Strengthening and Strength Uniformity of Structural Ceramics.
Annual rept. no 2. 1 Feb 82-31 Jan 83,
ROCKWELL INTERNATIONAL THOUSAND OAKS CA SCIENCE CENTER
Pagination or Media Count:
Stresses created by differential sintering, due to differences in initial bulk density, were determined experimentally. The experiments entailed determining the shrinkage rates of a powder isostatically pressed to two different bulk densities. Using this information, stresses were determined by forcing the slower densifying compact to shrink at the same rate as the faster densifying compact and measuring the resulting forces with a load cell. Maximum stresses between 200 and 400 psi were observed to occur in the intermediate stage of densification. Despite larger differential strains at higher temperatures, stresses decreased to zero at the latter stage of densification. Viscoelastic experiments, of the stress relaxation type were performed. Results showed that the sintering specimen was more rigid at lower temperatures and more fluid-like at higher temperatures, to explain the development of maximum stresses at intermediate temperatures.
- *CERAMIC MATERIALS
- MATHEMATICAL MODELS
- REACTION KINETICS
- PHASE TRANSFORMATIONS
- STRUCTURAL ANALYSIS
- ISOSTATIC PRESSING
- BULK MATERIALS
- STRESS RELAXATION
- Ceramics, Refractories and Glass
- Fabrication Metallurgy