JPH11302804A - Synchronizer ring made of iron-base sintered alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synchronizer ring made of iron-base sintered alloy, excellent in strength and wear resistance. SOLUTION: This synchronizer ring is constituted of an iron-base sintered alloy which has a composition consisting of, by weight, 8-20% Cu, 0.06-1.2% Mn, 1.0-2.0% C, and the balance Fe with inevitable impurities and containing, if necessary, 0.04-0.6% Zn, 0.002-0.02% Al, and 0.02-0.2% Si and also has a structure where free graphite phases and further, if necessary, silicon oxide phases are uniformly dispersed in a matrix consisting of Fe-base alloy phases and Cu-base alloy phases.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronizer ring made of an iron-based sintered alloy having excellent strength and wear resistance.

[0002]

2. Description of the Related Art In recent years, manufacturing methods of iron-based sintered alloys have advanced, and various types of mechanical parts made of iron-based sintered alloys can be produced in large quantities with high precision. Synchronizer rings are also made of iron-based sintered alloys. Manufacturing has begun. As an example of a synchronizer ring made of an iron-based sintered alloy, a mixed powder composed of an Fe powder, a Cu powder and a graphite powder is press-molded, sintered, and Cu: 8.0 to 15.0% by weight, C:
2. Description of the Related Art A synchronizer ring comprising an iron-based sintered alloy containing 1.2 to 2.0% by weight, the balance being Fe and unavoidable impurities, and having a free Cu phase precipitated in a base material is known. I have. It is also known that a synchronizer ring made of an iron-based sintered alloy obtained by sintering is subjected to a steam treatment or a steam treatment and a shot blast treatment (see JP-A-8-177879).

[0003]

However, the conventional synchronizer ring made of an iron-based sintered alloy has a problem that Cu
Penetrates into the Fe powder boundary and lowers the bonding strength between Fe powders, so that it does not have sufficient strength, and therefore cannot respond to recent high performance, high load and light weight, There has been a demand for a synchronizer ring made of an iron-based sintered alloy having even higher strength and wear resistance.

[0004]

Means for Solving the Problems Accordingly, the present inventors have:
From the above viewpoints, research was conducted to obtain a synchronizer ring made of an iron-based sintered alloy having higher strength and wear resistance than before, and (a) Cu alloy powder containing Fe and Mn was Cu obtained by mixing, molding and sintering Fe powder and graphite powder: 8 to 2
0% by weight, Mn: 0.06 to 1.2% by weight, C: 1.0
The synchronizer ring made of an iron-based sintered alloy having a composition of about 2.0% by weight and the balance consisting of Fe and unavoidable impurities has a low Cu penetration into the Fe powder boundary during sintering. (B) mixing Fe powder and graphite powder with Cu alloy powder containing Fe and Mn and further containing Zn, which does not lower the bonding strength between the powders,
Formed and sintered, Cu: 8 to 20% by weight, Mn: 0.06 to 1.2% by weight, C: 1.0 to
2.0% by weight, and Zn: 0.04 to 0.6
The synchronizer ring made of an iron-based sintered alloy having a composition containing iron and an unavoidable impurity in the content of Fe is less likely to penetrate into the boundaries of Fe powder during sintering. (C) containing Fe and Mn and further containing Zn and Al without lowering the strength
Cu powder obtained by mixing Fe powder and graphite powder with a Cu alloy powder containing
0% by weight, Mn: 0.06 to 1.2% by weight, C: 1.0
２．０2.0% by weight, and Zn: 0.04４0.4%.
A synchronizer ring made of an iron-based sintered alloy having a composition of 6% by weight, Al: 0.002 to 0.02% by weight, and the balance consisting of Fe and unavoidable impurities, has Cu at the boundary of Fe powder during sintering. (D) the iron-based sintered alloy of (a), (b) or (c) obtained in this way, which has low penetration and therefore does not lower the bonding strength between Fe powders. The synchronizer ring has a structure in which a free graphite phase is uniformly dispersed in a body composed of an Fe-based alloy phase and a Cu-based alloy phase. (E) The synchronizer ring made of the iron-based sintered alloy is an Fe-based alloy. It is more preferable to have a structure in which a free graphite phase and silicon oxide or surface-oxidized silicon are uniformly dispersed in a matrix composed of a base phase and a Cu-based alloy phase.
-20% by weight, C: 1.0-2.0% by weight, Mn: 0.
06 to 1.2% by weight, Zn: 0.04 to 0.6% by weight,
Si: a composition containing 0.02 to 0.2% by weight, with the balance being Fe and unavoidable impurities, or Cu: 8 to 20
% By weight, C: 1.0 to 2.0% by weight, Mn: 0.06 to
1.2% by weight, Zn: 0.04 to 0.6% by weight, Al:
0.002 to 0.02% by weight, Si: 0.02 to 0.2
It has been found that it is more preferable that the composition contains a weight% and the remainder has a composition composed of Fe and inevitable impurities.

The present invention has been made on the basis of such findings, and (1) Cu: 8 to 20% by weight, C:
1.0 to 2.0% by weight, Mn: 0.06 to 1.2% by weight
And an iron-based sintered alloy having a composition in which the balance consists of Fe and unavoidable impurities, and has a structure in which a free graphite phase is uniformly dispersed in a base material composed of an Fe-based alloy phase and a Cu-based alloy phase. Synchronizer ring made of the iron-based sintered alloy, (2) Cu: 8 to 20% by weight, C: 1.
0 to 2.0% by weight, Mn: 0.06 to 1.2% by weight, Z
n: 0.04 to 0.6% by weight, the balance having a composition of Fe and unavoidable impurities, and free graphite phase uniformly dispersed in a base material of an Fe-based alloy phase and a Cu-based alloy phase Synchronizer ring made of an iron-based sintered alloy composed of an iron-based sintered alloy having the following structure, (3) C
u: 8 to 20% by weight, C: 1.0 to 2.0% by weight, M
n: 0.06 to 1.2% by weight, Zn: 0.04 to 0.6
%, Al: 0.002 to 0.02% by weight,
The remainder is composed of an iron-based sintered alloy having a composition of Fe and unavoidable impurities and having a structure in which a free graphite phase is uniformly dispersed in a base material of an Fe-based alloy phase and a Cu-based alloy phase. Synchronizer ring made of iron-based sintered alloy, (4) Cu: 8 to 20% by weight, C: 1.0 to 2.0
Wt%, Mn: 0.06 to 1.2 wt%, Zn: 0.0
4 to 0.6% by weight, Si: 0.02 to 0.2% by weight, the balance having a composition comprising Fe and unavoidable impurities, and a base material comprising an Fe-based alloy phase and a Cu-based alloy phase A synchronizer ring made of an iron-based sintered alloy made of an iron-based sintered alloy having a structure in which a free graphite phase and a silicon phase whose surface is oxidized are uniformly dispersed, (5) C
u: 8 to 20% by weight, C: 1.0 to 2.0% by weight, M
n: 0.06 to 1.2% by weight, Zn: 0.04 to 0.6
% By weight, Al: 0.002 to 0.02% by weight, Si:
Silicon having a composition of 0.02 to 0.2% by weight, the balance being Fe and unavoidable impurities, and a free graphite phase and a surface oxidized in a base composed of an Fe-based alloy phase and a Cu-based alloy phase Synchronizer ring made of an iron-based sintered alloy composed of an iron-based sintered alloy having a structure in which phases are uniformly dispersed, (6) Cu: 8 to 20% by weight, C:
1.0-2.0 wt%, Mn: 0.06-1.2 wt%, Zn: 0.04-0.6 wt%, Si: 0.02-
0.2% by weight, with the balance being Fe and unavoidable impurities, and free graphite phase and silicon oxide phase uniformly dispersed in a matrix composed of an Fe-based alloy phase and a Cu-based alloy phase Synchronizer ring made of iron-based sintered alloy composed of iron-based sintered alloy having a structure,
(7) Cu: 8 to 20% by weight, C: 1.0 to 2.0% by weight, Mn: 0.06 to 1.2% by weight, Zn: 0.04 to
0.6% by weight, Al: 0.002 to 0.02% by weight, S
i: free graphite phase and silicon oxide phase in a base material containing 0.02 to 0.2% by weight, the balance being Fe and inevitable impurities, and comprising a Fe-based alloy phase and a Cu-based alloy phase Is characterized by an iron-based sintered alloy synchronizer ring composed of an iron-based sintered alloy having a structure in which is dispersed uniformly.

The iron-based sintered alloy synchronizer ring of the present invention described in (1) to (7) obtained by sintering is preferably subjected to steam treatment or shot blast treatment and then to steam treatment. . Therefore, the present invention provides (8) the above (1), (2), (3), (4),
(5), (6) or (7), an iron-based sintered alloy synchronizer ring obtained by performing a steam treatment on the iron-based sintered alloy synchronizer ring;
(2), (3), (4), (5), (6) or (7)
A synchronizer ring made of an iron-based sintered alloy obtained by applying a shot blast treatment and a steam treatment to the synchronizer ring made of an iron-based sintered alloy described above.

Mn and Fe inhibit the solid solution of Cu into Fe during sintering and have the effect of suppressing the penetration of Cu into the boundaries of Fe powder. Therefore, Cu alloy powder containing Mn and Fe is used. By doing so, the solid solution of Cu into Fe is inhibited during sintering, the penetration of Cu to the boundaries of Fe powder is suppressed, and the sintering strength between the Fe powders is increased, so that an iron-based sintered bond having excellent strength is provided. A gold synchronizer ring can be obtained. In this case, since Al has the same function, Cu alloy powder containing Mn and Fe containing Al is used as necessary.

Accordingly, the synchronizer ring made of an iron-based sintered alloy according to the present invention is characterized in that, as a raw material powder, Fe: 0.6 to
A Cu alloy powder, an Fe powder, and a graphite powder containing 6.0% by weight, Mn: 0.3 to 7% by weight, and further containing Al: 0.01 to 0.2% by weight as needed are prepared. Then, prepare a silicon powder or a silica powder whose surface is oxidized, mix these raw material powders in a predetermined amount, further mix with zinc stearate powder or ethylene bis stearamide as a lubricant in a double cone mixer, press-mold. The green compact is manufactured by sintering the green compact at a temperature of 1050 to 1300 ° C. in a hydrogen atmosphere containing nitrogen. The sintering temperature at this time is more preferably 1100 to 1260 ° C.

Next, the reason why the component composition of the iron-based sintered alloy constituting the synchronizer ring made of the iron-based sintered alloy of the present invention is limited as described above will be described. (A) Cu Cu has an effect of improving abrasion resistance. However, if its content is less than 8% by weight, the effect is not sufficient, while if it exceeds 20% by weight, strength is undesirably reduced. Therefore, the content of Cu is set to 8 to 20% by weight. Cu
Is more preferably in the range of 10 to 18% by weight.

(B) C C has the effect of improving the strength and has the effect of precipitating a graphite phase which contributes to the improvement of the abrasion resistance. If the content is less than 1.0% by weight, the effect of improving the strength is obtained. Is not enough
On the other hand, when the content exceeds 2.0% by weight, the dimensional accuracy deteriorates, which is not preferable. Therefore, the content of C is 1.
It was set to 0 to 2.0% by weight. A more preferable range of the content of C is 1.1 to 1.6% by weight.

(C) Mn Mn is dissolved in Fe to improve the strength of the Cu alloy phase.
Furthermore, it has the effect of inhibiting the solid solution of Cu in Fe during sintering and suppressing the penetration of Cu into the boundaries of Fe powder. However, if the content is less than 0.06% by weight, the effect is not sufficient. On the other hand, if Mn exceeds 1.2% by weight in the entire iron-based sintered alloy, the strength is undesirably reduced. Therefore, the content of Mn is set to 0.06 to 1.2% by weight. A more preferred range of the Mn content is 0.2 to 0.9.
% By weight.

(D) Zn Zn is added as needed because it has the effect of improving the strength of the Cu alloy phase, but its content is 0.04% by weight.
If it is less than 0.5%, the effect of improving the strength of the Cu alloy phase is not sufficient. On the other hand, if it exceeds 0.6% by weight, the toughness decreases, which is not preferable. Therefore, the content of Zn is 0.0
It was determined to be 4-0.6% by weight. A more preferable range of the Zn content is 0.2 to 0.4% by weight.

(E) Al Al is added as necessary because it has the effect of improving the strength of the Cu alloy phase. If its content is less than 0.002% by weight, the effect of improving the strength of the Cu alloy phase is sufficient. On the other hand, if the content exceeds 0.02% by weight, the toughness decreases, which is not preferable. Therefore, the content of Al is 0.1.
002 to 0.02% by weight. A more preferable range of the Al content is 0.005 to 0.015% by weight.

(F) Si Si becomes Si oxide and has an effect of improving abrasion resistance. However, if its content is less than 0.02% by weight, the effect is not sufficient. Exceeding this is not preferred because the strength is reduced. Therefore, the content of Si is 0.1.
It was set to 02 to 0.2% by weight. A more preferable range of the Si content is 0.05 to 0.15% by weight.

[0015]

EXAMPLES Example 1 Fe powder having an average particle size of 55 μm was used as a raw material powder.
, Cu alloy powders A to K having the average particle diameter and the component composition shown in Table 1, graphite powder having an average particle diameter of 18 µm, average particle diameter:
10 μm surface oxidized Si powder, and average particle size:
A 10 μm silica powder was prepared.

[0016]

[Table 1]

These raw material powders are blended so as to have the composition shown in Tables 2 and 3, and zinc stearate powder, which is a lubricant at the time of mold molding, is used in an amount corresponding to 0.8% by weight on an outer surface. Add, mix and press-mold to create an inner diameter of 6
A synchronizer ring-shaped green compact having a size of 5 mm and a thickness of 3.5 mm and having 36 chamfers was prepared. After sintering this green compact in a mixed atmosphere of N ₂ -5% H ₂ at a temperature of 1150 ° C. and holding for 20 minutes, it is cooled at a cooling rate of 0.5 ° C./sec. Synchronizer rings made of the iron-based sintered alloy of the present invention (hereinafter, referred to as the present ring) 1 to 19 and synchronizer rings made of the comparative iron-based sintered alloy (hereinafter, referred to as the comparative ring) having the component compositions shown in Table 6 ) 1 to 6 were prepared. Further, a Cu powder is prepared, and the Cu powder and the graphite powder are blended so as to have a blending composition shown in Table 3, mixed, and then sintered. Nizer ring (hereinafter,
A conventional ring) was manufactured.

Further, a taper cone made of JIS SCM21 steel (carburized and quenched steel) is prepared, and the abrasion resistance of the rings 1 to 19 of the present invention, the comparative rings 1 to 6, and the conventional ring is obtained using the taper cone under the following conditions. A test was conducted to measure the amount of wear (fall) and the coefficient of kinetic friction of the inner surface of the ring, and the results are shown in Tables 4 to 6.

Test conditions Taper cone rotation speed: 1800 rpm, pressing load: 60 kg, oil type: No. 70 gear oil, oil temperature: 80 ° C., operation of taper cone: 2,000 rpm with synchronization time of 0.5 to 0.7 seconds ,

Further, in order to evaluate the strength of the synchronizer ring, the raw material powder was blended so as to have the composition shown in Tables 2 and 3, and zinc stearate powder which was a lubricant at the time of molding was used. Was added in an amount equivalent to 0.8% by weight on the outside, mixed and press-molded to obtain 30 mm ×
A bending test piece-shaped green compact having a size of 12 mm × 6.5 mm was prepared, and the green compact was heated in a mixed atmosphere of N ₂ -5% H ₂ at a temperature of 1150 ° C. for 20 minutes. After making the base sintered alloy, the rings were cooled at a cooling rate of 0.5 ° C./sec.
And a bending test piece made of an iron-based sintered alloy having the same composition as that of the conventional ring.
The bending force was measured by performing a bending test at a distance between supports of 25 mm based on SO3325, and the results are shown in Tables 4 to 6.

[0021]

[Table 2]

[0022]

[Table 3]

[0023]

[Table 4]

[0024]

[Table 5]

[0025]

[Table 6]

From the results shown in Tables 2 to 6, when the rings 1 to 19 of the present invention are compared with the conventional rings, the rings 1 to 19 of the present invention have a smaller wear amount and a larger dynamic friction coefficient than the conventional rings. Furthermore, it can be seen that the strength is excellent from the place where the bending strength is high. However, it can be seen that the comparative rings 1 to 6 having a component composition outside the scope of the present invention are inferior in at least one of the wear amount, the dynamic friction coefficient, and the bending strength.

Further, a bending test piece having the same component composition as that of the ring 1 of the present invention was polished, and the polished surface was observed with a metallographic microscope. As a result, the free graphite phase was found in a matrix composed of an Fe-based alloy phase and a Cu-based alloy phase. Has a structure in which is dispersed uniformly. Further, a bending test piece having the same composition as that of the ring 16 of the present invention is polished, and the polished surface is observed with a metallographic microscope. The free graphite phase and the surface are oxidized. It has a structure in which the silicon phase is uniformly dispersed.
A bending test piece having the same component composition as that of No. 9 was polished, and the polished surface was observed with a metallographic microscope. As a result, it was found that the structure had a structure in which the free graphite phase and the silicon oxide phase were uniformly dispersed.

Example 2 The ring 1 of the present invention was obtained by holding the rings 1 to 19 of the present invention obtained in Example 1 in steam at 500 ° C. for 60 minutes.
The rings 20 to 38 of the present invention were produced by performing a steam treatment for forming a ferric oxide film on the surfaces of Nos. 19 to 19, and the rings 20 to 38 of the present invention were subjected to an abrasion resistance test under the same conditions as in Example 1. As a result, the wear amount of the rings 20 to 38 of the present invention was 80 to 90% of that of the rings 1 to 19 of the present invention.

Example 3 After subjecting the rings 1 to 19 of the present invention obtained in Example 1 to a shot blasting treatment, and further performing a steaming treatment for 60 minutes in steam at 500 ° C. to obtain the rings of the present invention 39 to 19. 57 of this invention ring 39-5
7 was subjected to a wear resistance test under the same conditions as in Example 1, and as a result, the wear amounts of the rings 39 to 57 of the present invention were reduced to the rings 1 to 19 of the present invention.
70-80%.

[0030]

As described above, the synchronizer ring made of an iron-based sintered alloy according to the present invention has a small amount of wear, a large coefficient of kinetic friction, and a high bending strength. A synchronizer ring made of a base sintered alloy can be provided, which can greatly contribute to the development of the automobile industry.

Claims (9)

[Claims] 1. Cu: 8 to 20% by weight, C: 1.0 to
2.0% by weight, Mn: 0.06 to 1.2% by weight, the balance having a composition of Fe and unavoidable impurities, and free in a base material of an Fe-based alloy phase and a Cu-based alloy phase A synchronizer ring made of an iron-based sintered alloy, wherein the synchronizer ring is made of an iron-based sintered alloy having a structure in which a graphite phase is uniformly dispersed. 2. Cu: 8 to 20% by weight, C: 1.0 to
2.0% by weight, Mn: 0.06 to 1.2% by weight, Zn:
It contains 0.04 to 0.6% by weight, the balance has a composition consisting of Fe and inevitable impurities, and the free graphite phase is uniformly dispersed in a matrix consisting of an Fe-based alloy phase and a Cu-based alloy phase. A synchronizer ring made of an iron-based sintered alloy, which is made of an iron-based sintered alloy having a structure. 3. Cu: 8 to 20% by weight, C: 1.0 to
2.0% by weight, Mn: 0.06 to 1.2% by weight, Zn:
0.04 to 0.6% by weight, Al: 0.002 to 0.02
% By weight, the balance being Fe and unavoidable impurities, and having a structure in which a free graphite phase is uniformly dispersed in a body composed of an Fe-based alloy phase and a Cu-based alloy phase. Synchronizer ring made of iron-based sintered alloy, which is made of gold. 4. Cu: 8-20% by weight, C: 1.0-
2.0% by weight, Mn: 0.06 to 1.2% by weight, Zn:
It contains 0.04 to 0.6% by weight, Si: 0.02 to 0.2% by weight, the balance has a composition consisting of Fe and inevitable impurities, and consists of an Fe-based alloy phase and a Cu-based alloy phase. A synchronizer ring made of an iron-based sintered alloy, comprising a ferrite-based sintered alloy having a structure in which a free graphite phase and a silicon phase whose surface is oxidized are uniformly dispersed in a base material. 5. Cu: 8 to 20% by weight, C: 1.0 to
2.0% by weight, Mn: 0.06 to 1.2% by weight, Zn:
0.04 to 0.6% by weight, Al: 0.002 to 0.02
% By weight, Si: 0.02 to 0.2% by weight, with the balance being Fe and unavoidable impurities.
It is characterized by being composed of an iron-based sintered alloy having a structure in which a free graphite phase and a silicon phase whose surface is oxidized are uniformly dispersed in a matrix formed by combining an e-based alloy phase and a Cu-based alloy phase. Synchronizer ring made of iron-based sintered alloy. 6. Cu: 8 to 20% by weight, C: 1.0 to
2.0% by weight, Mn: 0.06 to 1.2% by weight, Zn:
It contains 0.04 to 0.6% by weight, Si: 0.02 to 0.2% by weight, the balance has a composition consisting of Fe and inevitable impurities, and consists of an Fe-based alloy phase and a Cu-based alloy phase. A synchronizer ring made of an iron-based sintered alloy, which is made of an iron-based sintered alloy having a structure in which a free graphite phase and a silicon oxide phase are uniformly dispersed in a base material. 7. Cu: 8-20% by weight, C: 1.0-
2.0% by weight, Mn: 0.06 to 1.2% by weight, Zn:
0.04 to 0.6% by weight, Al: 0.002 to 0.02
% By weight, Si: 0.02 to 0.2% by weight, with the balance being Fe and unavoidable impurities.
An iron-based sintered alloy comprising an iron-based sintered alloy having a structure in which a free graphite phase and a silicon oxide phase are uniformly dispersed in a matrix composed of an e-based alloy phase and a Cu-based alloy phase Synchronizer ring. 8. The method of claim 1, 2, 3, 4, 5, 6, or 7.
A synchronizer ring made of an iron-based sintered alloy, wherein the synchronizer ring made of an iron-based sintered alloy described above is subjected to a steam treatment. 9. The method of claim 1, 2, 3, 4, 5, 6, or 7.
A synchronizer ring made of an iron-based sintered alloy, wherein the synchronizer ring made of an iron-based sintered alloy described above is subjected to a shot blast treatment and a steam treatment.