JPH03229804A - Manufacture of sliding member - Google Patents

Abstract

PURPOSE:To restrain vaporizing rate of Pb by lowering sintering temp. and to obtain a sliding member providing lining layer having excellent burning resistance and fatigue resistance by using the specific mixed powder in the manufacturing method for forming the lining layer by sintering Cu-Sn-Pb series alloy powder. CONSTITUTION:At the time of forming the lining layer by sintering the raw material powder composed of Cu-Sn-Pb series alloy, as the raw material powder, the mixed powder added with the second powder having >=7 and <13.5 of Sn component value to the first powder having <7 (Sn/(Sn+Cu)X100) of the Sn component value, is used. For example, the raw material added with the powder having composition in wt.% 8% Sn, 15% Pb, 77% Cu and 9.4% Sn component value at 50wt.% as the second powder to the powder having composition of 4% Sn, 23% Pb, 73% Cu and 5.2% the Sn component value as the first powder, is used. This raw material powder has composition of 6% Sn, 19% Pb, 75% Cu and 7.4% the Sn component value.

Description

Detailed Description of the Invention A9 Object of the Invention (1) Industrial Application Field The present invention relates to a method for manufacturing a sliding member, and in particular, to a method for manufacturing a sliding member, in particular, a Cu-3n-Pb based alloy is The present invention relates to an improvement in a method of forming a lining layer by sintering a raw material powder consisting of:

(2) Conventional technology Conventionally, Cu-3n-Pb alloys contain about 20% by weight of PB, for example, from the viewpoint of improving seizure resistance, and have an Sn content value (S n /S n + Cu)X10.
Lead bronze with 0 set to less than 7 is used.

In this type of alloy, Pb does not form a solid solution in the Cu-3n matrix, so the sintering takes place mainly between CU and Sn, and the sintering temperature is therefore dominated by the diffusion temperature of the Cu-3n matrix.

Conventionally, the sintering temperature was set at 800°C depending on the Sn component value.
It is set above.

(3) Problems to be solved by the invention However, if the sintering temperature is set high as described above,
Due to non-solid solution of Pb, Pb
As the Pb content begins to evaporate rapidly, the Pb content may fall below the set value, adversely affecting the seizure resistance of the lining layer.
Further, Pb aggregates densely at the grain boundaries of the Cu-3n matrix, resulting in a problem that the fatigue resistance of the lining layer is impaired.

In view of the above, the present invention uses a specific mixed powder as a raw material powder to lower the sintering temperature and significantly suppress the amount of Pb evaporation, thereby providing a lining layer with excellent seizure resistance and fatigue resistance. It is an object of the present invention to provide the above-mentioned manufacturing method, which makes it possible to obtain a sliding member having the following features.

B0 Structure of the Invention (1) Means for Solving the Problems The present invention provides Cu-3n on the sliding surface side of the back metal with the mating member.
- In a method for manufacturing a sliding member in which a lining layer is formed by sintering a raw material powder made of a Pb-based alloy, the raw material powder is a first powder having an Sn component value (Sn/Sn+Cu)Xl 00 of less than 7; Sn component value (Sn/Sn+Cu)
It is characterized by using a mixed powder to which a second powder having an X100 of 7 or more and less than 13.5 is added.

(2) Effect When the raw material powder is used, the sintering temperature can be set to 780° C. or lower, thereby making it possible to significantly suppress the amount of PB evaporated.

(3) Example 1. In the second flash, the plane bearing l as a sliding member is attached to a journal portion of a crankshaft in an engine.
It is applied to the large end of a connecting rod, etc., and consists of the first and second halves 1+ and '1g. Both halves l3, 1□ have the same structure, and include a back metal 2, a lining layer 3 formed by a powder sintering method on the sliding surface side of the back metal 2 with the mating member, and a surface of the lining layer 3. and a surface layer 4 formed by electroplating. A copper plating layer is provided between the backing layer 2 and the lining layer 3, and a nickel mesoki barrier layer is provided between the lining layer 3 and the surface layer 4, as required.

The back metal 2 is made of a rolled steel plate, and its thickness is equal to that of the plane bearing 1.
Determined by the set thickness. Lining layer 3 is Cu-
Composed of 3n-Pb alloy, its thickness is 50~50
0 μm1 is usually about 300 μm. The surface layer 4 is made of, for example, a Pb alloy, and has a thickness of 5 to 50 μm.
Usually it is about 20 μm. This surface layer 4 is intended to improve the initial conformability with the mating member, and will wear out as the sliding time progresses.

The lining layer 3 has a composition of 16% by weight or more and less than 24% by weight of Pb, 4% by weight or more and less than 10% by weight of Sn, and the balance Cu.

When the Pb content is less than 16% by weight, seizure resistance is low, while when it is 24% by weight or more, fatigue resistance is reduced. When the content of Sn is less than 4% by weight, fatigue resistance is low, whereas the effect remains unchanged even when it is added in an amount of 10% by weight or more.

Figure 3 shows P in Cu-7wt%Sn--Pb alloy.
The relationship between the b content and the surface pressure at which seizure occurs is shown.

The seizure resistance test was conducted using a chip-on-disc tester, and the test conditions were as follows. disk J
IS 548C material subjected to liquid nitriding treatment, oil temperature 100°C, oil supply speed 150 c c/s
in, maximum load 300kg/d, disc rotation speed 1
8 m/s (constant).

From FIG. 3, it can be seen that when the Pb content is less than 16% by weight, the surface pressure at which seizure occurs is drastically reduced.

The lining layer 3 is formed by a conventional method and a method for forming the lining layer.
Correction of secondary surface degree, scattering of raw material powder onto rolled steel strip, primary sintering, primary rolling, correction of secondary surface degree, secondary sintering, secondary rolling,
Each winding process is performed sequentially. In this case, the secondary sintering temperature is set to be 20 to 30'C lower than the primary sintering temperature, and therefore, the growth of PB poses a problem in the primary sintering process.

As the raw material powder, the Sn component value (S n /S n
+Cu)X100 is less than 7, the Sn component value (
A mixed powder to which a second powder having Sn/Sn+Cu)xl oo of 7 or more and less than 13°5 is added is used.

The fourth loop shows the relationship between the primary sintering temperature and the PB reduction rate in a Cu-7wt%Sn--19wt%PB alloy, and the sintering time was set to 30 minutes.

It can be seen from FIG. 4 that the amount of Pb evaporated increases rapidly when the primary sintering temperature is around 800°C.

Figure 5 shows the main part of the binary equilibrium phase diagram of the Cu-3n alloy, where the line X is the solidus line from the melting point of 1083°C, and the solidus temperature increases as the Sn content increases. This trend continues until the Sn component value reaches 13.5. The solidus temperature at this Sn component value of 13.5 is 79 B''
C, and this temperature is constant from Sn component value 13.5 to 25.

The line y shows the diffusion temperature of the Cu7Sn matrix, which is about 100° C. lower than the solidus temperature for Sn content values below 13.5.

4th. Considering the line y in Figure 5, in order to significantly suppress the amount of PB evaporation, the primary sintering temperature should be set lower than 800°C, that is, 780°C or lower with safety in mind. Therefore, the Sn component value of the raw material powder is 7.
Must be above.

Figure 6 shows the results of the first sintering process when the primary sintering temperature is changed.
The relationship between the amount of the second powder added to the powder and the average defect rate of the lining layer is shown.

The compositions of the first and second powders are as shown in Table I.

Table I Average defect rate is expressed as the area ratio of the unfilled portion to the surface area of the lining layer.

In Figure 6, line 2. ~2. is the primary sintering temperature of 750.77
This applies when the temperature is set to 0,800°C.

As is clear from Fig. 6, when the primary sintering temperature is set at a relatively high temperature of 770°C, in order to reduce the average defect rate of the lining layer to 1% or less, it is necessary to
It is necessary to add powder in an amount of 50% by weight or more.

The Cu-3n-Pb alloy constituting the raw material powder contains Ni, Ti, Si, Zn, and Mn as necessary.

Fe, Zr, S, Sb and A1. At least one selected from the following is added.

The primary and secondary rolling steps are performed using rollers, and the rolling reduction ratio is 50 to 70% in the primary rolling process and 5 to 70% in the secondary rolling process.
Each is set to 20%.

〔Example〕

By applying the atomization method, various raw material powders having the compositions shown in Table 1 and having a diameter of 150 μm or less were manufactured.

Table 1 In Table H, raw material powder a is the powder used in the present invention. This raw material powder a uses raw material powder e as a first powder,
To this, 50% by weight of raw material powder was added as a second powder, and the composition was the same as raw material powder C. Note that the raw material powders e and b are the same as No. 1 in Table I. corresponding to the second powder, respectively.

For experiments, various planar bearings were manufactured using each of the raw material powders a to e through the following operations.

(2) Lining layer forming operation (i) Raw material powder was spread to a thickness of 1 m onto a 1.6 m thick rolled steel plate for a backing metal.

(ii) The raw material powder was subjected to primary sintering treatment in a reducing atmosphere. In this case, the primary sintering temperature is the raw material powder a −
d was set at 770°C, and raw material powder e was set at 820°C.

(■) Reduction rate of approximately 65% for rolled steel plate and primary sintered layer
A primary rolling treatment was performed.

(1■) The rolled steel plate and the primary sintered layer were subjected to flatness correction treatment using a roller.

(■) The primary sintered layer was subjected to secondary sintering treatment. In this case, the secondary sintering temperature is 20° higher than the primary sintering temperature.
°C was set low.

(vi) Rolled steel plate and secondary sintered layer have a reduction rate of approximately 1
A bearing material having a lining layer 3 made of a secondary sintered layer with a thickness of 300 μm was obtained by performing a 4% secondary rolling treatment.

■0 Machining work The bearing material is subjected to press working, various cutting processes, etc.
A pair of intermediates corresponding to 1 g of the second half was obtained.

■Electroplating process Each intermediate is electroplated using PB gold alloy,
A surface layer 4 having a thickness of 20 μm was formed on the lining layer 3.

Table 3 shows the primary sintering temperature and physical properties of the lining layer in various flat bearings. For convenience, the same reference numerals as those of the raw material powder are used in the present invention and each comparative example.

Further, the seizure resistance test was conducted in the same manner and under the same conditions as in the example shown in FIG.

As is clear from Table (2), the primary sintering temperature of the present invention a is 50°C lower than that of the comparative example e corresponding to the conventional example, and as a result, the amount of evaporation of Pb can be significantly suppressed. As a result, the present invention a has a higher surface pressure at which seizure occurs than the comparative example e, and also has excellent fatigue resistance due to improved hardness and tensile strength. This also applies to comparative examples c and d.

Since the comparative example has a Pb content of 15% by weight, the surface pressure at which seizure occurs is low.

Note that the present invention is not limited to plane bearings, and can naturally be applied to the manufacture of other sliding members.

Effects of the C0 Invention According to the present invention, by using the mixed powder specified as described above as the raw material powder, the sintering temperature of the raw material powder is lowered and the amount of PB evaporated is significantly suppressed. A sliding member with a lining layer having seizure resistance and fatigue resistance can be obtained.

[Brief explanation of drawings]

Figure 1 is an exploded plan view of the plain bearing, Figure 2 is Figure 1 - ■
3 is a graph showing the relationship between the Pb content and the surface pressure at which seizure occurs. FIG. 4 is a graph showing the relationship between the primary sintering temperature and the Pb reduction rate. FIG. 6, which is a partial diagram of the binary equilibrium phase diagram of the Sn-based alloy, is a graph showing the relationship between the amount of the second powder added and the average defect rate. 1... Plane bearing (sliding member), 2... Back metal, 3...
・Lining layer

Claims (2)

[Claims] (1) Cu-Sn-P on the sliding surface side of the back metal with the mating member.
In the method for manufacturing a sliding member in which a lining layer is formed by sintering a raw material powder made of a b-based alloy, the raw material powder is a first powder whose Sn component value (Sn/Sn+Cu)×100 is less than 7; Component value (Sn/Sn+Cu) x 10
A method for manufacturing a sliding member, characterized in that a mixed powder containing a second powder having a zero value of 7 or more and less than 13.5 is used. (2) the amount of the second powder added is 50% by weight or more;
The method for manufacturing a sliding member according to item (1).