Selective Laser Melting of a Bismuth Telluride Thermoelectric Materials

Selective Laser Melting (SLM) technology is a rapidly growing solid freeform fabrication tool because it is cost effective, reduces production time of complex shapes, and accommodates a range of material systems such as metals, ceramics, polymers, intermetallics and composites. This work presents the first-ever results for SLM performed on a semiconducting thermoelectric material, bismuth telluride (Bi2Te3), using a Nd:YLF pulsed laser. The evolution of the localized melt lines formed under different processing parameters such as laser power and scan speed was investigated. Melt lines were evident on the top surface of the powder compacts under all investigated processing conditions. However, cross-sections taken across the melt lines revealed material removal at the irradiation site with minimum consolidation in the subsurface. Experimental results demonstrate that it is possible to laser melt Bi2Te3 powder, which enables new possibilities in additive manufacturing of 3D semiconductor thermoelectric components.