Product Code: ICAL06_107

Laser Joining of Steel-Aluminum Joints in T Configuration
Authors:
Jeroen van Tienhoven, University of Twente; Enschede Netherlands
B. Pathiraj, University of Twente; Enschede Netherlands
J. Meijer, University of Twente; Enschede Netherlands
Presented at ICALEO 2006

A laser joining process employing a Nd:YAG laser source, a cold wire feeder and a six axes robot has been developed to produce steel to aluminum transition joints. To obtain good strength, it is critical to minimize the formation of intermetallic phases at the joint. This has been achieved by a careful manipulation of the laser power and the laser beam position. This enabled the steel to be kept in a solid state while the aluminum is molten, thus restricting the formation of the intermetallic layer thickness to less then 5 µm. A good wetting of the steel by molten aluminum has been achieved by the use of an Al-12%Si filler wire and a zinc coated steel. Presence of zinc significantly improved the wetting and there was no need to use a flux. Joints were produced both in butt and T configurations. The results obtained with T joints are discussed in this paper. The process conditions were optimized to produce T joints with plates of 3 and 5 mm thickness. The joints had a breaking strength of about 150 MPa and the intermetallic layer.