Study on laser welding of AA1100-16 vol.% B4C metal-matrix composites

Laser welding of AA1100-16 vol.% B4C metal-matrix composites was explored in the study. It was found that most B4C particles were decomposed and that needle-like AlB2 and Al3BC phases were substantially formed during the welding process without filler. Consequently, a joint efficiency of 63% (UTS) was obtained. The addition of Ti with 150 mu m thick foil increased the joint efficiency to 75% due to the decrease of needle-like phase formations. On the other hand, the addition of Ti with filler wire did not show significant tensile property improvement due to the Ti segregation and microstructure inhomogeneity in the weld zone. The fracture surfaces of laser welded joints were investigated to understand the fracture mechanisms. (C) 2011 Published by Elsevier Ltd.