Modeling the Selective Laser Melting of Multi-Component Thermoelectric Powders

Thermoelectrics enables thermal and electrical energy conversion or device cooling without any moving parts. It has remained a significant challenge to manufacture compact and high performance thermoelectric modules in a large volume using the conventional methods because of their drawbacks in practice, such as the long processing time and misalignment of individual thermoelectric elements. Selective laser melting (SLM) based additive manufacturing approach might offer a unique method to fabricate the low cost, reliable, highly efficient, scalable, and environmentally friendly thermoelectric modules. To understand the thermodynamic and hydrodynamic phenomenon during the SLM processing is of critical importance to ensure high quality products. In this paper, we developed a model which can be used to guide the SLM manufacturing of thermoelectric material with other nanoparticles embedded for higher thermoelectric performance. This physical model based on the continuous equations had the ability to analyze the fluid flow driven by buoyancy force and surface tension, which can be used to analyze the influence of the process parameters on the pool size, particle segregation, as well as temperature distribution within the powder bed. This information is very useful for developing robust SLM for thermoelectric device fabrication.