The Alpha/Beta Silicon Nitride Phase Transformation.
Abstract
The literature on the relevance of the alpha/beta silicon nitride transformation to hot pressing of silicon nitride ceramics is briefly reviewed as are crystal structure data for the two phases. Also mentioned are published results on the kinetics of the alpha/beta phase transformation. The kinetics of the transformation were determined by quantitative X-ray analysis on low and high purity silicon nitride powders at 1600 C. The addition of magnesia enhanced the transformation rate while the addition of yttria did not. It is concluded that the transformation proceeds via a solution-precipitation mechanism and that alpha and beta silicon nitride are respectively low and high temperature forms. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1977
- Accession Number
- ADA044520
Entities
People
- Donald R. Messier
Organizations
- United States Army Research Laboratory