Product Code: ICAL07_803

CW Nd:YAG Laser Welding of Dissimilar Sheet Metals
Authors:
C van Rooyen, CSIR South Africa; Pretoria Republic of South Africa
Maritha Theron, CSIR South Africa; Pretoria Republic of South Africa
LH Ivanchev, CSIR South Africa; Pretoria Republic of South Africa
Presented at ICALEO 2007

A 4kW CW Nd:YAG laser was used for lap welding of three different dissimilar metal combinations, namely 316L S/S - Ti64, 316L S/S - Al 5052 and Al 1200 Cu (99.85%). A welding matrix of power, travel speed and spot sizes was investigated. The welded samples were studied and evaluated by means of X-rays, stereo and optical microscopy, SEM analyses, micro-hardness testing as well as sub-size tensile testing in order to recommend continuous welding parameters for lap welding of these 0.9mm thick dissimilar metal sheets. Sound welds could be obtained between the stainless steel and titanium (stainless steel on top) at different spot sizes (0.3 0.6mm ) between ~1.3 and 3kW, but the smaller spot sizes resulted in more weld instability. In the case of aluminum and copper (aluminum on top), stable welds were obtained only with the smaller spot sizes between ~1.3 and 2.5kW. Severe instability was experienced with the lap welding of stainless steel and aluminum and stable welds were mainly obtained at the bigger spot size (0.6mm) at ~1 to 2kW. Continuous lap welding parameters for these dissimilar metal combinations were, therefore, determined.