Influence of power distribution on weld seam quality and geometry in laser beam welding of aluminum alloys

Abstract

In laser beam welding of aluminum alloy there is a high susceptibility of pore formation at low feed rates. Porosity can be improved by application of several laser spots to form the shape of the vapor capillary. In this regard, flexible, concentrically arranged laser spots with variable power distribution have recently been developed. Nevertheless, the influence of power distribution on weld quality and geometry has not been investigated. Therefore, this paper presents investigations regarding the influence of power distribution on the weld seam properties like penetration depth, seam width and porosity. Welding trials are carried out with three different aluminum alloys EN AW-1050, EN AW-6082 and EN AW-5083. Compared to a mono-spot the porosity can be reduced from 12 % to 8 % with power distribution of 75/25 of inner core and outer ring.