JP2017082328A - Copper alloy for slide member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copper alloy for a slide member having better slidability than conventional ones.SOLUTION: The copper alloy for a slide member contains Sn of 3.0 mass% to 16.0 mass%, S of 3.0 mass% to 15.0 mass% and the balance copper with inevitable impurities.SELECTED DRAWING: None

Description

  The present invention relates to a copper alloy used for a sliding surface of a sliding member. In particular, the present invention relates to a copper alloy for sliding members that does not contain lead as a main component.

  Conventionally, a copper alloy containing lead represented by CAC603 (Cu—Sn—Pb-based copper alloy) has been used for a sliding member having a sliding portion such as a bearing. In these alloys, lead greatly contributes to slidability and good sliding characteristics can be obtained. However, in order to meet social demands to suppress the use of lead, various copper alloys for sliding materials that suppress the use of lead have been studied.

  For example, in Patent Document 1 concerning a copper alloy for sliding members, as an example, Fe is 0.31 to 3.43 mass%, S is 0.42 to 1.04 mass%, and Sn is 5.14 to 15%. An example of a sliding member containing 0.54% by mass, 0.012 to 0.02% by mass or less of P, and the balance being copper and inevitable impurities is given. Further, as Comparative Example 6, the same document contains 12.15% by mass of Fe, 10.27% by mass of Sn, 2.21% by mass of S, 0.028% by mass of P, and the balance is inevitable with copper. Copper alloys, which are potential impurities, are described. However, this Comparative Example 6 is a test result having a problem in wear because of too much Fe.

Moreover, in patent document 2 about a lead-free copper alloy sliding material, as comparative example 3, Sn is 5 mass%, MoS ₂ is 5 mass%, CuS is 0.75 mass%, and MoO ₃ is 1.5 mass. A copper alloy containing% and containing no Pb is shown. The content of each element in Comparative Example 3 is approximately 2.25% by mass for S, approximately 4% by mass for Mo, and approximately 0.5% by mass for O by simple calculation. However, since Comparative Example 3 does not contain Pb, the test result is easy to be burned.

  Further, in Patent Document 3 regarding the Pb-free copper alloy composite sliding material, as Example 1, a copper alloy containing 5% by mass of Sn, 1% by mass of Ag, and 1% by mass of CuS is shown. The content of S contained in this is about 0.33 mass% by simple calculation.

  In addition, in patent document 4 regarding a copper alloy tube, a copper alloy containing 5 to 25 ppm of S in addition to Sn is disclosed. In the examples of this document, there is a description that 5 to 85 units of S are contained in the components described in Table 1-1 in which each element is represented by mass%. However, it is obvious from the specification [0019] that S is 0.0005% by mass or less, and from the upper limit in the table, it is in ppm rather than%.

Japanese Patent No. 4658269 Japanese Patent No. 4427410 Japanese Patent No. 4757460 JP 2013-189664 A

  However, although the various copper alloys shown in the examples of Patent Documents 1 and 3 all exhibit a certain level of slidability, there is a need for a copper alloy that exhibits even greater slidability in practice. became.

Further, in the copper alloy described in Patent Document 2, which exhibits a sliding property by containing MoS _2, it presupposes the existence of Mo. However, Mo is relatively expensive compared to Fe, Cu, and Sn, and a low-cost copper alloy that does not include Mo is demanded.

  Furthermore, the copper alloy described in Patent Document 4 has an extremely small S content as compared with the copper alloys described in Patent Documents 1 to 3, and thus cannot practically exhibit sliding performance.

  Therefore, an object of the present invention is to provide a copper alloy for a sliding member that does not contain an extra element and has better slidability than conventional ones.

  According to a copper alloy for a sliding member containing 3.0 mass% or more and 16.0 mass% or less of Sn, 3.0 mass% or more and 15.0 mass% or less of S, and the balance being copper and inevitable impurities The above problem has been solved.

  That is, the feature of the copper alloy for sliding members according to the present invention is that Sn is adjusted to an appropriate amount and the S content is made extremely higher than conventional common sense.

  According to the present invention, it is possible to exhibit higher sliding performance than conventional copper alloys for sliding members while keeping the cost required for manufacturing the alloy low.

Configuration diagram of the ball-on-disk test used in the examples Schematic diagram of holder

  The present invention will be described in detail below. The present invention is a copper alloy for a sliding member used for a sliding surface of a sliding member.

  The copper alloy for sliding members according to the present invention needs to contain Sn of 3.0% by mass or more. Sn has an effect of improving the matrix strength of the copper alloy, improving wear resistance and corrosion resistance, and maintaining good sliding characteristics. However, these effects are insufficient when the content is less than 3.0% by mass. End up. On the other hand, the Sn content needs to be 16.0% by mass or less. If it exceeds 16.0% by mass, the mating material may be remarkably worn and good sliding characteristics may not be obtained.

  The copper alloy for sliding members needs to contain S in an amount of 3.0% by mass or more, preferably 4% by mass or more, and more preferably 5% by mass or more. In the copper alloy, S exists as a sulfide combined with Cu or Fe (when contained), and these sulfides contribute to the slidability. In the above-mentioned copper alloy for sliding members according to the present invention, the amount of sulfide in the alloy is conventionally determined to be unsuitable by containing S more than the range that can be produced by conventional common sense. To improve the slidability. On the other hand, the S content needs to be 15.0% by mass or less, and is preferably 14.0% by mass or less. This is because if it exceeds 15.0% by mass, a problem tends to arise in the mechanical properties required for the sliding member in addition to the slidability.

  When manufacturing the above-mentioned copper alloy for sliding members, it is difficult to manufacture by simply mixing a single S and melting it, but a compound having a high S content was previously generated with S and other elements. Thereafter, a copper alloy having S at a higher ratio than conventional can be obtained by producing a copper alloy using this compound. Specifically, for example, a molten alloy of a copper alloy containing a large amount of S is sprayed and rapidly cooled to obtain an atomized powder containing a large amount of S, and the atomized powder is sintered and manufactured. S may or may not contain S), and sulfide powder such as copper sulfide, iron sulfide, tin sulfide, or simple sulfur powder, or a powder obtained by mixing two or more of them. A method of sintering the mixed powder after mixing and the like can be mentioned. However, a manufacturing method is not limited to these, What is necessary is just to be able to manufacture as a copper alloy, even if content of S which occupies for the whole exceeds 3.0 mass%.

  The said copper alloy for sliding members may contain Fe. Fe forms a sulfide together with Cu and contributes to slidability. Although it is considered that even if it is above the detection limit, it is considered that the effect is exerted little by little. However, in order to sufficiently exhibit the effect of contributing to the slidability, it is preferable that Fe is contained in an amount of 0.3% by mass or more, and 0.5% by mass. It is more preferable to contain at least%. On the other hand, if Fe is contained in excess of 15.0% by mass, the performance as a sliding member may be greatly deteriorated. Therefore, it is preferably 15.0% by mass or less, and 14.0% by mass or less. More preferred.

  The copper alloy for sliding members may contain P. When P is contained in excess of the detection limit, the effect of deoxidizing the molten copper alloy is exhibited according to the amount. Furthermore, when sintering the powder produced by the atomization method, if the impurities present at the boundaries of the powder particles to be sintered together are reduced by deoxidation, there will be less obstacles during sintering, so the sintering density The effect which improves is demonstrated. In order to fully exhibit these effects, it is good to contain 0.01 mass% or more. On the other hand, when it contains exceeding 0.3 mass%, since there exists a possibility of inhibiting the performance as a sliding member, it is preferable in it being 0.3 mass% or less.

  The said copper alloy for sliding members is good in it being copper and an unavoidable impurity other than said element. The smaller the content of elements contained as the inevitable impurities, the better. Examples of such elements include Mo.

Example 1
The powder produced by the atomization method was adjusted so that Sn was 10% by mass, S was 4.2% by mass, Fe was 3.2% by mass, P was 0.02% by mass, and the balance was copper and inevitable impurities. It was sprayed on the steel plate. The steel sheet was sintered together with the powder at 850 ° C. for 20 minutes. The steel sheet after the primary sintering was rolled with a rolling mill and then subjected to secondary sintering at 850 ° C. for 10 minutes. In addition, the thickness of the copper alloy layer after the secondary sintering was 65% with respect to the dispersion thickness of the powder produced by the atomization method. The copper alloy surface after the secondary sintering is polished and finished in a mirror state is used as a test material.

  A 3ball on disc test was performed on the disk 11 made of this test material. A schematic diagram of a specific test is shown in FIGS. Three balls 12 made of high carbon chrome bearing steel (SUJ2) as the counterpart material are set in the ball holes 13a of the holder 13 so as to be evenly arranged at an angle of 120 degrees on a circle having a diameter of 33.5 mm. . The ball 12 was adjusted so that the contact surface with respect to the disk 11 was φ1.5 mm, a load with a surface pressure of 1.9 MPa was applied, and the ball was rotated so that the sliding speed of the ball was 1 m / s. In particular, no lubricating oil is used. The speed until the disc surface was burned was measured, and when it was not burned, the race was completed at 1000 m, and both races were completed in two tests.

(Comparative Example 1)
A copper alloy plate adjusted so that Sn was 10% by mass, S was 0.6% by mass, Fe was 0.1% by mass, P was 0.02% by mass, and the balance was copper and inevitable impurities was cast. When the surface of this copper alloy plate was finished in a mirror state was used as a test material, and the 3ball on disc test was performed twice in the same manner as in Example 1, the average burn-in distance was 44.5 m, and burned out quickly. .

(Comparative Example 2)
A copper alloy plate adjusted so that Sn was 10 mass%, P was 0.2 mass%, and the balance was copper and inevitable impurities was cast. When the surface of this copper alloy plate was finished in a mirror state as a test material, the 3ball on disc test was performed twice in the same manner as in Example 1. As a result, the average burn-in distance was 18 m, and the image burned out quickly.

(Example 2)
The test material was prepared in the same procedure as in Example 1 except that Sn was adjusted to 10.1% by mass, S to 3.5% by mass, Fe to 3.5% by mass, and the balance to be copper and inevitable impurities. Obtained. In the 3ball on disc test, schematic diagrams are as shown in FIGS. However, in order to confirm the performance in the environment where the lubricating oil is present, the ball 12 is adjusted so that the contact surface of the ball 11 with respect to the disk 11 is 1.0 mm, and the friction speed is 2.0 m / s and the friction distance is 100 m The lubricating oil was applied in an amount of 1.0 g in advance to the portion of the disk 11 in contact with the ball 12 using a base oil, and a friction test was performed.

  First, after sliding preliminarily for 500 m at a surface pressure of 8.4 MPa and a surface pressure of 12.6 MPa, a 250 m test was performed at 20.9 MPa. In this case, the test was continued until seizure occurred by increasing the load by about 8.3 MPa every 250 m, such as 250 m at 37.5 MPa, and the surface pressure (MPa) at which seizure occurred. The slidability was evaluated by the sliding distance (m). The results are shown in Table 2.

(Comparative Example 3)
Example 1 except that Sn was adjusted to 10.2% by mass, S 1.0% by mass, Fe 0.8% by mass, P 0.03% by mass, and the balance being copper and inevitable impurities. And the test material was obtained by the same procedure as 2. Table 2 shows the results of a 3ball on disc test performed on this test material in the same manner as in Example 2. When Example 2 and Comparative Example 3 were compared, it was confirmed that Example 2 exhibited significantly superior sliding performance.

11 Disc 12 Ball 13 Holder 13a Ball hole 14 Disc retainer 15 Jig

Claims (5)

  A copper alloy for a sliding member containing Sn in an amount of 3.0 to 16.0% by mass, S in an amount of 3.0 to 15.0% by mass, and the balance being copper and inevitable impurities.   Sn is contained in an amount of 3.0% by mass or more and 16.0% by mass or less, S is contained in an amount of 3.0% by mass or more and 15.0% by mass or less, Fe is contained in a detection limit or more and 15.0% by mass or less, and the remainder is inevitable with copper. Copper alloy for sliding members, which is a typical impurity.   Sn is contained in an amount of 3.0% by mass or more and 16.0% by mass or less, S is contained in an amount of 3.0% by mass or more and 15.0% by mass or less. Copper alloy for sliding members, which is a typical impurity.   Sn is not less than 3.0% by mass and not more than 16.0% by mass, S is not less than 3.0% by mass and not more than 15.0% by mass, Fe is not less than the detection limit and not more than 15.0% by mass, P is not less than the detection limit and is 0.3 A copper alloy for sliding members which is contained by mass% or less and the balance is copper and inevitable impurities. A method for producing a copper alloy for a sliding member containing Sn of 3.0% by mass or more and 16.0% by mass or less and S of 3.0% by mass or more and 15.0% by mass or less,
A copper alloy powder containing Sn, and one or more of copper sulfide, iron sulfide, tin sulfide sulfide powder and single sulfur powder are mixed and sintered to form an integrated slide. A method for producing a copper alloy for sliding members, comprising obtaining a copper alloy for moving members.

Images