Anomalous grain growth during hot isostatic pressing of magnesia ceramics made from starting powders with different coarse/fine mixing ratios

The influence of coarse powder on grain growth during hot isostatic pressing (HIP) was examined. Powder mixtures containing 0%, 0.5%, 5% and 20% coarse powder were prepared. The magnesia sintered without pressure was subjected to HIP at 1600°C for 0.5h at different pressures. The samples produced from fine powder had the largest grains after HIP treatment, although they had the smallest grains before it. The optical transparency of the HIP-treated magnesia ceramics increased with grain size. [Copyright &y& Elsevier]