Laser beam welding of CuZn open-cell foams

Porous metallic materials with cellular structures combine many physical and functional characteristics. This mixture of different properties makes these materials very attractive for the development of advanced applications, which are especially important in the biomedical, structural and functional engineering, and electrochemical fields. Because of their cellular structure, unconventional processing is becoming increasingly important for promoting the industrial applications of these materials. In this work, the welding of open-cell Cu60Zn40 [wt%] foams using a 1 kW continuous-wave fibre laser was investigated. During welding tests performed in the bead-on-plate configuration, a deterioration of the cellular structure was observed, with poor evidence for the joining of surfaces. In contrast, tests performed in the lap-joint configuration resulted in successful welding using a 1-mm-thick plate of the same material as the foams. The effect of the process speed on the geometrical characteristics of the transverse section of the joints was studied, and the heat-affected zone was evaluated via a hardness test. Finally, a compositional analysis of the weld bead was performed using a scanning electron microscope coupled with an energy dispersive spectrometer. The results of this study indicate that welding processes using a fibre laser can be utilised to join Cu-based foams. Weld beads in the lap-joint configuration were achieved due to the thin plate material filling the pore voids. (C) 2014 Elsevier Ltd. All rights reserved.