Thermal Processing of Injection-Molded Silicon Carbide

Silicon carbide is the most important and versatile non-oxide ceramic. Powder injection molding (PIM) is a method of high-speed fabrication of complex near-net shapes of SiC and other powders. Green micro-machining (GMM) is used to extend the shaping capability of green ceramics and powder metallurgy to smaller feature sizes. Debinding—removal of organic additives—is the rate-limiting step in PIM. Thermal Processing of Injection-Molded Silicon Carbide presents a study of the effects of GMM, debinding and sintering on two size distributions of PIM α-SiC with 5% each of Y2O3 and AlN sintering aids. The use of 10% 20-nm particles, i.e., a bimodal size distribution, to increase the packing density of the green bodies was found to have a small but mostly negligible effect on the rate of debinding, the liquidphase sintering (LPS) precipitates, the microstructural development and the mechanical properties of SiC compared to the conventional monomodal size distribution, where D50 = 0.7 μm. The nanoparticles and debinding methods did have a strong effect on the feasibility of GMM on SiC. The nanoparticles, debinding methods and GMM in combination significantly affected the sinterability of SiC. Monday, June 15, 2015 10:00, Rogers Hall 226 School of Mechanical, Industrial, and Manufacturing Engineering