High-strength friction stir welding of selective laser melted AlSi10Mg alloys

Selective laser melted AlSi10Mg alloys with eutectic network structures were successfully joined by friction stir welding. Sound butt-lap joints have been achieved. A novel enlarged pin was designed to overcome kissing bonding defects and increase interfacial bonding area. The hook defect in a conventional butt-lap joint was avoided due to the limitation of the upward flow of interfacial materials, and the interfacial joining width was 2.5 times of the plate thickness. The eutectic Si network structure was broken into the re-dispersed rich-Si phases, improving joint performance. The ultimate tensile strength reached 83.1% of the matrix, higher than those of conventional melting techniques.