THE ROLE OF NITROGEN IN THE INTERGRANULAR GLASS PHASE OF SI3N4 ON HIGH-TEMPERATURE APPLICATIONS AND WEAR

[摘要] The hot hardness of Si3N4 tool materials of the CeO2 and CeO2-AlN doping systems, oxidation in air from 900 to 1450-degrees-C, and turning of tool steel with ceramic inserts of the same compositions were investigated to determine the effect of the N content of the intergranular phase. Si/N grain boundary diffusion was found to be the main controlling mechanism at high temperature for densification, mechanical behavior and chemical degradation of these materials in air, the passivation oxidation rate of the CeO2-AlN-Si3N4 system being dependent on the atomic fraction of N of the intergranular phase, with lower values for the N-rich compositions.

[发布日期] 1993-08-30

[效力级别]  Proceedings Paper