Effective thermal conductivities of metal powders for additive manufacturing

Abstract

Effective thermal conductivities (ETCs) of five commonly used metal powders in additive manufacturing have been measured at temperatures up to 750 °C. The ETCs of Al-Mn-Sc and Ti-6Al-4V powders with different particle sizes are also investigated. When the temperature is lower than 300 °C, the ETC of metal powders is insensitive to the temperature and material. In contrast, when the temperature exceeds 400 °C, it increases significantly with increasing temperature and changes markedly dependent on the material. Additionally, in the lower temperature range, the larger size powders have higher ETCs, which is more pronounced for Al-Mn-Sc due to its higher thermal conductivity. In the higher temperature range, the larger Al-Mn-Sc powder shows higher ETCs than the smaller powder. In contrast, the smaller Ti-6Al-4V powder shows higher ETCs when the temperature exceeds 600 °C. The effects of temperature and particle size on ETC are investigated via particle morphology analyses.