Highly densified bodies from preceramic polysilazanes filled with silicon carbide powders.

摘要

The preparation of highly densified ceramic bodies by the sintering of certain preceramic polysilazanes filled with silicon carbide powders, metal-containing sintering aids and, optionally, polysilazane curing agents is described. Such highly densified ceramic bodies can be prepared by either a pressureless sintering process or a hot press sintering process. The compositions of this invention can be formed into desired shapes and then sintered to form ceramic, shaped bodies with high densities. One advantage of the present invention is that the green bodies have relative high strengths and thus can be easily handled and, if desired, machined before sintering. The preceramic polysilazanes useful in this invention must yield ceramic chars which contains free or excess carbon in addition to carbon in the form of silicon carbide upon pyrolysis to elevated temperatures.