Strengthening Oxides by Reduction of Crystal Anisotropy

摘要

Ceramic bodies of crystals with reduced anisotropy were prepared using compositions in the system Al2O3-Cr2O3. The variation of strength with grain size was measured and compared with data for alumina bodies. The results were interpreted in terms of variations in grain shape and other microstructural features. The dimensions of mirrors in fracture surfaces of alumina and alumina strengthened by quenching were measured. Comparison of the flexural stress vs. mirror size curves was used to estimate the residual stresses in the surface of the quenched alumina. Using the information an experimental residual stress profile was constructed. One exceptional specimen strengthened by quenching had a flexural strength of 223,000 psi. (Author)