Product Code: ICAL09_1601

Laser Beam Welding of Dissimilar Materials (Invited Presentation, 20 minutes)
Authors:
Rongshi Xiao, Beijing University of Technology; Beijing Peoples Republic of China
Peng Dong, Beijing University of Technology; Beijing Peoples Republic of China
Kai Chen, Beijing University of Technology; Beijing Peoples Republic of China
Presented at ICALEO 2009

In the modern industrial fields, there is a tendency that more and more parts or structures are compositely made of dissimilar materials, which offers challenges to the joining technology. In this paper, a review of laser beam welding of some dissimilar materials is presented based on the research of the authors group. The dissimilar material combinations researched include W-Cu PMM/stainless steel, brass/copper, brass/steel, aluminium/titanium, aluminium/copper and aluminium/steel. To join W-Cu PMM and stainless steel, the laser welding process with filler powder was conducted and a firm weld bead free of cracks was successfully obtained using Ni35 as the filler material. Deep penetration mode laser welding could be achieved in the joining of brass and copper with a Nd:YAG laser, adopting lap joint with brass on the right side, by utilizing the easily vaporizing of the zinc element in brass. For the jointing of dissimilar materials with great differences in the melting temperature and metallurgical properties, such as brass/steel, aluminium/titanium, aluminium/copper and aluminium/steel, a so-called laser penetration brazing (LPB) process has been proposed and researched. The substrate with lower melting temperature is penetratingly melted by the focused laser beam while the substrate with higher melting temperature is still kept in the solid state. The melted metal wets the solid substrate on the butt joint surface to form a brazing joint.