Pressureless sintering behavior of injection molded alumina ceramics

The pressureless sintering behaviors of two widely used submicron alumina (MgOdoped and undoped) with different solid loadings produced by injection molding have been studied systematically. Regardless of the sinterability of different powders depending on their inherent properties, solid loading plays a critical role on the sintering behavior of injection molded alumina, which greatly determines the densification and grain size, and leads to its full densification at low temperatures. As compared to the MgO-doped alumina powder, the undoped specimens exhibit a higher sinterability for its smaller particle size and larger surface area. While full densification could be achieved for MgO-doped powders with only a lower solid loading, due to the fact that MgO addition can reduce the detrimental effect of the large pore space on the pore-boundary separation.