Accession Number : ADA332906

Title :   De-Sintering, A Phenomena Concurrent with Densification within Powder Compacts: A Review

Descriptive Note : Technical rept. for period ending Sep 96

Corporate Author : CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS

Personal Author(s) : Lange, Fred F.

PDF Url : ADA332906

Report Date : 30 SEP 1996

Pagination or Media Count : 13

Abstract : A morphological instability characterized by the separation of grain pairs and the disappearance of grain boundaries is a common feature in polycrystalline bodies that are constrained from shrinking during mass transport. This instability, know as de-sintering, occurs during grain coarsening as sequentially observed for thin films with columnar microstructures constrained by a substrate, fibers with a bamboo' microstructure constrained by a matrix, and powder matrices within composites. De-sintering is a common phenomena in partially dense, polycrystalline bodies; it occurs concurrently with densification phenomena and is emphasized in composites where the partially dense matrix is constrained from shrinking by a reinforcement network. De-sintering occurs in any lower density region were shrinkage is constrained by the average shrinkage of the body.

Descriptors :   *GRAIN GROWTH, PARTICLE SIZE, FIBERS, MICROSTRUCTURE, MORPHOLOGY, INSTABILITY, GRAIN BOUNDARIES, SINTERING, POLYCRYSTALLINE, SHRINKAGE.

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE