Laser Powder Bed Fusion of Bismuth Telluride: Process-Structure-Property Relationships

Thermoelectric generators possess a vast potential for waste heat recovery. Yet, the traditional fabrication methods of thermoelectric structures suffer from material loss and are limited to planar geometries. As a solution, laser additive manufacturing of thermoelectric materials has attracted considerable attention. In this research, the process-structure-property relationship of laser processed bulk bismuth telluride parts has been explored. Under constant laser power and scan speed, the effects of variation in scan pattern, number of scans, hatch spacing and layer height on the microstructural and thermoelectric properties were investigated. It was concluded that the laser powder bed fusion enables formation of intensive interfaces with preferential grain growth and certain scan patterns result in enhancement in relative density and thermoelectric properties.