become coarse, exceeding .mu.m, but it also becomes excessively large, exceeding 7% in terms of area ratio, which is undesirable because it not only reduces the strength and toughness of the alloy, but also increases its aggressiveness.

Therefore, the oxygen content was determined to be 0.01 to 5%.

0 (d) Fe, Nt and C.

All of these components are dispersed in the base material to improve the strength and toughness of the alloy, and are combined with Cu and A, &, W, Mo and Cr contained as necessary and dispersed in the base material. Forms fine intermetallic compounds,
It improves wear resistance, improves heat resistance, and has an effect on seizure resistance, but if its content is less than 0.1%, the desired effect cannot be obtained; on the other hand, if its content is 3% If the content exceeds the above range, it is not preferable because the toughness and thermal conductivity decrease, resulting in deterioration of seizure resistance.

Therefore, Fe, Ni It was set at 0.1 to 3%.

(8) A, 9 Ap not only forms a matrix with high strength and toughness together with Cu and Zn, but also combines with oxygen to form an oxide, which improves seizure resistance at high temperatures and at room and high temperatures. has the effect of improving wear resistance, but if its content is 0.
If the Co content is less than 1%, the desired effect will not be obtained, while if the content exceeds 0.3%, the thermal conductivity will decrease and the seizure resistance will deteriorate. So I don't like it.

Therefore, the Ag content was set at 0.1 to 0.3%.

0°) W, Mo and Cr These components all combine with FC, Ni and Co to form fine intermetallic compounds dispersed in the matrix,
It also combines with oxygen to form fine oxides, which have the effect of improving wear resistance and burn-in resistance, but if the content is less than 0.1%, the desired effect cannot be obtained. On the other hand, if the H content exceeds 2%, the toughness decreases, which is not preferable.

Therefore, the content of W, Mo and Cr is 0.1~
It was set at 2%.

(g) Mn Mn forms a solid solution in the base material and has the effect of improving strength. However, if its content is less than 0.1%, the desired effect cannot be obtained; on the other hand, if its content is less than 3%, If the content exceeds 2, the heat resistance will decrease, and the seizure resistance and abrasion resistance at high temperatures will decrease, which is not preferable.

Therefore, the Mn content was set at 0.1 to 3%.

The copper-based sintered alloy of the present invention may contain P, Mg, Sn, and Pb as unavoidable impurities, but if the total content is 1.5% or less, the alloy properties will not be impaired in any way. Since it is not a substance that can be used as a substance, its content can be tolerated.

〔Example〕

Next, the copper-based sintered alloy of the present invention will be specifically explained with reference to Examples.

As raw material powder, Cu
-5% Zn alloy powder, CIJ-30% Zn alloy powder, C
u powder, Zn powder, A, Q powder, Mn powder, Mo powder,
W powder, Cr powder, Fe powder, N1 powder, and Co powder were prepared, and these raw material powders were blended into the composition shown in Table 1, and after pulverizing and mixing with a V-type mixer for 3 hours, 5 to 7 tons of powder was prepared. Press the bottom of the compact into a compact at a predetermined pressure within the range of /cd, and keep it at a predetermined temperature within the range of 850 to 950 °C for 1 hour in hydrogen gas with a dew point of 0 °C to -30 °C. After sintering under the specified conditions, and then holding it at a predetermined temperature within the range of 400 to 600°C for 1 minute as necessary to control the amount of pores, repressurizing it allows it to be used for crushing load measurement. Outer diameter: 60mvas Inner diameter: 50
Cu-based sintered alloys 1 to 34 of the present invention and comparative Cu2!, which are composed of rings having dimensions of m+n, thickness: IOmn, and have the compositions shown in Table 1. Sintered alloys 1 to 10 were used for wear measurement as round bars with dimensions of diameter: 10 mm and height: 30 mm, and outer diameter: 12 mrn, inner diameter +6 mm.
, Length: Cu-based sintered alloys 1 to 34 of the present invention and comparative Cu-based sintered alloy 1 consisting of pipes having dimensions of 45 mm.
~10 were prepared, respectively.

Further, conventional Cu-based melt alloys were manufactured by melting and casting using a conventional melting method and having the compositions shown in Table 1, consisting of rings, round bars, and pipes having the above-mentioned dimensions.

Note that Cu-based sintered alloys 1 to 34 of the present invention all had a structure in which fine oxides and intermetallic compounds were uniformly dispersed in the base material.

In addition, the comparative Cu-based sintered alloys 1 to 0 each have a content of one of the constituent components or a vacancy content (marked with * in Table 1 by i and j) of the present invention. It's out of scope.

Next, for the purpose of evaluating the strength and toughness of various Cu-based sintered and ingot alloys obtained as a result, we measured the crushing load at room temperature of the ring divided into three samples, and further measured the crushing load at high temperature. For the purpose of evaluating wear resistance, the following wear test was conducted.

Wear test ■ Various C of above diameter = 10 sum m1 height + 30n + vA
U-based sintered alloy and ingot alloy round bar are processed to have a diameter of 1
．． A 5 mm pin was prepared, and a chromium-plated SUH disk was prepared as a mating material. 11. While heating the disk to 580° C. with a burner from the back side of the disk, the circumferential speed was set to 2. Rotate at 0m/see, while pressing the above pin (= 1 load, 51<g) against the above disc, and while dropping 5 W -30 oil, slide the total 5 sliding distance + 18 km, and press it against the mating material. In order to evaluate synchronization characteristics at high temperatures, a pin-on-disk friction and wear test was conducted, and the presence or absence of seizure was investigated using a torque meter based on changes in the generated torque.
Shown in the table.

Wear test ■Cu-based sintered alloy and Cu-based alloy pipes having the above dimensions of outer diameter: 12 mm, inner diameter +6 mm, length: 45 mm were processed to have outer diameter: 11 mm, inner diameter: 6.5+++
+n.

Various Cu-based sintered and melted alloy samples with dimensions of length: 45 mm were manufactured, while S U H4J was used as the counterpart material.
Salt bath nitrided diameter + 6.85mm, length 150
A mm round bar was prepared.

The above-mentioned round bar as the mating material is screwed into the pipe hole of the sample, and while heating one end of the round bar as the mating material with a burner, the atmospheric temperature at one end is set to 520°C, and the sample is pressed against the mating material under a load.
While pressing with 5 kg and dripping 5W-30 oil, slide the round bar which is the mating material in the axial direction of the pipe hole at a sliding distance of +15 mm at 3500 strokes/min.
A wear test was conducted under the condition of 0 minutes of sliding, and the amount of wear was measured.The presence or absence of seizure and the surface condition of the mating material were also observed.The results are shown in Table 1.

Regarding the surface condition of the mating material, those with no scratches are marked O, those with some scratches due to burn-in are marked with Δ, and those with wear scratches on the surface are marked with X. They were distinguished by

〔Effect of the invention〕

From the results shown in Table 1, Cu-based sintered alloys 1 to 1 of the present invention
All of No. 34 have superior wear resistance and seizure resistance at high temperatures compared to conventional Cu-based melt-produced alloys, and as seen in Comparative Cu-based hardened alloys 1 to 10, If any of the constituent composition and pores falls outside the scope of the present invention, at least one of wear resistance, seizure resistance, and aggressiveness at high temperatures, and strength and toughness at room temperature will deteriorate. It is clear that the quality is inferior.

As mentioned above, the CIJ-based sintered alloy of the present invention has excellent wear resistance and synchronization properties at high temperatures, so it can be used as a structural benefit for various types of equipment that are exposed to high temperatures associated with higher output. In practical use, it exhibits excellent performance over a long period of time, resulting in excellent industrial efficiency.

Out wish Man Mitsubishi Metals Corporation teenager Reason Man skewer ``1 sum husband 1 other person 1

Claims (8)

[Claims] (1) Zn: 5 to 25%, one or more of Fe, Ni, and Co: 0
．． 1 to 3%, oxygen: 0.01 to 0.5%, and the rest is Cu and unavoidable impurities (weight%), and fine oxides and intermetallic compounds are uniformly distributed in the matrix. A copper-based sintered alloy having excellent wear resistance at high temperatures and having a structure in which pores are dispersed and distributed at 1 to 15% by volume. (2) Zn: 5 to 25%, one or more of Fe, Ni, and Co: 0
．． 1 to 3%, oxygen: 0.01 to 0.5%, and further contains Al: 0.1 to 0.3%, with the remainder consisting of Cu and unavoidable impurities (more than 1% by weight) ), and a copper-based sintered bond with excellent wear resistance at high temperatures, characterized by having a structure in which fine oxides and intermetallic compounds are uniformly dispersed in the matrix and pores are distributed at 1 to 15% by volume. Money. (3) Zn: 5-25%, one or more of Fe, Ni, and Co: 0
．． 1 to 3%, oxygen: 0.01 to 0.5%, and further contains Mn: 0.1 to 3%, with the remainder consisting of Cu and unavoidable impurities (wt%), and a copper-based sintered alloy with excellent wear resistance at high temperatures, characterized by having a structure in which fine oxides and intermetallic compounds are uniformly dispersed in the matrix and pores are distributed at 1 to 15% by volume. (4) Zn: 5 to 25%, one or more of Fe, Ni, and Co: 0
．． 1 to 3%, oxygen: 0.01 to 0.5%, and further contains one or more of Cr, Mo, and W: 0.
1 to 2%, with the remainder being Cu and unavoidable impurities (wt%), and fine oxides and intermetallic compounds are uniformly dispersed in the matrix, and pores are 1 to 15% by volume. A copper-based sintered alloy with excellent wear resistance at high temperatures, characterized by a distributed structure. (5) Zn: 5 to 25%, one or more of Fe, Ni, and Co: 0
．． 1 to 3%, oxygen: 0.01 to 0.5%, and further contains Al: 0.1 to 0.3%, Mn: 0.1 to 3%, and the remainder is Cu and High-temperature resistant, characterized by a composition consisting of unavoidable impurities (more than 1% by weight) and a structure in which fine oxides and intermetallic compounds are uniformly dispersed in the matrix and pores are distributed 1 to 15% by volume. Copper-based sintered alloy with excellent wear resistance. (6) Zn: 5 to 25%, one or more of Fe, Ni, and Co: 0
．． 1 to 3%, oxygen: 0.01 to 0.5%, and further contains: Al: 0.1 to 0.3%, and one or more of Cr, Mo, and W: 0.
1 to 2%, with the remainder being Cu and unavoidable impurities (wt%), and fine oxides and intermetallic compounds are uniformly dispersed in the matrix, and pores are 1 to 15% by volume. A copper-based sintered alloy with excellent wear resistance at high temperatures, characterized by a distributed structure. (7) Zn: 5 to 25%, one or more of Fe, Ni, and Co: 0
．． 1 to 3%, oxygen: 0.01 to 0.5%, and further contains Mn: 0.1 to 3%, one or more of Cr, Mo, and W: 0.
1 to 2%, with the remainder being Cu and unavoidable impurities (wt%), and fine oxides and intermetallic compounds are uniformly dispersed in the matrix, and pores are 1 to 15% by volume. A copper-based sintered alloy with excellent wear resistance at high temperatures, characterized by a distributed structure. (8) Zn: 5 to 25%, one or more of Fe, Ni, and Co: 0
．． 1 to 3%, oxygen: 0.01 to 0.5%, and further contains Al: 0.1 to 0.3%, Mn: 0.1 to 3%, Cr, Mo, and W. One or more types: 0.
1 to 2%, with the remainder being Cu and unavoidable impurities (wt%), and fine oxides and intermetallic compounds are uniformly dispersed in the matrix, and pores are 1 to 15% by volume. A copper-based sintered alloy with excellent wear resistance at high temperatures, characterized by a distributed structure.