Measurements of Powder–Polymer Mixture Properties and Their Use in Powder Injection Molding Simulations for Aluminum Nitride

Abstract

Aluminum nitride has been favored for applications in manufacturing substrates for heat sinks due to its elevated temperature operability, high thermal conductivity, and low thermal expansion coefficient. Powder injection molding is a high-volume manufacturing technique that can translate these useful material properties into complex shapes. In order to design and fabricate components from aluminum nitride, it is important to know the injection-molding behavior at different powder–binder compositions. However, the lack of a materials database for design and simulation at different powder–polymer compositions is a significant barrier. In this paper, a database of rheological and thermal properties for aluminum nitride–polymer mixtures at various volume fractions of powder was compiled from experimental measurements. This database was used to carry out mold-filling simulations to understand the effects of powder content on the process parameters and defect evolution during the injection-molding process. The experimental techniques and simulation tools can be used to design new materials, select component geometry attributes, and optimize process parameters while eliminating expensive and time-consuming trial-and-error practices prevalent in the area of powder injection molding.