Strengthening and Strength Uniformity of Structural Ceramics
Abstract
The goal of this work is to identify the processing flaws that limit the strength of sintered ceramics, and to engineer uniform microstructures which either eliminate or minimize the size of these processing flaws. During the first year, a major advance was made by uncovering the fact that agglomerates in powders produce crack-like voids that severely limit the strength of sintered ceramics. Crack-like voids produced by the differential sintering of agglomerates relative to their surrounding powder matrix can be the most detrimental strength degrading flaw in sintered ceramics. As detailed and summarized in the review prepared for a 1984 ASM Conference on Materials for Future Energy Systems, colloidal approaches to powder processing and consolidation can minimize the size of soft agglomerates (those that can be broken apart with surfactants) and hard agglomerates (eliminated by sedimentation of colloidal suspensions). Work has shown that the elimination of the large, soft agglomerates with surfactants increases the average strength of a transformation toughened Al2O3/30 v/o ZrO2 (2.5 v/o Y2O3) composite from 550 MPa (80,000 psi) to 930 MPa (135,000 psi).
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1984
- Accession Number
- ADA144302
Entities
People
- F. F. Lange