Microstructure and Properties of Sintered Reaction Bonded Silicon Nitride with Aligned Whisker Seeds

Abstract:

Sintered reaction bonded silicon nitride with aligned whisker seeds was prepared by tape casting silicon slurry with 5 wt% b-Si3N4 whisker seeds followed by nitridation and sintering. Three different sintering additives were used for the samples; 7 wt% Y2O3, 6 wt% Y2O3 + 1 wt% Al2O3 and 5 wt% Y2O3 + 2 wt% Al2O3. The sample with 5 wt% Y2O3 + 2 wt% Al2O3 showed the fastest a to b phase transformation after nitridation and the highest fracture toughness and flexural strength after gas pressure sintering among the samples. It also had finer microstructure than the other samples after sintering at 2248 K and at 2273 K. The finer microstructure was related to the faster phase transformation after nitridation, which resulted in the higher flexural strength.

• Periodical: Key Engineering Materials (Volume 287)
• Pages: 271-276
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.287.271
• Online since: June 2005
• Authors: Dong Soo Park, Byung Dong Hahn, D.-J. Baik
• Keywords: Aligned Whisker Seeds, Microstructure, Property Analysis, Reaction Bonded Silicon Nitride

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