Chapter 44. Tensile Testing in the Development of Processing Methods for High Strength/High Reliability Silicon Nitride

  1. John B. Wachtman Jr.
  1. M. R. Foley and
  2. V. K. Pujari

Published Online: 26 MAR 2008

DOI: 10.1002/9780470313978.ch44

Proceedings of the 16th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 13, Issue 9/10

Proceedings of the 16th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 13, Issue 9/10

How to Cite

Foley, M. R. and Pujari, V. K. (1994) Tensile Testing in the Development of Processing Methods for High Strength/High Reliability Silicon Nitride, in Proceedings of the 16th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 13, Issue 9/10 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470313978.ch44

Author Information

  1. Norton Company, Northboro, MA

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1994

ISBN Information

Print ISBN: 9780470375198

Online ISBN: 9780470313978

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Keywords:

  • transformation;
  • crystallographic;
  • modified;
  • configuration;
  • stabilization

Summary

Injection molded and pressure cast net shape formed cylindrical buttonhead tensile specimens were tested for strength and reliability. The material being developed is a HIPed Y2O3—doped silicon nitride material with toughness of 6.2 MPa √m. Through multiple iterations the room temperature mean strength values have increased from 450 to over 900 MPa with a shift in Weibull Modulus for individual batches from 4 to over 20. Fractographic analysis paved the way for systematic elimination of major flaw types. Associated with the exceptionally high strengths has been a shift in failure originating flaw type from volume to surface which has prompted a review of machining procedures.