JP2697171B2 - Copper-based sintered alloy with excellent wear resistance at high temperatures - Google Patents

Description

The present invention relates to a copper-based sintered alloy having excellent wear resistance under any conditions from room temperature to high temperature, and particularly to wear resistance under high temperature. The present invention relates to an excellent copper-based sintered alloy, and more particularly to a copper-based sintered alloy suitable for use as a guide bush of an internal combustion engine, a bearing of a turbocharger, and the like.

[Conventional technology]

Conventionally, the weight% (hereinafter% is
%), A copper-based ingot alloy or an iron-based sintered alloy having a typical composition of Cu-28% Zn-6% Al is used. In particular, the guide bush is made of an iron-based sintered alloy. Was used.

[Problems to be solved by the invention]

However, when the above-mentioned conventional copper-based alloys and iron-based sintered alloys are used at a relatively low temperature to a high temperature, seizure occurs at a high temperature and there is a problem in wear resistance.

Recent internal combustion engines have been exposed to higher temperatures in sliding parts than ever before with the increase in output. Therefore, there has been a strong demand for the development of a copper-based alloy that does not cause seizure even at high temperatures and has excellent wear resistance, as well as wear resistance at room temperature.

[Means for solving the problem]

In view of the above, the present inventors have conducted research to develop a copper-based sintered alloy having more excellent seizure resistance and wear resistance. As a result, Sn: 1 to 5%, Mn : 0.1 to 3%, Si: 0.1 to 2%, oxygen: 0.01 to 0.5%, and if necessary, (a) one or more of Cr, Mo, and W: 0.1
(B) one or more of Fe, Ni, and Co: 0.1
(C) Al: 0.1 to 0.3%, a composition containing any one or more of the above (a) to (c), and the remainder consisting of Cu and unavoidable impurities, and A copper-based sintered alloy having a structure in which fine oxides and intermetallic compounds are uniformly dispersed and pores are distributed in a volume ratio of 0.5 to 10 has improved wear resistance at room temperature and high temperature, and It has been found that the presence of fine oxides and pores improves the seizure resistance at high temperatures.

The present invention has been made on the basis of such findings, and the copper-based sintered alloy of the present invention has, according to the above composition, 0.1 to 7 oxides distributed in a particle size range of 1 to 40 μm in the base material. % And uniformly dispersed in the same area ratio of 1-2%
1 to 8% of intermetallic compounds distributed within a particle size range of 5 μm
Uniformly distributed at an area ratio of 1 to 40 μm, and pores within a particle size range of 1 to 40 μm have a uniformly distributed structure of 0.5 to 10% by volume,
The presence of these oxides and intermetallic compounds in the substrate significantly improves the wear resistance at room temperature and high temperatures, and the presence of these oxides and vacancies in the substrate reduces the seizure resistance at high temperatures. This is a significant improvement.

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

(A). Voids Voids are distributed on the sliding surface and have the effect of improving seizure resistance, especially at high temperatures. However, if less than 0.5% by volume, the effect cannot be obtained, while if more than 10% by volume, Not only the strength is reduced, but also the heat conductivity is lowered due to the lowered thermal conductivity, the seizure resistance at high temperatures is lowered, and the wear resistance is also lowered.

Therefore, the distribution amount of vacancies is set to 0.5 to 10% by volume.

(B). Sn Sn forms a base together with Cu and has the effect of strengthening the base and improving the adhesion resistance. However, if it is less than 1%, the desired effect is not obtained. In addition, the toughness is reduced, and the seizure resistance is reduced due to the deterioration of the heat resistance.

 Therefore, the content of Sn is set to 1 to 5%.

(C). Mn and Si These components combine with each other to form an intermetallic compound that is finely dispersed in the base material, thereby improving wear resistance, seizure resistance and strength. , Mo, or Cr
In addition to forming a hard and fine intermetallic compound by bonding with oxygen, it also forms a double oxide by bonding with oxygen, and has an effect of further improving wear resistance and seizure resistance. Less than 0.1% each has no effect,
On the other hand, if the content of Mn exceeds 3%, and the content of Si exceeds 2%, on the contrary, the seizure resistance decreases and the attacking property of the opponent increases, which is not preferable.

Therefore, the content of Mn is set to 0.1 to 3%, and the content of Si is set to 0.1 to 2%.

(D). Oxygen combines with Cu, Mn, and Si, and optionally contained Al, W, Mo, and Cr, to form oxides that are uniformly and finely dispersed in the matrix, Has the effect of improving the abrasion resistance at high temperatures, and in particular, the seizure resistance and the abrasion resistance at high temperatures. However, if it is less than 0.01%, it has no effect. Particle size 4
In addition to coarsening exceeding 0 μm, the area ratio is 7%
, The strength and toughness of the alloy are lowered, and the aggressiveness of the alloy is increased, which is not preferable.

Therefore, the content of oxygen was set to 0.01 to 0.5%.

(E). W, Mo, and Cr All of these components are dispersed in the base material to improve the strength, and furthermore, Si and Fe, Ni,
Combines with Co and Co to form a fine intermetallic compound, and also forms a fine oxide by combining with oxygen, which has the effect of improving abrasion resistance and seizure resistance. If the amount is less than 0.1%, the desired effect cannot be obtained. On the other hand, if the content exceeds 2%, the toughness decreases, which is not preferable.

Therefore, the contents of W, Mo, and Cr are set to 0.1 to 2%.

(F). Fe, Ni, and Co All of these components are dispersed in the base material to improve the strength and toughness of the alloy, and also contain Cu and, if necessary, Al, W, Mo, and Cr contained therein. Combines with to form a fine intermetallic compound dispersed in the substrate, which has the effect of improving abrasion resistance and improving seizure resistance,
If the content is less than 0.1%, the desired effect cannot be obtained,
On the other hand, if the content exceeds 3%, the toughness decreases, which is not preferable.

Therefore, the content of Fe, Ni, and Co is 0.1-3%
Determined.

(G). Al Al combines with oxygen to form an oxide, which has the effect of improving abrasion resistance and anti-seizure properties at high temperatures. However, if the content is less than 0.1%, the desired effect is obtained. On the other hand, if the content exceeds 0.3%, the toughness is reduced due to the coarsening of the oxide and the increase in the amount of the oxide, and the aggressiveness of the partner is further increased.

 Therefore, the content of Al is set to 0.1 to 0.3%.

The copper-based sintered alloy of the present invention may contain P, Mg, Zn, and Pb as unavoidable impurities, but if the total content is 1.5% or less, the alloy characteristics are impaired at all. It is not acceptable, so its content is acceptable.

〔Example〕

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

As raw material powder, Cu-3% S, all less than 200mesh
n alloy powder, Cu-9% Sn alloy powder, Cu powder, Sn powder, Al
Powder, Si powder, Mo powder, W powder, Cr powder, Fe powder, Ni powder, and Co powder are prepared, and these raw material powders are blended.
After powder mixing with a V-type mixer for 3 hours, 5-7ton / cm ²
Press molding into a green compact at a predetermined pressure within the range of
Sintering is carried out at a predetermined temperature within a range of 600 to 850 ° C. for 1 hour in a hydrogen gas at a temperature of -30 ° C. to −30 ° C., and then 300 to 500 ° C. as needed to control the amount of vacancies. After holding for 1 minute at a predetermined temperature within the range, by re-pressurizing, it has dimensions of outer diameter: 70 mm, inner diameter: 63 mm, thickness: 12 mm for crush load measurement. Inventive Cu-based sintered alloys 1-44 consisting of rings having the composition shown, and comparison
A round bar having a diameter of 10 mm, a height of 30 mm and a pipe having an outer diameter of 12 mm, an inner diameter of 6 mm, and a length of 45 mm were used for measuring wear of the Cu-based sintered alloys 1 to 15. Inventive Cu-based sintered alloys 1 to 44 and Comparative Cu-based sintered alloys 1 to 15 were produced, respectively.

Furthermore, a conventional Cu-based alloy made of a ring, a round bar and a pipe having the above dimensions was produced by melting and casting by a usual melting method.

Each of the Cu-based sintered alloys 1 to 44 of the present invention had a structure in which fine oxides and intermetallic compounds were uniformly dispersed in the base material.

Each of the comparative Cu-based sintered alloys 1 to 15 has a content of any one of the constituent components or a vacancy content (first content).
Those marked with * in the table) are out of the scope of the present invention.

Next, for the various Cu-based sintered alloys obtained as a result, the above ring was divided into three parts for the purpose of evaluating the strength and toughness, and one of the rings was used as a sample to measure the crushing load at room temperature. The following abrasion test was conducted for the purpose of evaluating the abrasion resistance at a high temperature shown in Table 1 and further.

Abrasion test I A round rod having a diameter of 10 mm and a height of 30 mm was processed into a pin having a diameter of 1.5 mm, and a chrome-plated SUH disk was prepared as a mating member. Rotate the disc from the back side at a peripheral speed of 1.8 m / sec while heating the disc to 510 ° C with a burner.On the other hand, press the pin against the disc with a pressing load of 7 kg and slide while dropping 5W-30 oil. Distance: Slide 15km, conduct a pin-on-disk friction and wear test to evaluate the synchronization characteristics of the mating material at high temperatures, and investigate the occurrence of seizure from the change in the generated torque using a torque meter. The results are shown in Table 1.

Abrasion test II Each of the Cu-based sintered alloys of the present invention, comparative Cu-based sintered alloys and conventional Cu-based smelted alloys each consisting of pipes having the above outer diameter: 12 mm, inner diameter: 6 mm, and length: 45 mm Outside diameter: 1
Samples of various Cu-based sintered alloys of the present invention, comparative Cu-based sintered alloys and conventional Cu-based smelted alloys, each of which is composed of a pipe having dimensions of 1 mm, an inner diameter of 6.2 mm, and a length of 45 mm, were manufactured. SUH material was subjected to salt bath nitriding treatment A round bar having a diameter of 6.1 mm and a length of 150 mm was prepared.

Insert the round bar as the mating material into the pipe hole as the sample, heat one end of the round bar as the mating material with a burner, set the ambient temperature at one end to 440 ° C, and press the sample against the mating material. : Press with 5kg, while dropping 5W-30 oil,
Stroke the round bar, which is the mating material, in the axial direction of the pipe hole, which is the sample, at a sliding distance of 12 mm and 4000 strokes / min.
Perform a wear test under the condition of 0 minute sliding, measure the amount of wear,
Furthermore, observe the presence or absence of seizure and the surface condition of the mating material,
The results are shown in Table 1.

In addition, the surface condition of the mating member was distinguished by adding a circle to a surface having no scratch on the surface, a triangle to a partially scratched surface, and a cross to a worn scratch.

〔The invention's effect〕

From the results shown in Table 1, the Cu-based sintered alloys of the present invention 1 to
No. 44 has much higher abrasion resistance and seizure resistance than the conventional Cu-based ingot alloy, and as shown in Comparative Cu-based sintered alloys 1 to 15, If any one of them is out of the range of the present invention, at least one of the properties of abrasion resistance at a high temperature, seizure resistance or aggression to a partner, or strength and toughness at a normal temperature is inferior. Is evident.

As described above, the Cu-based sintered alloy of the present invention has abrasion resistance and synchronization characteristics at high temperatures, so that it can be adequately used as a structural member of various devices exposed to high temperatures accompanying high output. In practical use, it exhibits excellent industrial performance by exhibiting excellent performance over a long period of time.

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Claims (8)

(57) [Claims] 1. A composition comprising: Sn: 1 to 5%, Mn: 0.1 to 3%, Si: 0.1 to 2%, oxygen: 0.01 to 0.5%, and the balance consisting of Cu and inevitable impurities (at least by weight%). ) And a copper-based sintering bond having excellent wear resistance at high temperatures, characterized by having a structure in which fine oxides and intermetallic compounds are uniformly dispersed in the substrate and pores are distributed in a volume of 0.5 to 10% by volume. Money. 2. An alloy containing: Sn: 1 to 5%, Mn: 0.1 to 3%, Si: 0.1 to 2%, oxygen: 0.01 to 0.5%, and one or more of Cr, Mo, and W or Two or more: 0.1 to 2%, with the balance being Cu and unavoidable impurities (more than% by weight), and fine oxides and intermetallic compounds uniformly dispersed in the base material and pores of 0.5% or less. A copper-based sintered alloy having excellent wear resistance at high temperatures, characterized by having a structure distributed up to 10% by volume. (3) Sn: 1 to 5%, Mn: 0.1 to 3%, Si: 0.1 to 2%, Oxygen: 0.01 to 0.5%, and one or more of Fe, Ni, and Co or 2 or more: 0.1 to 3%, the balance being Cu and unavoidable impurities (more than weight%), and fine oxides and intermetallic compounds uniformly dispersed in the base material and vacancies of 0.5% A copper-based sintered alloy having excellent wear resistance at high temperatures, characterized by having a structure distributed up to 10% by volume. 4. An alloy comprising: Sn: 1 to 5%, Mn: 0.1 to 3%, Si: 0.1 to 2%, oxygen: 0.01 to 0.5%, and Al: 0.1 to 0.3%. The remainder is composed of Cu and inevitable impurities (more than weight%), and has a structure in which fine oxides and intermetallic compounds are uniformly dispersed in the matrix and pores are distributed in a volume of 0.5 to 10% by volume. Copper-based sintered alloy with excellent wear resistance at high temperatures. 5. An alloy containing: Sn: 1 to 5%, Mn: 0.1 to 3%, Si: 0.1 to 2%, oxygen: 0.01 to 0.5%, and one or more of Cr, Mo, and W or 2 or more: 0.1 to 2%, one or more of Fe, Ni, and Co: 0.1 to 3%, the balance being Cu and unavoidable impurities (more than weight%) A copper-based sintered alloy having excellent wear resistance at high temperatures, characterized by having a structure in which fine oxides and intermetallic compounds are uniformly dispersed therein and pores are distributed in a volume of 0.5 to 10% by volume. 6. Sn: 1 to 5%, Mn: 0.1 to 3%, Si: 0.1 to 2%, Oxygen: 0.01 to 0.5%, and one or more of Cr, Mo, and W or 2 or more: 0.1 to 2%, Al: 0.1 to 0.3%, with the balance being Cu and unavoidable impurities (more than weight%), and fine oxides and intermetallic compounds in the matrix uniformly A copper-based sintered alloy having excellent wear resistance at high temperatures, characterized by having a structure in which pores are dispersed and pores are distributed in a volume of 0.5 to 10% by volume. 7. Sn: 1 to 5%, Mn: 0.1 to 3%, Si: 0.1 to 2%, oxygen: 0.01 to 0.5%, and one or more of Fe, Ni, and Co or 2 or more: 0.1 to 3%, Al: 0.1 to 0.3%, the balance being Cu and unavoidable impurities (more than weight%), and fine oxides and intermetallic compounds in the substrate uniformly A copper-based sintered alloy having excellent wear resistance at high temperatures, characterized by having a structure in which pores are dispersed and pores are distributed in a volume of 0.5 to 10% by volume. 8. An alloy containing: Sn: 1 to 5%, Mn: 0.1 to 3%, Si: 0.1 to 2%, oxygen: 0.01 to 0.5%, and one or more of Cr, Mo, and W or 2 or more: 0.1 to 2%, one or more of Fe, Ni, and Co: 0.1 to 3%, Al: 0.1 to 0.3%, the balance being Cu and inevitable impurities ( Copper having 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 in a range of 0.5 to 10% by volume. Base sintered alloy.