Authors:
Peter Haglund
Department of Engineering Sciences and Mathematics, Luleå University of Technology and Westinghouse Electric Sweden AB, SE-721 63 Va¨sterås, Sweden

Ingemar Eriksson
John Powell
Alexander Kaplan
Department of Engineering Sciences and Mathematics, Luleå University of Technology

A new laser welding process is presented which delivers a porosity free, spatter free weld. The process involves a donut shaped melt with a central hole of the same order of magnitude as the material thickness. The laser illuminates only the leading section of this melt. The hole is kept open by the melt surface tension.