JPH06277854A - Method for joining short fiber reinforced metallic materials - Google Patents

Abstract

PURPOSE:To provide a joint part having high joint strength by setting a material of the same kind as a metallic base as an insert material in the joint part. CONSTITUTION:The material of the same kind as the metal base 3, for example, Al alloy or the like, is previously set as the insert material 5 in the joint part 4 and thereafter, the short fiber reinforced metallic materials 1 are resistance welded or friction welded to each other at the time of resistance welding or friction welding of these materials to each other. The thickness of the insert material 5 is specified to about 0.001 to 2mm. The metallic base 3 is an Al-Zn system and the short fibers are included at 25vol.% in the metallic base. As a result, the insert material 5 is melted during joining, by which the deficiency of the molten Al alloy of the metallic base 3 near the joint part 4 is made up and the joint strength is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining short fiber reinforced metallic materials.

[0002]

2. Description of the Related Art In the case of short fiber reinforced metal, defects are likely to occur when melt-welding and the joint strength is low. We are doing welding.

[0003]

As described above, conventionally, in order to assemble a short fiber reinforced metal material into a structural member, the short fiber of the joint portion should be removed in advance at the material design stage, or welding may be performed. Often attached. In the case of the former, it can be applied only to a certain target product, and the application range is narrow and the cost is high. Further, in the latter case, there is a problem in strength, and the advantage as the short fiber reinforced metal material cannot be exhibited.

In view of the above-mentioned state of the art, the present invention is to provide a joining method by which a joining portion having high joint strength can be obtained when a short fiber reinforced metal material mass-produced as a material is assembled into a structure. is there.

[0005]

In the case of a short fiber reinforced type metal material, when ordinary fusion welding (TIG, MIG, etc.) is performed, welding defects such as pores occur due to melting or evaporation of fibers. Therefore, we have conducted diligent research to join short fibers without melting as much as possible by using friction welding or resistance welding with a small melting width, but even in these joints, short fiber aggregation, change in orientation of short fibers or It was confirmed that the rod-shaped short fibers were broken into small pieces and were granulated, resulting in much lower bonding strength than the base material. Therefore, in order to solve these problems, if the same metal material as the short fiber reinforced metal material of the base material is used as an insert material in the joint portion in advance, and an appropriate joint material is selected,
Can be alleviated, and a joint with high joint efficiency can be obtained. Based on this finding, the present invention has been completed.

That is, the present invention is characterized in that, in resistance welding or friction welding of a short fiber reinforced metal material, a material similar to the metal base material is previously set as an insert material at the joint portion and joined. This is a method of joining metal materials.

[0007]

[Function] As a typical example of the short fiber reinforced metal material,
The metal base is an Al alloy, the short fibers are SiC whiskers (hereinafter,
Short fiber reinforced metal material (SiCw / abbreviated as SiCw)
Taking Al) as an example, the method of the present invention is shown in FIG. 1 and the conventional method is shown in FIG. 5, and the operation of the present invention will be described by comparing the two.

First, the conventional method shown in FIG. 5 will be described. FIG. 5A shows a short fiber reinforced metal material (Si
Cw / Al), FIG. 5 (b) is the same material after joining, FIG.
(C) shows an enlarged view of the joint portion A in FIG. 5 (b). In FIG. 5, 1 is a short fiber reinforced metal material (SiCw / Al alloy), 2 is a short fiber (SiCw), 3 is a metal base (Al alloy), and 4 is a joint.

In the conventional method shown in FIG. 5, a short fiber reinforced metal material (S) is usually used by resistance welding or friction welding.
iCw / Al alloy) 1 When joining together, the Al alloy of the metal base 3 near the joint 4 is melted and pushed out during the joining, so that the joint 4 is shown in FIG. 5 (c). Agglomeration of SiCw due to lack of Al alloy (SiCw
Causes that the bonding strength is considerably lower than that of the base metal (SiCw / Al alloy) due to changes in the orientation of the SiCw (direct direction with the base metal) and small breaks in the SiCw, resulting in problems such as granulation. Becomes

Next, one embodiment of the method of the present invention shown in FIG. 1 will be described. 1 (a), (b), and (c) correspond to (a), (b), and (c) of FIG.
Although the same parts as those in FIG. 1 are denoted by the same reference numerals, the description thereof will be omitted. In FIG. 1, 5 is a short fiber reinforced metal material (Si
An insert material made of an Al alloy of the same kind as the metal base (Al alloy) 3 of Cw / Al alloy) 1 is shown. The thickness of the insert material is generally 0.001 to 2 mm.

According to the method of the present invention shown in FIG.
When resistance welding or friction welding is carried out by sandwiching the insert material 5 in, the insert material 5 is melted during the joining, and the shortage of the molten Al alloy in the metal base 3 in the vicinity of the joining portion 4 is compensated.
The problems (1) to (4) (in particular, the prevention effect of) can be alleviated, and the bonding strength between the short fiber reinforced metal materials 1 can be increased.

[0012]

EXAMPLE An example of the present invention will be described below.
The metal base of the short fiber reinforced metal material used here is A7
075 (Al-Zn system), and the short fiber has a diameter of 0.1 to 0.15.
The length of SiCw is 0.5 × 0.2 to 10 μm, and 25 vol% of this short fiber is contained in the metal matrix. FIG. 2 shows a scanning electron micrograph (5000 times) of the structure of the short fiber reinforced metal material which is the base material. As is clear from FIG. 2, elongated SiCw are dispersed almost uniformly in the Al alloy (A7075) in the base material before joining.

As shown in FIG. 1, the base material was made of the same metal (A7075) as the metal base material of the base material and had a thickness of 0.
A 01 mm insert material was set between the base materials and resistance welding was performed. A scanning electron micrograph (5000 times) showing the structure of the short fiber reinforced metal material after welding is shown in FIG. From FIG. 3, it was confirmed that there is almost no agglomeration of SiCw and change in the orientation of SiCw due to the shortage of the Al alloy in the joint portion. In addition, as shown in FIG. 4, it was confirmed that the joint strength is also superior to the case where the insert material is not used.

Although the above examples are examples of resistance welding, almost the same effect was obtained in the case of friction welding.

On the other hand, a short fiber-reinforced metal material obtained by resistance welding the same base material as that of the embodiment by the conventional method shown in FIG. 5 without using the insert material of the same base material as that of the above embodiment. Scanning electron micrograph (50
00 times) is shown in FIG.

Comparing FIG. 6 with FIG. 3, it can be seen that in the conventional method, SiCw agglomeration, change in orientation of SiCw and Si
It can be seen that Cw is severely broken and granulated. Also, FIG.
As is clearer, it can be seen that the joint strength is inferior to that of the method of the present invention using the insert material.

[0017]

According to the present invention, the shortage of reinforcing short fibers due to the lack of a metal base in the joint portion, the change in orientation of the short staple fibers, the breaking of the short staple fibers, and the granulation are alleviated, and the joint strength is improved. The effect that can be achieved is exhibited.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is a scanning electron micrograph of the structure of a short fiber reinforced metallic material base material according to an embodiment of the present invention.

FIG. 3 is a scanning electron micrograph of the structure of a short fiber reinforced metallic material after joining according to an embodiment of the present invention.

FIG. 4 is a chart showing effects of the present invention.

FIG. 5 is an explanatory view of one mode of conventional joining of short fiber reinforced metal materials.

FIG. 6 is a scanning electron micrograph of the structure of a short fiber reinforced metal material bonded by a conventional method.

[Procedure amendment]

[Submission date] July 6, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

In the conventional method shown in FIG. 5, normally,
When short fiber reinforced metal materials (SiCw / Al alloy) 1 are joined by resistance welding or zero pressure welding, the Al alloy in the metal base 3 near the joint 4 is melted and extruded to the outside during joining. Therefore, as shown in FIG. 5 (c), therefore, the joint portion 4 is agglomerated with SiCw (Si
Cw comrades hardly junction), the change in orientation of SiCw (broken small base metal and straight angular direction) and SiCw, problems arise such as granulation, decreased significantly compared bonding strength to the base material (SiCw / Al alloy) Cause

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 4

[Correction method] Change

[Correction content]

[Figure 4]

Claims (1)

[Claims] 1. In a resistance welding or a friction welding of a short fiber reinforced metal material, a material similar to the metal base material is previously set as an insert material at the joint portion and joined, and the short fiber reinforced metal material is joined. Joining method.