Production of full density metal-matrix composites by a combined selective laser sintering/metal infiltration process

摘要

A three stage process has been developed for the rapid prototyping of fully dense Mg/SiC MMC components. The process is based on the production of a porous silicon carbide preform by the selective laser sintering (SLS) process. SLSis a rapid prototyping process which uses a faster scanned laser beam to selectively bond powder into a geometry specified by a CAD file. The porous green preform is prepared for infiltration by a binder removal and oxidation firing cycle. The process is completed with the pressureless infiltration of the matrix alloy into the preform under a controlled atmosphere. The selection of a magnesium alloy as an infiltrant yields a lightweight composite with high thermal conductivity. TMA analysis indicates that the coefficient of thermal expansion of the composite is suitable for use in electronic packaging applications.