Synthesis of Net-Shape Ceramic Matrix Composites from Phase Separated Polymeric Precursors.
Abstract
This program seeks means of fabricating thick cross-section monolithic and composite ceramic components using polymeric ceramic precursors, thereby realizing potential processing and quality advantages. This program's strategy for overcoming longstanding problems is based on developing and maintaining a precisely controlled interconnected pore structure within the reacting part, thus providing a pathway through which gaseous reaction products can escape without damaging the part and into which gaseous reactants can freely penetrate, enabling synthesis reactions to proceed uniformly at maximum rates. The approach taken is based on filling the void space within solid phase reactants because this option offers important opportunities for minimizing both shrinkage and residual porosity. During the past year this research has: (1) investigated whether inert fillers can be made to act as nuclei for reaction products formed from the polymeric ceramic precursors, (2) sought means to prevent migration of the reactive binders during drying, and (3) made reaction formed silicon nitride matrix composite parts using mullite fibers. Results indicate that the approach is viable. (MM)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1996
- Accession Number
- ADA304272
Entities
People
- Dietmar Seyferth
- John S. Haggerty
Organizations
- Massachusetts Institute of Technology