JP4709035B2 - Welding method for metal foam parts - Google Patents

Description

  The present invention relates to a method for welding a foam metal member, in which MIG arc welding or laser welding is used as a welding method, so that the weld metal members made of foam metal can be easily joined together.

  Foam metal is a porous metal material with a structure containing many pores (cells) in a light metal such as aluminum or magnesium. It is lightweight and has shock absorption, sound absorption / damping, heat insulation, etc. It has excellent features. Recently, foamed aluminum (foamed pure aluminum or foamed aluminum alloy), which is a representative of foam metal, is used for automobiles, vehicles, etc. for the purpose of taking advantage of its excellent impact absorption and strength / stiffness improvement effect by filling composite. It is being adopted as a frame filler.

  By the way, it is necessary to join foamed aluminum members with the expansion of the use of foamed aluminum. Welding joining is regarded as a promising joining method that can eliminate the disadvantages of bolts, nuts, or adhesives. ing. Although it has been announced at the conference that ultrasonic welding and improvement of weldability by magnetic fields are being carried out on the welded joint between the aluminum foam members, these are considered to be not industrially easy. . Moreover, according to the search by the internet, information about welding joint by spot welding between foam metals and welding joint by seam welding between foam metals can be found (Non-Patent Document 1).

  On the other hand, the present inventors butted the end faces of a pair of quadrangular columnar foamed aluminum members to form a butt line (butt welding line), and used an aluminum alloy filler wire (wire outer diameter: 1.2mmφ), butt welding is performed along the butt line by low current TIG arc welding with a welding current of about 60 to 120A, the butt end faces are partially melted and melted, and a pair of The foamed aluminum member was welded.

  As a result, a foamed aluminum member joint with a joint efficiency of 100% was obtained. However, in the TIG arc welding between the foamed aluminum members, it is very difficult to maintain the molten pool stably without being melted, and in order to maintain the molten pool stably, the welding speed, the feeding speed of the filler wire, and the arc The swing conditions (swing width, number of swings, etc.) must be frequently adjusted, skill is required, and the welding speed is as low as 3 to 5 cm / min.

Thus, in order to expand the application of foamed aluminum to various fields, it is necessary to make it easy to weld and join the foamed aluminum members.
Mitsubishi Materials High-Performance Materials, “Processing Foamed Metals”, [online], [Search February 1, 2006], Internet <URL: http://www.mmc.co.jp/nfac/hpm/okegawa/ OHP / products / happou / kakou.html>

  Accordingly, an object of the present invention is to provide a foam pool that can stably form and maintain a melt pool when welding metal foam metal members to each other, and can easily perform weld joint between metal foam members. It is providing the welding method of a metal member.

  In order to solve the above problems, the present invention takes the following technical means.

  According to the first aspect of the present invention, the end faces of a pair of foam metal members are butted together to form a butt line, and on the butt line, a metal plate-like filler material having at least the same main component as the foam metal member. The metal plate-like filler metal and the butt end faces are melted by MIG arc to obtain penetration, and the pair of foam metal members are welded together. It is a welding method.

  According to a second aspect of the present invention, in the method for welding a foam metal member according to the first aspect, the foam metal member is a foam aluminum member, and the metal plate-like filler material is an aluminum plate-like filler material. It is characterized by.

  According to a third aspect of the present invention, the end faces of a pair of foam metal members are abutted with each other with a metal plate-like filler material having at least the same main component as the foam metal member interposed therebetween, and the metal plate is irradiated by a laser. It is a welding method of a metal foam member characterized by melting the shape filler metal and the butt end faces to obtain penetration and welding the pair of metal foam members.

  According to a fourth aspect of the present invention, in the method for welding a foam metal member according to the third aspect, the foam metal member is a foam aluminum member, and the metal plate filler is an aluminum plate filler. It is characterized by.

  According to the welding method of claim 1 and claim 2, because the metal plate-like filler material is placed on the butt line formed by abutting the end faces of the pair of foam metal members, In the case of TIG arc welding using a filler wire, it is possible to easily and stably generate a MIG arc and to stably form and maintain a molten pool by the presence of the metal plate-like filler metal. Unlike welding, it is not necessary to frequently adjust various welding conditions during welding, and it is possible to easily perform welding joining between metal foam members. In addition, the MIG arc welding can be used with a higher welding current flowing through the welding wire than in the case of the TIG arc welding, and the welding speed can be improved (the welding time can be shortened).

  According to the welding method of claim 3 and claim 4, since the end faces of the pair of foam metal members are abutted with a metal plate-like filler material interposed therebetween, the metal to be melted by the laser Unlike the case of TIG arc welding using filler wire, various welding conditions are not frequently adjusted during welding because the molten pool can be stably formed and maintained by the presence of the plate-like filler metal. It is easy to weld and join the metal foam members. Also, laser welding with a high power density heat source can greatly improve the welding speed compared to the TIG arc welding.

  Examples of the present invention will be described below.

  In the present invention, a welding test was performed in which the foamed aluminum members 1 and 1 were welded together using MIG arc spot welding as a welding method. Table 1 shows the components and dimensions of the foamed aluminum members 1 and 1, the material and dimensions of the aluminum alloy plate-shaped filler metal 2, and the MIG arc spot welding conditions in this welding test.

  This welding test will be described. As shown in FIG. 1, the end faces of a pair of aluminum foam members 1 and 1 are butted together to form a butting line, and in this example, the thickness is 1.5 to 3 mm and the width is 10 mm at intervals of about 60 mm. X Place the aluminum alloy plate-shaped filler metal 2 having a length of 10 mm, perform MIG arc spot welding at each of these mounting points, completely melt the aluminum alloy plate-shaped filler material 2 and immediately below the above-mentioned The welding end test was performed by melting the butt end faces to obtain penetration and welding the foamed aluminum members 1 and 1 together. In FIG. 1, 3 is a MIG arc spot welding torch, and 4 is a welding wire.

  As a result, the presence of the aluminum alloy plate-shaped filler metal 2 can easily and stably generate a MIG arc, and can stably form and maintain a molten pool (aluminum alloy plate-shaped melt material 2). If there is no material 2, the cutting state is caused by the MIG arc). This makes it unnecessary to adjust welding conditions such as welding current, unlike TIG arc welding, which requires skill to frequently adjust filler wire feed speed and arc oscillation conditions during welding. The members 1 and 1 could be easily welded together. Moreover, it can be used by flowing a higher welding current through the wire 4 than in the case of TIG arc spot welding, and the welding time can be shortened.

  FIG. 2 is a schematic cross-sectional view of a welded joint between foamed aluminum members by the welding method of the present invention shown in FIG. As shown in the figure, partial penetration welding was performed. In the welding method of the present invention under the conditions shown in Table 1, the penetration depth was about 5 mm.

  FIG. 3 is a graph showing the relationship between the thickness of the aluminum alloy plate-like filler metal and the appropriate welding conditions for it in the welding method of the present invention under the conditions shown in Table 1. As shown in the figure, when the thickness of the aluminum alloy plate-shaped filler metal 2 is 2 mm, which is a representative value, the appropriate welding conditions are when the welding current is 100 A, the arc time is 1.5 seconds, and the welding current is 80 A. The arc time is 2.5 seconds, and the arc time is 3.5 seconds when the welding current is 60A.

  Example 1 described above is a welding method using MIG arc spot welding, but in the welding method of the present invention, as the plate-like filler material made of aluminum alloy, for MIG arc spot welding having a width of 10 mm and a length of 10 mm as described above. In place of the plate-like filler material 2, the plate-like filler material having the same length as the butt line (butt welding line) of the foamed aluminum members 1, 1 is placed on the butt line, whereby MIG It is also possible to perform seam welding of the foamed aluminum members 1 and 1 by arc welding. In this case, in order to prevent the molten pool from being melted in the latter half of the butt weld line, for example, the welding current may be gradually decreased as the welding progresses.

The end surfaces of the pair of foamed aluminum members 11 and 11 are abutted with each other with an aluminum alloy plate-like filler material 12 interposed therebetween (see FIG. 4), and along the longitudinal direction of the aluminum alloy plate-like filler material 12. In this embodiment, the plate-like filler material 12 is irradiated with a CO ₂ laser, and the aluminum alloy plate-like filler material 12 and the butt end faces can be melted and melted to form the foamed aluminum members 11, 11. A welding test was performed in which the members were welded (partial penetration welding with a penetration depth of about 5 mm). In this case, the laser beam used in the laser welding method for irradiating the laser is not particularly limited to the CO ₂ laser as long as it can give energy to the aluminum alloy plate-like filler metal 12. For example, a YAG laser, a semiconductor A laser, a fiber laser, etc. can be mentioned. Table 2 shows the components and dimensions of the foamed aluminum members 11 and 11, the material and dimensions of the aluminum alloy plate-shaped filler metal 12, and the CO ₂ laser welding conditions in this welding test.

  As a result, the molten pool was stably formed and maintained by the presence of the aluminum alloy plate-like filler material 12 melted by the laser. Thereby, unlike the case of TIG arc welding which requires skill to frequently adjust the filler wire feed speed and arc swing conditions during welding, it is not necessary to adjust the welding conditions. Welding joints between each other could be easily performed. Also, laser welding with a high power density heat source can greatly improve the welding speed compared to the TIG arc welding.

It is a figure for demonstrating the welding method of this invention. It is typical sectional drawing of the welding junction part of the foaming aluminum members by the welding method of this invention shown in FIG. In the welding method of this invention on the conditions shown in Table 1, it is a graph which shows the relationship between the thickness of the aluminum alloy plate-shaped filler metal, and the appropriate welding conditions with respect to it. It is a figure for demonstrating the welding method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 ... Aluminum foam member 2,12 ... Plate-like filler material made from aluminum alloy 3 ... Torch for MIG arc spot welding 4 ... Wire for welding

Claims (4)

  The end faces of a pair of foam metal members are butted together to form a butt line, and a metal plate-like filler material having at least the same main component as the foam metal member is placed on the butt line, and a MIG arc The metal plate-like filler metal and the butt end surfaces are melted to obtain penetration, and the pair of foam metal members are welded together.   2. The method for welding a foam metal member according to claim 1, wherein the metal foam member is a foam aluminum member, and the metal plate-like filler material is an aluminum plate-like filler material.   The end surfaces of the pair of foam metal members are abutted with each other with a metal plate-like filler material having at least the same main component as the foam metal member interposed therebetween, and the metal plate-like filler material and the bump are sandwiched by a laser. A method for welding a foam metal member, comprising melting the mating end faces to obtain penetration and welding the pair of foam metal members together.   4. The method for welding a foam metal member according to claim 3, wherein the foam metal member is a foam aluminum member, and the metal plate-like filler material is an aluminum plate-like filler material.

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