JPS5992161A - Joining method of sintered metal - Google Patents

Abstract

PURPOSE:To produce a composite sintered part having an intricate shape at a good yield by providing a recessed well for a brazing material on the surface of at least one sintered body that is in contact with the other constituting element, bringing the sintered bodies into contact with each other and heating the same in the state of attaching the brazing material near the joint part thereof. CONSTITUTION:Two sintered bodies 1, 9 are prepared. A recessed well 8 for a brazing material having >=0.5mm. thickness is beforehand provided by a metallic mold on the body 9 having holes 4, 4'. The body 1 is pressed onto the body 9 having the well 8 on the top surface and a brazing material 3 is inserted into a through-hole 7. When the bodies are heated to about 1,150 deg.C in an atmosphere of endothermic converted gas after the insertion, the bodies 1, 9 are thoroughly joined. The yield of production is 99.9%. The yield in the case of providing no well 8 is about 90%.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Technical Field The present invention relates to a method for manufacturing a sintered metal part in the shape of a multi-piece T1 by joining a plurality of parts with brazing material.

(b) Background of the technology Iron-based sintered parts have been put to practical use in automobiles, home appliances, office machines, etc., and the range of their applications is expanding more and more, and the required performance is becoming more stringent.

Among these applications, the present invention can be used to produce parts with complex shapes that cannot be formed in a single mold using a mold, such as parts with a cavity on the inner surface of the part, or parts with a stepped shape and a constriction in the center, at a low cost and in large quantities. It is intended to be manufactured in Conventionally, complicated parts such as sintered parts have been manufactured using methods such as machining after sintering or static pressure molding, but the disadvantage of both methods is that they are extremely expensive.

In order to solve this problem, one of the inventors of the present invention has developed a through hole (Fig. 1, 7) for filling the brazing material into the opening (Fig. 1, 1) of two or more molded bodies or sintered bodies. A method for joining sintered metals is proposed in which a powdered or molded brazing material 8 is placed in the through hole, and the soldering material 8 is heated and melted to a temperature higher than the melting point of the brazing material to perform joining and sintering. (Special application 1976-1652
No. 40, Japanese Patent Publication No. 57-4/4.4.4.8, Japanese Patent Application No. 13.322'3 and Japanese Patent Application No. 1987-], 66
(No. 4.53) However, although these methods can join parts with relatively simple shapes with good yield, they do not work well with complex shapes, especially when one component has holes that are important in the final product. In some cases, the brazing material may seep into the outer periphery (Fig. 1, 5') or flow into the hole, clogging the hole (Fig. 1, 5), causing problems in mass production. They often produce good quality products. In general, the amount of brazing material melts varies depending on the temperature and atmosphere, and there is a problem in that excess brazing material overflows, making it impossible to obtain a good finished part. On the other hand, if the amount of brazing material is too small, the brazing material will not sufficiently penetrate into the contacting joint surfaces, resulting in insufficient joint strength, which is a fatal problem.

(c) Purpose of the Invention The present invention relates to a method for solving the above-mentioned problems, and is capable of manufacturing complex-shaped composite sintered parts with a high yield.

) Disclosure of the invention The joining method of the present invention will be explained based on FIG. 2.

A through hole 7 for inserting the brazing material 3 is provided in the component l to be joined, and the holes 41.4. A brazing material pool 8 of an appropriate depth is provided on a part of the joint surface 6 of the other component 2 having a temperature of 1000, and heated while in contact with each other as shown in the figure. The soldering material is melted and the soldering material is allowed to penetrate into the joining surface 6.

In the above, the component may be a molded body, a sintered body, a combination of a sintered body and a sintered body, or a combination of a sintered body and a steel component. When a molded body is used, sintering is performed simultaneously with bonding. According to the method of the present invention, even if the amount of brazing material exceeds the required amount, it will not protrude to the outer periphery of the joint and will not flow into the holes 4, 4, and 4' and block them, making it possible to manufacture with a high yield. This is because the remaining brazing material is absorbed into the brazing material pool 8.

As a result of various experiments, it has been found that a depth of 0.5 rnf/L or more is preferable since it is not effective if the depth of the rotary drainage pool is too shallow.

Further, the number of depressions may be any number as long as it does not affect the properties of the final product. Although the above explanation is for the case where the members to be joined have through holes, the brazing material does not necessarily need to be placed in the through holes and can be applied to members without through holes.

Next, the effects will be explained using examples.

Example In order to manufacture a side plate as an iron-based sintered part, a molded body with a composition of 2% Cu-0.8% C1 balance Fe and a molding density of 6.5 J'/cm8 was used as component t49 in FIG. Got ready. In this case, in the element 9 having the holes 4., 4.', a brazing material reservoir having a depth of 0.8 as shown in the figure was provided in advance by a mold. The brazing material 3 was inserted into the through hole 7 and heated at 1150° C. in an endothermic modified gas atmosphere using butane gas as a raw material. The components taken out from the furnace were fully bonded and could be manufactured with a high yield of 99.9%. On the other hand, when the molded body of the same composition is not provided with the brazing material pool 8 as shown in FIG. 2, the yield is about 90%, and there are many holes that are clogged and protrusion to the outer periphery.

410 Brief Explanation of Drawings FIG. 1 is a cross-sectional view for explaining the conventional joining method, and FIG. 2 is a cross-sectional view for explaining the joining method of the present invention.

1.2.9; Component, 3; Brazing material, 41.4. ': Hole, 5: Hole blockage, 6: Joint surface, 7: Through hole, 8: Filler metal reservoir.

A1 Leap Way 2 Seki -383-・

Claims (1)

[Claims] A concave brazing material pool is provided on the surface of the body or the sintered body that comes into contact with other components, and the brazing material is heated and soldered with the brazing material placed near the joint with the other component. A sintered metal joining method characterized by joining each component by infiltrating the material. (2. In the manufacturing method described in claim (1), the sintered metal joining method is characterized in that the depth of the brazing material pool is 0.5 m or more.-