JP2001173681A - Iron-base sintered alloy-made synchronizer ring excellent in seizure resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an iron-base sintered alloy-made synchronizer ring excellent in strength and wear resistance and, particularly, excellent in seizure resistance. SOLUTION: This synchronizer ring is formed of an iron-base sintered alloy having a composition containing Cu: 3-20 wt.%, Mo: 0.3-10 wt.%, and C: 0.3-2.0 wt.% and containing, as occasion demands, Zn: 0.04-0.6 wt.%, Al: 0.002-0.02 wt.%, Si: 0.02-0.2 wt.%; and the remainder consisting of inevitable impurities, and having a metallographic structure in which Mo-Fe-C compound phase mainly composed of Mo and Fe is uniformly dispersed in a base consisting of Fe-base alloy phase and Cu-base alloy phase.

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-base sintered gold having excellent strength and abrasion resistance, and particularly having excellent seizure resistance.

[0002]

2. Description of the Related Art Generally, a synchronizer ring is used by being incorporated in an automatic transmission or the like. When the synchronizer ring is moved in the + P direction so that the tapered surface 4 of the rotating tapered cone 2 contacts the inner peripheral surface 3 of the synchronizer ring 1 as shown in FIG. Is transmitted to the synchronizer ring 1, while the synchronizer ring 1 is moved in the −P direction and the tapered cone 2 is moved.
When the taper cone 2 is separated, the rotation of the tapered cone 2 is not transmitted to the synchronizer ring 1. Therefore, the synchronizer ring 1 is required to have strength enough to withstand a strong insertion pressure while being excellent in abrasion resistance, and to be compatible with the tapered cone 2 as a mating member. Is required.

Conventionally, synchronizer rings have been made of a copper-based alloy such as brass. In recent years, however, the production method of iron-based sintered alloy has advanced, and various mechanical parts made of iron-based sintered alloy have been developed. Has been able to be mass-produced with high precision, and synchronizer rings can also be manufactured from iron-based sintered alloys. As an example of a synchronizer ring made of an iron-based sintered gold, a mixed powder composed of Fe powder, Cu powder and graphite powder is press-molded and sintered to obtain Cu: 8.0 to 8.0.
15.0% by weight, C: 1.2 to 2.0% by weight,
There is known a synchronizer ring composed of an iron-based sintered alloy having a balance of Fe and unavoidable impurities and having a free Cu phase precipitated in a base material. It is also known to apply steam treatment, or steam treatment and shot blast treatment to the iron-based sintered gold synchronizer ring (see JP-A-8-177879).

[0004]

However, in the field of automatic transmissions, there is a demand for higher performance, and accordingly, the load on the synchronizer ring is further increased, and the load on the synchronizer ring is increased. There is a need for a synchronizer ring that can be obtained. For example, when accelerating an automobile equipped with an automatic transmission from a low speed to a high speed, the synchronizer ring 1 shown in FIG. 2 is moved in the + P direction, and the tapered surface 4 of the rotating taper cone 2 is moved to the inner periphery of the synchronizer ring 1. In order to further increase the acceleration at this time, it is necessary to bring the tapered surface 4 of the rotating tapered cone 2 into contact with the inner peripheral surface 3 of the synchronizer ring 1 with a higher pressure. Therefore, the load on the synchronizer ring is increasing, and a synchronizer ring having higher strength and wear resistance is required. To meet such demands, the conventional iron-based sintered gold synchronizer ring has no problem in strength and abrasion resistance, but when the load on the synchronizer ring is further increased (that is, the taper for the synchronizer ring is reduced). If the insertion pressure of the cone is further increased), the conventional iron-based sintered gold synchronizer ring has a problem that seizure occurs with the tapered cone, and if seizure occurs, the function as the synchronizer ring cannot be performed. There was a point.

[0005]

Means for Solving the Problems Accordingly, the present inventors have:
In view of the above, research has been conducted to obtain a synchronizer ring made of an iron-base sintered gold having excellent strength and wear resistance and particularly excellent seizure resistance.
u: 3 to 20% by weight, Mo: 0.3 to 10% by weight, C:
0.3 to 2.0% by weight, with the balance being Fe and unavoidable impurities, iron-based sintered gold, Cu: 3 to 20
% By weight, Mo: 0.3 to 10% by weight, C: 0.3 to 2.
0-% by weight, Zn: 0.04-0.6% by weight, the balance being iron-based sintered gold having a composition consisting of Fe and inevitable impurities, or Cu: 3-20% by weight, Mo: 0.3- 1
0% by weight, C: 0.3 to 2.0% by weight, Zn: 0.04
-0.6% by weight, and further, Si: 0.02-
0.2% by weight and / or Al: 0.002 to 0.0
2% by weight, with the balance being Fe-based sintering bonded gold composed of Fe and unavoidable impurities, wherein the structure of the iron-based sintering bonded gold is Mo and A synchronizer ring made of an iron-based sintered bond in which an Fe-based Mo-Fe-C-based compound phase is uniformly dispersed is excellent in strength and wear resistance, and also excellent in seizure resistance. It has been found that the synchronizer ring does not cause seizure even under a high load.

The present invention has been made on the basis of the above findings. (1) Cu: 3 to 20% by weight, M
o: contains 0.3 to 10% by weight, C: 0.3 to 2.0% by weight, the balance has a composition consisting of Fe and unavoidable impurities, and consists of an Fe-based alloy phase and a Cu-based alloy phase A synchronizer ring made of an iron-based sintered gold having excellent baking resistance, which is made of an iron-based sintered alloy having a structure in which Mo and Fe-based Mo-Fe-C-based compound phases are uniformly dispersed in a base material; (2) Cu: 3 to 20% by weight, Mo:
0.3 to 10% by weight, C: 0.3 to 2.0% by weight, Z
n: containing 0.04 to 0.6% by weight, the balance being composed of Fe and unavoidable impurities, and containing Mo and Fe-based Mo- in a base composed of an Fe-based alloy phase and a Cu-based alloy phase. (3) C: a synchronizer ring made of an iron-based sintered metal having excellent structure, which is composed of an iron-based sintered alloy having a structure in which Fe-C-based compound phases are uniformly dispersed.
u: 3 to 20% by weight, Mo: 0.3 to 10% by weight, C:
0.3 to 2.0% by weight, Zn: 0.04 to 0.6% by weight, Al: 0.002 to 0.02% by weight, with the balance being Fe and unavoidable impurities, And F
The baking resistance made of an iron-based sintered alloy having a structure in which a Mo-Fe-C-based compound phase mainly composed of Mo and Fe is uniformly dispersed in a matrix composed of an e-based alloy phase and a Cu-based alloy phase Excellent iron-based sintered gold synchronizer ring, (4) Cu: 3 to 20% by weight, Mo: 0.3 to 10
Wt%, C: 0.3 to 2.0 wt%, Zn: 0.04 to
0.6% by weight, Si: 0.02 to 0.2% by weight, with the balance having a composition comprising Fe and unavoidable impurities, and Mo in a base comprising an Fe-based alloy phase and a Cu-based alloy phase. And a synchronizer ring made of an iron-based sintered bond made of an iron-based sintered alloy having a structure in which a Mo-Fe-C-based compound phase mainly composed of Fe is uniformly dispersed, and having excellent baking resistance, (5) Cu : 3 to 20% by weight, Mo: 0.
3 to 10% by weight, C: 0.3 to 2.0% 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, the balance being composed of Fe and unavoidable impurities, and
The baking resistance made of an iron-based sintered alloy having a structure in which a Mo-Fe-C-based compound phase mainly composed of Mo and Fe is uniformly dispersed in a matrix composed of an e-based alloy phase and a Cu-based alloy phase It is characterized by an excellent iron-based sintered gold synchronizer ring.

The Fe-based alloy phase of the iron-based sintered bond constituting the synchronizer ring made of the iron-based sintered bond having excellent seizure resistance according to the present invention described in the above (1) to (5) is mainly composed of pearlite, and is composed of Mo. More preferably, the periphery of the -Fe-C-based compound phase has a martensitic transformation structure. Therefore, the present invention provides (6) Cu: 3 to 20% by weight, Mo: 0.3 to 10% by weight, and C: 0.3 to 2.0%.
Mo and a Mo-Fe-C-based compound phase mainly composed of Fe and Fe-based alloy phase and Cu-based alloy phase. The Fe-based alloy phase is mainly composed of pearlite, and the periphery of the Mo-Fe-C-based compound phase is made of an iron-based sintered alloy having a structure of martensitic transformation. Excellent iron-based sintered gold synchronizer ring, (7) Cu: 3 to 20% by weight, Mo: 0.3 to 10% by weight, C: 0.3 to 2.0% by weight, Zn: 0.04 to 0.6% by weight, the balance being Fe and unavoidable impurities, and Fe
A Mo-Fe-C-based compound phase mainly composed of Mo and Fe is uniformly dispersed in a matrix composed of a base alloy phase and a Cu-based alloy phase, and the Fe-based alloy phase is mainly composed of pearlite.
An o-Fe-C-based compound phase is made of an iron-based sintered alloy having a structure of martensitic transformation, and a synchronizer ring made of an iron-based sintered gold having excellent seizure resistance, (8) Cu: 3 to 20% by weight, Mo: 0.3 to 10
Wt%, C: 0.3 to 2.0 wt%, Zn: 0.04 to
0.6% by weight, Al: 0.002 to 0.02% by weight, the balance having a composition consisting of Fe and unavoidable impurities, and Mo in a matrix consisting of an Fe-based alloy phase and a Cu-based alloy phase. And the Fe-based Mo-Fe-C-based compound phase is uniformly dispersed. The Fe-based alloy phase is mainly composed of pearlite, and the structure around the Mo-Fe-C-based compound phase is martensite transformed. A synchronizer ring made of an iron-based sintered metal having excellent seizure resistance and made of an iron-based sintered alloy having the following properties: (9) Cu: 3 to 20% by weight, Mo:
0.3 to 10% by weight, C: 0.3 to 2.0% by weight, Z
n: 0.04 to 0.6% by weight, Si: 0.02 to 0.2
Mo and a Mo-Fe-C-based compound phase mainly composed of Fe and Fe-based alloy phase and Cu-based alloy phase. The Fe-based alloy phase is mainly composed of pearlite, and the periphery of the Mo-Fe-C-based compound phase is made of an iron-based sintered alloy having a structure of martensitic transformation. Excellent iron-based sintered gold synchronizer ring, (10) Cu: 3 to 20% by weight, Mo: 0.3 to 10% by weight, C: 0.3 to 2.0% by weight, Zn: 0.04 to 0.6% by weight, Al: 0.00
2 to 0.02% 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 Mo and Fe-based Mo-Fe-C-based compound phases are uniformly dispersed, and the Fe-based alloy phase is mainly composed of pearlite, and the periphery of the Mo-Fe-C-based compound phase is transformed into martensite. The present invention is characterized by an iron-based sintered gold-made synchronizer ring made of an iron-based sintered alloy having a structure and having excellent seizure resistance.

[0008] The iron-based sintered gold synchronizer ring of the present invention according to the above (1) to (10) obtained by sintering is subjected to steam treatment or shot blast treatment, and then to steam treatment. Is preferably applied. Therefore, the present invention provides (11) a baking resistance obtained by subjecting a synchronizer ring made of an iron-based sintered gold having excellent baking resistance according to any one of the above (1) to (10) to a steam treatment. An excellent synchronizer ring made of an iron-base sintered gold, (12) a shot blast treatment and a steam applied to the synchronizer ring made of an iron-base sintered gold having excellent seizure resistance according to any one of the above (1) to (10). It is characterized by a synchronizer ring made of an iron-based sintered gold having excellent anti-seizure properties, which has been subjected to a treatment.

The iron-based sintered gold synchronizer ring of the present invention, which is excellent in seizure resistance, comprises Fe powder as a raw material powder.
Powder, Cu powder, Mo-Fe compound powder (Fe: 30 to
70% by weight, the balance: a compound powder composed of Mo) and graphite powder, and further, Cu-Zn powder, Cu-Al powder, Si powder, and Cu-Zn-Al powder are prepared, and a predetermined amount of these raw material powders is blended. Then, the mixture was mixed with zinc stearate powder or ethylene bisstearamide as a lubricant by a double cone mixer and press-molded to produce a green compact. The green compact was heated in a hydrogen-containing nitrogen atmosphere at a temperature of 1100. It is manufactured by sintering at １1300 ° C. The sintering temperature at this time is more preferably 1110 to 1260 ° C.

The synchronizer ring made of iron-based sintered gold obtained in this manner is characterized in that, during sintering, C of graphite powder and Cu of Cu or Cu alloy powder are changed to Fe powder and M
Mo diffuses and infiltrates the o-Fe compound powder, Mo of the Mo-Fe compound powder diffuses and penetrates the Fe powder, and Fe diffuses and penetrates the Cu powder. After sintering, the Fe-based alloy phase and the Cu
Mo- and Fe-based Mo-
A structure in which the Fe—C-based compound phase is uniformly dispersed is obtained. The F
The e-base alloy phase is mainly made of pearlite, but Mo-F
The periphery of the e-C-based compound phase undergoes particularly remarkable martensitic transformation. The Mo-Fe-C-based compound phase mainly composed of Mo and Fe contains Fe: 3 compounded as a raw material powder during sintering.
0-70% by weight, balance: Mo-Fe having a composition of Mo
This is a compound phase formed by diffusing and infiltrating C into the compound powder, and contains some Cu by diffusing and infiltrating.
Is at most 10% by weight, and Cu is at most 5% by weight.
% By weight. Therefore, the Fe-based alloy phase and C in the iron-based sintered gold synchronizer ring of the present invention are
The “Mo-Fe-C-based compound phase mainly composed of Mo and Fe” uniformly dispersed in a base made of a u-based alloy phase is composed of Fe:
It is a compound phase containing 30 to 70% by weight, C: 10% by weight or less, Cu: 5% by weight or less, and the balance: Mo and inevitable impurities. When Al and / or Si is added as an additional element, these elements may be included as inevitable impurities in the Mo-Fe-C-based compound phase by diffusion.

Next, the reason why the component composition of the iron-based sintered alloy constituting the synchronizer ring made of an iron-based sintered gold having excellent seizure resistance according to the present invention is limited as described above will be described. (A) Cu Cu forms a free Cu alloy base structure and has an effect of improving abrasion resistance. However, if its content is less than 3% by weight, the effect is not sufficient, and on the other hand, it exceeds 20% by weight. And the soft phase increases. Therefore, the content of Cu is set to 3 to 20% by weight. A more preferable range of the Cu content is 5 to 15% by weight.

(B) Mo Mo is added as a Mo—Fe compound powder, absorbs carbon during sintering, forms a structure in which the Mo—Fe—C compound phase is uniformly dispersed in the base material, and is resistant to seizure. Has the effect of improving the martensitic transformation of the Fe alloy phase and improving the strength and hardness. However, if the content is less than 0.3% by weight, the effect is not sufficient. ,
On the other hand, if Mo is contained in the entire iron-based sintered alloy in an amount exceeding 10% by weight, the toughness decreases, which is not preferable. Therefore, the content of Mo is set to 0.3 to 10% by weight. Mo
Is more preferably in the range of 1 to 5% by weight.

(C) C C has the effect of improving the strength and the abrasion resistance, but if its content is less than 0.3% by weight, the effect of improving the strength is not sufficient. If the content exceeds 0% by weight, the dimensional accuracy deteriorates, which is not preferable. Therefore, the content of C is set to 0.3 to 2.0% by weight. A more preferable range of the content of C is 0.5 to 1.5% by weight.

(D) Zn Zn is added as necessary 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, but 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 Since Si becomes Si oxide and has an effect of improving abrasion resistance, it is added as necessary.
If the amount is less than 2% by weight, the effect is not sufficient. Therefore, the content of Si is set to 0.02 to 0.2% by weight. A more preferable range of the Si content is 0.05 to 0.1.
15% by weight.

[0017]

EXAMPLES Example 1 Fe powder having an average particle size of 70 μm was used as a raw material powder.
Average particle diameter having a composition shown in Table 1: Cu powder of 30 μm, Cu-Zn-based alloy powder, Cu-Al-based alloy powder and Cu-Zn-Al-based alloy powder, average particle diameter having a composition shown in Table 1: 45 μm Mo—Fe compound powder, S
i powder and graphite powder were prepared. These raw material powders are blended so as to have a blending composition shown in Tables 1 and 2, and zinc stearate powder, which is a lubricant at the time of mold molding, is added in an amount equivalent to 0.8% by weight on an outer surface and mixed. Then, press molding was performed to produce a synchronizer ring-shaped green compact having an inner diameter of 65 mm, a thickness of 3.5 mm, and having 36 chamfers. This green compact is
_In a mixed atmosphere of 2-5% H ₂ , temperature: 1150 ° C., 20
After sintering under the condition of minute holding, it is cooled at a cooling rate of 0.5 ° C./sec to obtain a synchronizer ring made of the iron-base sintered gold of the present invention having the component composition shown in Tables 3 and 4 Inventive rings) 1 to 19, comparative iron-based sintered gold synchronizer rings (hereinafter referred to as comparative rings) 1 to 2 and conventional iron-based sintered gold synchronizer rings (hereinafter referred to as conventional rings) were produced. .

Further, a taper cone made of JIS SCM21 steel (carburized and quenched steel) is prepared, and using this taper cone, rings 1 to 19 of the present invention and comparative rings 1 to 2 are prepared.
Various tests were performed on the conventional ring under the following conditions, and the results are shown in Tables 3 and 4.

(A) Wear test Rotation number of taper cone: 1800 rpm, pressing load: 60 kg, oil type: No. 70 gear oil, oil temperature: 80 ° C., operation of taper cone: 0.5 to 0.7 seconds synchronization The amount of wear (the amount of depression) and the coefficient of kinetic friction of the inner surface of the ring were measured under the conditions of 2,000 rpm for a time, and the results are shown in Tables 3 and 4.

(B) Seizure resistance test In the wear test (a), the pressing load was increased until the taper cone was seized on the synchronizer ring, and the pressing load at the time when seizure occurred was determined to determine the seizure resistance. evaluated.

(C) Bending test Further, in order to evaluate the strength of the synchronizer ring, the raw material powder was blended so as to have the blending composition shown in Tables 1 and 2, and further, the lubricant was used during molding. The zinc stearate powder is added and mixed in an amount equivalent to 0.8% by weight on the outside, and the mixture is press-molded to obtain 30 mm × 12 mm ×
A green compact having a bending test specimen shape having a size of 6.5 mm was prepared, and the green compact was subjected to iron-based firing in a mixed atmosphere of N ₂ -5% H ₂ at a temperature of 1150 ° C. for 20 minutes. After being made of bonded gold, it is cooled at a cooling rate of 0.5 ° C./sec to thereby provide a bending test comprising an iron-based sintered alloy having the same composition as the rings 1 to 19 of the present invention, the comparative rings 1 and 2, and the conventional ring. Each specimen was prepared, and these bending test specimens were
The bending force was measured by performing a bending test at a distance between supporting points of 25 mm based on No. 25, and the results are shown in Tables 3 and 4.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

[Table 3]

[0025]

[Table 4]

From the results shown in Tables 3 and 4, 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 amount of wear and a larger dynamic friction coefficient than the conventional rings. It can be seen that the sheet has excellent seizure resistance and high bending strength, and thus has excellent strength. However, it can be seen that Comparative Rings 1 and 2 having a component composition outside the range of the present invention are inferior in at least one of the wear amount, the dynamic friction coefficient, the seizure resistance, and the bending strength.

Further, a bending test specimen having the same composition as that of the ring 1 of the present invention was polished, and the polished surface was observed with a metallographic microscope. In FIG. 1, 5 is pearlite, 6 is martensite, 7 is a Mo—Fe—C compound phase, and 8 is a Cu-based alloy phase. As is clear from FIG. 1, the iron-based sintered metal constituting the ring 1 of the present invention contains Mo in a base material comprising an Fe-based alloy phase composed of pearlite 5 and martensite 6 and a free Cu-based alloy phase 8. And Fe-based Mo-Fe-C compound phase 7
Have a structure in which Mo-F is uniformly dispersed.
It has been found that the periphery of the eC-based compound phase has a structure that is particularly remarkably martensitic transformed.

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., the rings 39 to 19 of the present invention were treated. 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 iron-based sintered gold synchronizer ring of the present invention having excellent seizure resistance has a small amount of wear, a large coefficient of kinetic friction, a high bending strength,
Furthermore, seizure resistance is much better than conventional rings,
It can greatly contribute to the development of the automobile industry.

[Brief description of the drawings]

FIG. 1 is a sketch of a microstructure of an iron-base sintered gold constituting a synchronizer ring made of an iron-base sintered gold having excellent seizure resistance according to the present invention.

FIG. 2 is a schematic sectional view for explaining a synchronizer ring.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Synchronizer ring 2 Taper cone 3 Inner peripheral surface 4 Tapered surface 5 Perlite 6 Martensite 7 Mo-Fe-C type compound phase 8 Cu-based alloy phase

Claims (8)

[Claims] 1. Cu: 3-20% by weight, Mo: 0.3-
10% by weight, C: 0.3 to 2.0% by weight, the balance being composed of Fe and unavoidable impurities, and
It is characterized by being composed of an iron-based sintered alloy having a structure in which a Mo-Fe-C-based compound phase mainly composed of Mo and Fe is uniformly dispersed in a matrix composed of an e-based alloy phase and a Cu-based alloy phase. Synchronizer ring made of iron-base sintered gold with excellent seizure resistance. 2. Cu: 3-20% by weight, Mo: 0.3-
10% by weight, C: 0.3 to 2.0% by weight, Zn: 0.0
4 to 0.6% by weight, the balance being composed of Fe and unavoidable impurities, and Fe-based alloy phase and Cu
Mo- and Fe-based Mo-
A synchronizer ring made of an iron-based sintered gold having excellent seizure resistance, which is made of an iron-based sintered alloy having a structure in which an Fe-C-based compound phase is uniformly dispersed. 3. Cu: 3 to 20% by weight, Mo: 0.3 to 3%
10% by weight, C: 0.3 to 2.0% by weight, Zn: 0.0
4 to 0.6% by weight, Al: 0.002 to 0.02% by weight
And the remainder has a composition consisting of Fe and unavoidable impurities, and Mo and Fe-based Mo-Fe-C-based compound phase are uniformly dispersed in a base material composed of an Fe-based alloy phase and a Cu-based alloy phase. A synchronizer ring made of an iron-based sintered bond having excellent seizure resistance, which is made of an iron-based sintered alloy having a microstructure. 4. Cu: 3-20% by weight, Mo: 0.3-
10% by weight, C: 0.3 to 2.0% by weight, 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 Characterized in that it is made of an iron-based sintered alloy having a structure in which Mo and Fe-based Mo-Fe-C-based compound phases are uniformly dispersed. Nizer ring. 5. Cu: 3-20% by weight, Mo: 0.3-
10% by weight, C: 0.3 to 2.0% by weight, Zn: 0.0
4 to 0.6% by weight, Al: 0.002 to 0.02% by weight, Si: 0.02 to 0.2% by weight, the balance being F
Fe having a composition of e and unavoidable impurities, and having a structure in which Mo and Fe-based Mo-Fe-C-based compound phases are uniformly dispersed in a base material composed of an Fe-based alloy phase and a Cu-based alloy phase. Synchronizer ring made of iron-base sintered gold with excellent seizure resistance characterized by being composed of a base sintered alloy. 6. The Fe-based alloy phase is mainly composed of pearlite, and the structure around the Mo—Fe—C-based compound phase has a martensitic transformation. 4. A synchronizer ring made of an iron-based sintered gold having excellent seizure resistance according to 4 or 5. 7. An anti-seizing property, characterized in that the synchronizer ring made of an iron-base sintered gold having excellent anti-seizing property according to claim 1, 2, 3, 4, 5, or 6 is subjected to a steam treatment. Synchronizer ring made of excellent iron-base bonded gold. 8. A synchronizer ring made of an iron-based sintered metal having excellent seizure resistance according to claim 1, 2, 3, 4, 5 or 6, which is subjected to shot blasting and steaming. Synchronizer ring made of iron-base sintered gold with excellent baking resistance.