Laser net shape welding

Over the last 40 years of laser welding practice, weld bead geometry always experiences a section of the weld bead slightly above or below the parent material surface. In this paper, a new concept - net shape welding is introduced, whereby the weld joint fusion zone is flat to the parent material surface. Experimental work was carried out to demonstrate net shape laser square butt welded mild steels sheets. Tensile test results show that the net-shape welds well outperform those with traditional weld bead geometry. Computational fluid dynamic and finite element models have been used to assist in the understanding of net-shape weld geometry formation and the superior mechanical properties. (C) 2011 CIRP.