Product Code: PIC2008_704

Spot Joining of Magnesium using Laser Assisted Self-Pierce Riveting Technology
Authors:
Wei (William) Song, Cast Cooperative Research Centre, Swinburne University of Technology; Hawthorn Australia
Yvonne Durandet, Cast Cooperative Research Centre, Swinburne University of Technology; Hawthorn Australia
Brian Dempster, Cast Cooperative Research Centre, Swinburne University of Technology; Hawthorn Australia
Milan Brandt, Cast Cooperative Research Centre, Swinburne University of Technology; Hawthorn Australia
Stuart Blacket, Henrob (Uk) Pty Ltd; Geebung Australia
Presented at PICALO 2008

Spot joining of aluminium intensive vehicle bodies using self-pierce riveting (SPR) technology is well established with over 10 years of commercial application in the automotive industry. SPR is a promising technique for magnesium, especially for spot joining to dissimilar metals because the formation of brittle intermetallic phases encountered in resistance spot welding or laser welding is avoided. The challenge however is to overcome the poor ductility of magnesium at ambient temperatures and prevent cracking of the magnesium ply, especially when it is placed on the bottom in the design of the joint. This paper presents progress made in SPR joining of magnesium by using a laser to preheat the magnesium ply and assist its deformation. Magnesium-to-magnesium and aluminium-to-magnesium joints of various ply thicknesses and alloys included: 2 to 3mm thick high pressure die cast AM50 and AM60 alloys, 3.3mm thick strip cast AZ31-O, 2mm thick Al 5005-H34 sheet, and 1.5 or 3mm thick Al6060-T5 extruded plate. Results are presented on the quasi-static tensile shear strength of various joints produced at cycle times of less than 5s.