Novel method of resistance spot welding of aluminum base composite material

Abstract

The invention discloses a novel method of resistance spot welding of aluminum base composite material. A stainless steel sheet is added between an electrode and aluminum base composite material when resistance spot welding connection is carried out on the aluminum base composite material. When the resistance spot welding connection is performed by adding the stainless steel sheet between the electrode and the aluminum base composite material, the squeeze time is 0.4 to 1 S, the hold time is 0.4 to 1.2 S, the electrode force is 2000 to 3500 N, the welding time is 0.1 to 0.3 S, and the welding current is 1.2 to 1.8 kA. The method has the advantages that when resistance spot welding connection is carried out on the aluminum base composite material, a stainless steel sheet with certain thickness is added between the electrode and the aluminum base composite material, the welding process is simple, reinforced phase particles or crystal whiskers in a joint region are evenly distributed, the tension and shearing force of a resistance spot welding connector is obviously improved, the applicable scope of the welding machine is expanded, and the damage to the resistance spot welding machine equipment is reduced, therefore, the invention is an effective novel technology for resistance spot welding of aluminum base composite material, which has important application value.

Description

1. Technical field: [0001] The invention relates to a method for resistance spot welding, in particular to a new method for resistance spot welding of aluminum-based composite materials. 2. Background technology: [0002] Aluminum-based composite materials (such as SiCp / Al) containing reinforcing phases (such as silicon carbide particles, aluminum oxide particles, etc.) are currently the most widely used, fast-growing, cheap, and capable of large-scale production. A metal matrix composite material. At present, the aluminum-based composite material is constantly replacing traditional metal materials, and is used in aerospace, chemical industry, automobile industry, shipbuilding, electronic packaging and military industries that require high material performance. Therefore, the material has a large application prospects. However, due to the large difference in physical properties (such as melting point, thermal conductivity, expansion coefficient) and chemical compatibility ...

AI Technical Summary

Problems solved by technology

However, due to the large difference in physical properties (such as melting point, thermal conductivity, expansion coefficient) and chemical compatibility between the matrix and the reinforcing phase of aluminum matrix composites, welding is much more complicated than that of single-phase homogeneous materials. It is difficult to form high-strength welded joints

Therefore, the connection problem of the aluminum matrix composite material has been hindering the rapid development of this material and has become a serious obstacle to the practical application of this material.

However, the average diameter of the nugget formed under this process is small, only 4.3mm, which does not fully utilize the potential of the material; in addition, through the microscopic analysis of the welded joint, it is found that there is serious particle segregation in the nugget center of the welded joint phenomenon (see attached Figure 5 and 6 , since the reinforcement phase particles are a brittle phase, the segregation of the reinforcement phase particles will greatly reduce the toughness of this area)

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