JPH06220555A - Sliding contact material and its production - Google Patents

Abstract

PURPOSE:To produce a sliding contact material where wear resistance is improved and the formation of wear particle is reduced and the occurrence of noise is prevented. CONSTITUTION:This material is a sliding contact material containing 0.1-8wt.% Cu, in which >=70wt.% of the total Cu content is allowed to enter into solid solution in Agalpha-phase and further at least one or more elements selected from Ge, Ni, Sn, In, Zn, Mg, Mn, Sb, Pb, and Bi are contained by 0.1-2wt.%. The sliding contact material is subjected to holding at a temp. in the range not higher than the solidus temp. in the AgCu binary constitutional diagram of the composition and not lower than the solubility curve temp., to rapid cooling, and then to cold working at >=30% draft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding contact material and a processing method thereof, and more particularly to a commutator material and a processing method suitable for a micromotor.

[0002]

2. Description of the Related Art Ag has been conventionally used as one of sliding contact materials.
A Cu alloy has been used, but the metal structure of the AgCu alloy is not sufficiently controlled, and in particular, the Cu atom is not completely solid-solved in the Agα phase, and solid solution hardening is not sufficiently exerted. It was Therefore, it was softened at the time of sliding due to the variation of the metal structure at the time of manufacturing, was worn quickly, and had insufficient wear resistance. Further, in the case of a micromotor in which a commutator is made of this material, abrasion occurs due to sliding with the brush contact, and abrasion powder causes noise.

[0003]

SUMMARY OF THE INVENTION Therefore, the present invention is intended to provide a sliding contact material having improved wear resistance, reduced generation of abrasion powder and suppressed generation of noise, and a method of processing the same. Is.

[0004]

One of the sliding contact materials of the present invention for solving the above-mentioned problems is an AgCu alloy containing 0.1 to 8% by weight of Cu.
It is characterized in that 70% by weight or more is solid-dissolved in the Agα phase.

Another one of the sliding contact materials of the present invention is the above sliding contact material, further comprising Cd, Pb, Ge and I.
It is characterized by containing 0.1 to 2% by weight of at least one kind selected from n, Sn, Sb and Zn.

In the method for producing a sliding contact material of the present invention, one of the above two sliding contact materials is used in the composition A
It is characterized in that the temperature is kept below the solidus temperature and above the solubility curve temperature in the gCu binary system phase diagram, followed by rapid cooling and then cold working at a working rate of at least 30% or more.

[0007]

As described above, the sliding contact material of the present invention is Agα
Since 70% by weight or more of the total amount of Cu is dissolved in the phase,
It is possible to sufficiently exert solid solution hardening to the gα phase,
It is possible to reduce wear caused by softening that occurs during sliding and improve wear resistance. Here, C which forms a solid solution in the Agα phase
The reason why the amount of u is 70% by weight or more is that if it is less than this, the solid solution curing cannot be sufficiently exhibited.

Further, the above sliding contact materials are Ge, Ni,
Sn, In, Zn, Mg, Mn, Sb, Pb and Bi
By containing at least one selected from the range of 0.1 to 2% by weight, the effect of reducing wear is further improved. The content range is 0.1 to 2% by weight. If the content is less than 0.1% by weight, the effect of reducing wear cannot be exhibited, and if it exceeds 2% by weight, the contact resistance becomes too high. This is because.

In the method for producing a sliding contact material according to the present invention, the solution treatment by heating is performed and then the cold working is performed. If the solution treatment is still performed, the Agα phase is recrystallized and softened. This is because, if the press working is performed as it is, a problem that unevenness occurs on the surface occurs. As in the method for producing a sliding contact material of the present invention, after the solution treatment, by performing cold working at a working rate of at least 30% or more, to suppress surface irregularities generated by work hardening and press working,
Further, the wear resistance can be improved. The sliding contact material of the present invention produced in this way has a significantly improved wear resistance. The noise caused by the powder can be reduced.

[0010]

EXAMPLES Examples of the sliding contact material of the present invention and a method for producing the same will be described together with comparative examples and conventional examples. The material of Example 1 having the component composition shown in Table 1 below was held at 750 ° C. for 1 hour, cooled with water, and then wire-drawn at a working rate of 49%. The materials of Examples 2-12 and Comparative Examples 1-2 were 700 ° C.
After being held for 30 minutes at 80 ° C., it was cooled with water and then drawn at a working rate of 75%. The material of the conventional example is 1 at 550 ° C.
After holding for a time, it was air-cooled, and then wire drawing was performed at a working rate of 49%.

[0011]

[Table 1]

The Agα phase lattice constant of the material thus manufactured was 4.037Å in Example 1, 4.050Å in Example 2,
It was 4.063Å in the conventional example. According to Vegard's law, the solid solution amounts of Cu in Examples 1, 2 and the conventional example are 6.6% by weight, 4.8% by weight and 3% by weight, respectively, and 88% by weight of the total amount of Cu contained in the sliding contact material, respectively. , 80 wt% and 40 wt% were in solid solution in the Agα phase.

As a test material for Examples 1 to 12, Comparative Examples 1 and 2 and the conventional example having the above-mentioned composition, a round bar having a diameter of 2 mm was used and crossed with a round bar having the same diameter of 50% Ag-Pd.
A sliding test was conducted under the following test conditions to determine the amount of wear and the contact resistance, and the results shown in Table 2 below were obtained.

Test conditions Current DC 170mA Sliding speed 20mm / sec Load 25g Test time 333 minutes Temperature 25 ° C Humidity 50% RH

[0015]

[Table 2]

As can be seen in Table 2 above, Examples 1-12
It can be seen that the sliding contact material of (1) has a significantly smaller amount of wear than the sliding contact material of the conventional example, and the contact resistance is significantly low. Further, the sliding contact material of Comparative Example 1 has a large amount of wear in spite of low contact resistance, and Comparative Example 2 has a problem of high contact resistance in spite of a small amount of wear. It is inferior to the material.

[0017]

As described above, the sliding contact material of the present invention is Ag
70% or more of the Cu atoms contained in the α phase are dissolved,
Furthermore, Ge, Ni, Sn, In, Zn, Mg, Mn, S
It contains at least one of b, Pb and Bi, and can sufficiently exhibit solid solution hardening to the Agα phase. Therefore, it is possible to reduce wear caused by softening that occurs during sliding and improve wear resistance. Further, the Agα phase is recrystallized and softened when the solution treatment is performed, but cold working should be performed at a working rate of at least 30% or more as in the working method of the sliding contact material of the present invention. Work hardens by. Therefore, the sliding contact made of this material is reduced in abrasion when sliding on the brush contact, and noise caused by abrasion can be reduced.

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[Procedure amendment]

[Submission date] June 7, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

Another one of the sliding contact materials of the present invention is the above sliding contact material, further comprising Ge, Ni, Sn and I.
It is characterized by containing 0.1 to 2% by weight of at least one selected from n, Zn, Mg, Mn, Sb, Pb and Bi .

Claims (4)

[Claims] 1. AgC containing 0.1 to 8% by weight of Cu
In the u alloy, a sliding contact material comprising 70% by weight or more of the total amount of Cu contained in the Agα phase as a solid solution. 2. The sliding contact material further comprising G
e, Ni, Sn, In, Zn, Mg, Mn, Sb, Pb
2. The sliding contact material according to claim 1, containing 0.1 to 2% by weight of at least one selected from Bi and Bi. 3. AgC containing 0.1 to 8% by weight of Cu
The u alloy should be cooled at a temperature below the solidus temperature and above the solubility curve temperature in the AgCu binary phase diagram for that composition, followed by quenching and then cold working at a working rate of at least 30% or more. A method for producing a sliding contact material characterized. 4. The AgCu alloy further comprises Ge, N
i, Sn, In, Zn, Mg, Mn, Sb, Pb and B
The method for producing a sliding contact material according to claim 3, wherein the content of at least one selected from i is 0.1 to 2% by weight.