JPS63137106A - Composite member and its production - Google Patents

Abstract

PURPOSE:To produce a securely joined composite member at a low cost by providing a recess having a specific shape to the joint surface of the metallic member at the time of joining the metallic member and metal powder sintered body. CONSTITUTION:The recess 5 is provided at >=1 points in part of the joint surface 4 where the metallic member 1 having >=35kg/mm<2> yielding point or yield strength is joined to the composite sintered metal body. The depth of the recess 5 is specified to >=1mm and the angle alpha thereof with the perpendicular face of a corner part 6 to 1-45 deg.. Such metallic member 1 with the recess 5 faced upward is inserted into a lower punch 8 of a metallic mold 9 and metal powder 3 is packed on the metallic member 1. The powder is then pressurized and compressed by an upper punch 7 and a lower punch 8. The composite body composed of the metallic member 1 and the metal powder molding 3 is thereby obtd. This composite body is sintered in a vacuum atmosphere, by which the securely joined composite member is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for joining a metal member made by forging or cutting, and a metal powder sintered body. - [Prior art] 1, + s: 4p Since then, metal members and metal powder sintered bodies have been joined by brazing them together, or by forming metal powder compacts formed on the metal member in a separate process. There are two known methods: sintering by placing metal on the material, and joining by impregnating a low-point metal during sintering.

[Problem that the invention seeks to solve]

The brazing method involves sintering the metal powder compact, then
Since brazing requires a process, there are problems in that the process is long and that it is not economical because it requires a brazing material. In addition, in the case of a method in which a metal powder compact is placed on a metal member and sintered, or a method in which a low melting point metal is impregnated during sintering, positioning not only takes time and effort, but also
Care must be taken to ensure that the metal powder compact and the metal member do not separate when inserted into a sintering furnace, which poses problems in terms of workability and low yield of good products. Further, no matter how careful one is, there is a problem in that some positional deviation occurs during movement within the sintering furnace, resulting in poor positional accuracy.

[Means to solve the problem]

□゛The present invention solves the above problems and provides a method for simultaneously integrating a metal powder molded body and a metal member in order to shorten the process, have excellent workability, and improve joint position accuracy. It is.

Hereinafter, the present invention will be explained in detail using the drawings.

An example of a composite member obtained by the present invention is shown in FIG.

To explain the mold used, the inner shape of the die 9 of the metal powder molding die must be the same shape as the outer circumference of the metal member 1 to be joined, but the outer circumference of the metal member and the inner circumference of the die must be the same. It is desirable that the clearance is in the range of 0.1 to 0.01 mm.

If the clearance is less than 0.01mm, it will be difficult to insert the metal member into the mortar, and if it exceeds 0.11mm, the metal powder will get caught in the gap between the metal member and the mortar during metal powder molding. , which is not preferable because it causes seizure of the mold.

On the other hand, the relationship between the outer periphery of the metal member and the mold is as described above, but as shown in FIG. It is essential. The size and number of these recesses are not particularly limited, but 1
Sufficient bonding strength can be obtained if there are at least two locations.

The concave portion is formed by forming the metal powder compact 3 after forming the metal powder using a mold.
This plays an important role in not only preventing lateral displacement between the molded metal powder body and the metal member 1, but also preventing separation of the metal powder compact and the metal member 1. If only to prevent lateral displacement, it is possible to provide a protrusion as shown in Fig. 3 on the joint surface of the metal member, but in this case, the metal member may be removed from the mold after powder compaction. Because the component and the metal powder compact are easily separated,
This is insufficient to achieve the purpose of the present invention.

The reason for this is that the metal powder that is compression-molded in the mold has a springback effect, and when the metal member and the metal powder molded body are taken out of the mold as they are, the metal powder molded body is pushed outward. It acts as a pushing force. Therefore, it is presumed that this is because when a metal member having a convex portion as shown in FIG. 3 is used, the metal member and the metal powder compact become easier to separate.

On the other hand, when a metal member is provided with a recess as shown in Fig. 2, the powder compressed in the recess presses the joint surface of the metal member due to springback.
This acts as a force for bonding the metal member and the metal powder compact.

Next, regarding the recess side angle α, it is important that this angle is in the range of 1 to 45° with respect to a plane perpendicular to the metal member joining surface.

If the angle is less than 1°, there is a problem that not only the metal powder may not be completely filled into the recess, but also cracks are likely to occur in the corner portion 5.

This seems to be due to the fact that the compacting density of the metal powder in the upper layer and the compacting density of the corner part are significantly different. On the other hand, if the angle exceeds 45°, the above-mentioned springback escapes upward, resulting in insufficient bonding force between the metal member and the metal powder compact, and the metal powder compact and the metal member tend to separate.

Therefore, the angle needs to be in the range 1 to 45'. The depth of the recess needs to be 0.5 mm or more. If it is less than this, the bonding force due to spring variation becomes weak and separation becomes easy, so the value is -71.y. Usually, this depth is taken into consideration based on the thickness of the metal powder compact, but if the thickness of the compact is 3 mm or more, the depth may be in the range of 30 to 50% of the total thickness.

The end surface of the metal member opposite the joint surface needs to be supported by the lower bunch 8 of the mold and to be able to withstand the pressure from the lower punch, and as long as this condition is met, especially There are no other restrictions. However, it is desirable that the yield point or yield strength of the metal member is 35 kg/mm' or more.

This is because if it is lower than this, the metal member inserted is likely to be deformed by the molding pressure during metal powder compression molding.

Although such a composite member can be used in various ways, the composite member of the present invention is particularly effective for parts such as valve lifters that require different characteristics for the upper and lower parts.

In addition, when combining metal parts, it is necessary that the sintering temperature of the metal powder compact is low, and the melting point of the metal part is low. It can be used for. Further, the metal powder referred to herein may be a single metal powder, an alloy powder, or a mixed powder obtained by mixing various metal powders. Further, the metal powder is coated with a lubricant such as zinc stearate at 0.00%.
It is desirable to mix 5 to 1%.

This is to maintain lubricity with the mold.

[Effect]

By using a metal member having one or more recesses as described above, a composite member in which a metal powder sintered body and a metal member are firmly joined can be manufactured at low cost.

[Example 1] 345C1 carbon steel with a yield strength of 55 kg/mm was machined into the shape shown in Fig. 2 with an outer diameter of 351IIIlφ, a thickness of 15 mm, an outer diameter of the concave portion of 10φ, and α of 30′ and a depth of 4 mra. , the same material has the shape shown in Figure 3 and the outer diameter,
The thickness, etc. are the same as above, and the tip of the convex part is 10
+nmφ was prepared. First, the metal member shown in FIG. 2 was inserted, and the opposite end surface was set so as to be supported by the upper surface of the lower punch.

On the other hand, the composition is 17% Cr, 3% C, and the balance is Pe.
and unavoidable impurities were prepared. This powder was filled into a set mold mortar, and then the powder and metal member were compressed under pressure from above and below using an upper punch and a lower punch as shown in FIG. The molding pressure at this time was 6t/cof.

After compression molding, the combined body was taken out of the mold, but the bond between the metal powder molded body and the metal member was strong and did not separate. The composite of the metal member and metal powder compact thus obtained was placed in a vacuum atmosphere of LQ-'Torr at 1230°C.
As a result of sintering at a temperature of 50°C, a strongly bonded composite member could be obtained.

However, when the prepared metal powder is compression molded using a metal member having convex portions as shown in Fig. 3, the metal powder compact and the metal member separate immediately after being taken out of the mold. have done.

[Example 2] Figure 6 shows the intended composite member.

The metal member shown in Figure 6 has an outer diameter of 355mφ and a lower inner diameter of 3φ.
, a metal member made of Cr tli with a height of 50 mm, a of 203, a recess depth of 3 a + m, and a yield strength of 90 kg/mm2, and a comparative example with the same shape and a yield strength of 25 kg/mm2.
A metal member made of III11″ mild steel was prepared. Powder having the same composition as the metal powder used in Example 1 was compression-molded in the same manner as in Example 1. As a result, the metal member made of Cr steel did not deform. Although the original shape was maintained, in the case of the comparative material made of mild steel, the foot portion 10 was deformed and the overall length was shortened.

FIG. 7 is a diagram showing a composite member according to the present invention being compressed by an upper bunch and a lower punch.

〔effect〕

In the composite member thus obtained, alloys having different properties can be used for the metal powder sintered body part and the metal member. Therefore, for example, by maintaining the strength with the metal member and using a material with high wear resistance in the powder sintered body part, it is possible to apply it to parts such as valve lifters.

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of one shape of the composite member obtained in the present application. FIG. 2 shows a metal member used in this application, and FIG. 3 shows a comparative example of the metal member used in this application. 4th.
FIG. 5 shows a process diagram for making a composite member having the shape shown in FIG. FIG. 6 shows the composite member obtained in the example shown in FIG. 2 of the present application, and FIG. 7 shows the composite member obtained in FIG. 6 in a compressed state. 1: Metal member 2: Metal powder sintered body 3:
Metal powder compact 4: Joint surface 5: Concave part
6: Corner part 7: Upper bunch
8: Lower bunch 9: Mortar 10: Foot agent Tetsuji Patent attorney -・1- Figure 1 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (4)

[Claims] (1) A composite member formed by joining a metal member and a metal powder sintered body, characterized in that one or more recesses are provided in a part of the joint surface of the metal member. (2) In a method of manufacturing a composite member by joining a metal member and a metal powder sintered body, one or more recesses are provided in a part of the joint surface of the metal member, and the metal Insert the metal member into the powder molding mold so that the lower end surface of the metal member is received by the lower punch of the molding press, fill with metal powder from above, compress the metal member and metal powder with the upper and lower punches, and take it out of the mold. A method for manufacturing a composite member, comprising: sintering the metal member at a temperature below the melting point of the metal member. (3) The yield point or yield strength of the metal member is 35kg/mm^
Claim No. 2 characterized in that there are two or more parts.
) The method for manufacturing the composite member described in item 2. (4) The recess on the joint surface of the metal member has a depth of 1 mm or more, and the side surface thereof is 1 mm or more with respect to the vertical plane to the upper end surface of the metal member.
The method for manufacturing a composite member according to claim 2, wherein the angle is 45 degrees.