Metallic powder thermal diffusivity and conductivity estimation

Abstract

Throughout this project, the design of an experimental setup for calculating the thermal diffusivity and thermal conductivity of metallic powder is treated. Additionaly, a theoretical model is developed comparing the existing models in literature for understanding the particles interaction and estimating our powder effective thermal conductivity. A transient thermal simulation using the Finite Element Mehtod is performed to validate the designed prototype. The obtained values for the powder thermal diffusivity converge along time, although there is a stationary error that could be calibrated testing powders with known thermal diffusivity. For the studied case, a relative error of 11,3% is shown, which is considerably less than the ±30% relative error obtained by the literature reviewed. Powder effective thermal conductivity was estimated with an average relative error of 14,6% when lateral heat loss is considered, while a disproportionately high value was obtained when lateral heat loss was not computed. This project has been carried out in the Hewlett-Packard Company, at the 3D Printing Laboratory, and consequently, some data will not be available in this document due to confidential reasons.