JPH068444B2 - Manufacturing method of bearing material made of ferrous sintered alloy - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a bearing material made of a ferrous sintered alloy.

2. Description of the Related Art Conventional bearing materials using back metal have been copper, mainly Cu-10%, Sn-10% Pb alloys. This alloy system secured the lubrication characteristics by Pb and had the strength by the Cu-Sn alloy phase.

Problems to be Solved by the Invention The above Cu—Sn alloy phase is not suitable for high load bearings because it does not have sufficient strength under high load. Therefore, similar iron-based bearing materials are desired. However, iron-based materials have the drawback of weak bonding strength with back metal. In addition, in the iron-based materials, the sintering temperature is as high as 1000 to 1150 ° C, but the melting point of lead is low. .

Fig. 2 (A) and (B) shows the state, and Fe powder and Cu-
When a mixture of Sn alloy powder and Pb powder is sintered as shown in Fig. (A), it is sintered between Fe and Cu-Sn particles as shown in (B).
Will be segregated.

Means and Actions for Solving Problems The present invention has been conceived in view of the above, and lead is segregated in a sintered body by adding lead to iron powder in a kermet (Cu-Pb) powder. It is intended to prevent the formation of a uniform sintered body.

That is, the present invention, iron, kelmet, using a mixed powder consisting of a specific ratio of tin, by sintering at a relatively low temperature as an iron-based 800 ~ 900 ℃, rich in self-lubricating, sufficient strength, This is a method for producing a bearing material capable of joining an iron-based sintered alloy having a uniform structure to a back metal and sufficiently exhibiting a function as a bearing for high load.

And the main point is that iron (Fe) is the main component and 5-30% kelmet (3-20% Cu, 2-10%).
Pb), mixed powder containing 1-5% (Sn) is sprayed on the steel plate, then primary sintering is performed at 800-900 ° C., then this sintered body is rolled to a predetermined density, and further 800 Secondary sintering is performed at ˜900 ° C., and then secondary rolling is performed to obtain a sintered material having high bonding strength with the back metal. All percentages in the present specification are weight percentages.

The effect of the additive element of the iron-based sintered alloy and the reason for limitation are as follows.

The kelmet powder is an alloy powder of lead, and the proportion of lead in the whole is adjusted to 2 to 10% by adding 5 to 30% of this. Lead acts as a lubricant during sliding and has the effect of preventing seizure. When lead is added alone, as shown in FIG. 2, the liquid phase of lead melted at the melting point (32.75 ° C.) moves through the pores in the sintered body and tends to partially segregate. When this is added with kermet powder, the state before sintering shown in Fig. 1 (A) changes to the state after sintering shown in (B),
Tin diffuses in the kermet, and lead remains relatively in the copper and tin alloy, and a uniform sintered body is obtained.

Tin melts at its melting point (231 ° C) and diffuses into the copper in the kermet to form a Cu-Sn alloy. The Cu-Sn alloy acts as a binding material for iron powders, and also as a binding strength improving material for back metal. In order to obtain a sufficient binding force, the amount of tin added is appropriately 2 to 5%.

Example Iron (Fe) 69%, kelmet powder 27%, tin powder 4%
% Of the mixed powder is spread on a steel plate to a thickness of about 3 mm, primary sintering is performed at 825 ° C., and then this sintered body is rolled at a rolling ratio of
% Primary rolling, secondary sintering was performed at 825 ° C., and then secondary rolling was performed at a rolling rate of 10%. As for the composition of the above-mentioned kelmet powder, one having a composition such that the mixed powder contains 17% of copper and 10% of lead is used.

FIG. 3 shows a process for producing an iron-based winding bush using the method of the present invention, in which (A) powder is mixed and (B) mixed powder is sprayed on a backing metal (steel plate). (C) Primary sintering in a sintering furnace,
(D) primary rolling, (E) secondary sintering, (F) secondary rolling, (G) cutting,
(H) Cylindrical forming, (I) Friction welding, Machining.

The bearing material manufactured in the above-mentioned example was applied to a scanning electron microscope (500
Fig. 4 shows the appearance when viewed in double. In this figure, 1 is iron of the base metal, 2 is a copper-tin alloy, and 3 is lead. From this figure, it can be seen that when lead is added with a kermet, molten lead moves and segregates in the sintered body. Without
You can see that it fits properly in the copper.

Also, the results of elemental analysis of the portion viewed with the scanning electron microscope with an X-ray microanalyzer are shown in FIGS.

FIG. 5 shows lead, FIG. 6 shows iron, FIG. 7 shows copper, and FIG. 8 shows tin. The white parts in the figure indicate the respective elements.

As is clear from these figures, it is understood that lead is fixed in the sintered body after sintering.

FIG. 9 shows a comparison of the friction coefficient between the sintered alloy according to the present invention and a conventional copper-based sintered alloy (JIS LB3C). In the figure, A indicates the present invention example and B indicates the conventional example. .

From this figure, it was confirmed that the sintered alloy according to the present invention has friction characteristics equal to or higher than those of LB3C.

EFFECTS OF THE INVENTION According to the present invention, a bearing material capable of joining an iron-based sintered alloy having a high self-lubricating property, a sufficient strength and a uniform structure to a back metal, and exhibiting a sufficient function as a bearing for high load. Can be obtained.

[Brief description of drawings]

1 (A) and 1 (B) are schematic views showing the components of the present invention before and after sintering, and FIGS. 2 (A) and 2 (B) are conventional iron-based sintered alloys. Schematic diagrams showing the components before and after sintering, FIG. 3 is a manufacturing process diagram of the rolled bush, FIG. 4 is a diagram showing a state observed by a scanning electron microscope, and FIGS. 5 to 8 are X-rays. FIG. 9 is a diagram showing a result of elemental analysis by a microanalyzer, and FIG. 9 is a diagram showing a friction coefficient.

Claims (1)

[Claims] 1. A main component of iron, 5 to 30 wt.
%, Tin 1 to 5 wt% mixed powder is spread on a steel plate, and then primary sintering is performed at 800 to 900 ° C., and then this sintered body is primary rolled to a predetermined density, and further 800 to 900 A method for producing a bearing material comprising an iron-based sintered alloy, which comprises secondary sintering at ℃ and secondary rolling thereafter.