Injection Molding of Sinterable Silicon-Base, Nonoxide Ceramics

摘要

The program has resulted in a process for fabricating complex shapes of sinterable, silicon-based, nonoxide ceramic by injection molding a materials system consisting of submicron silicon nitride powder, sintering aids, and organic lubricant/binder. It is felt that this process also is capable of accommodating alternate sinterable materials and sintering aids. GTE Sylvania SN502 grade silicon nitride was chosen as the primary candidate material for the injection molding investigation. At the start of the program, SN502 best met the program prerequisites of commercial availability in large quantities and previously demonstrated sinterability. This material was used with yttrium oxide additions to develop a baseline injection molding composition from which processing and compositional variations could be made. A previously developed organic lubricant/binder system and binder extraction technique were used.