Some properties of mullite-zirconium dioxide structural ceramics produced by the hip method from amorphous granules at elevated pressures

Amorphous granules of mullite - 10, 20, 30 wt.% Zr O2 have been produced under rapid quenching (the calculated cooling rate being between 103 and 105 C/s). The yield of amorphous granules grows with a decreasing granule diameter and an increasing Zr O2 content and ranges between 80 and 95% for average granule size of 400 to 600 μm. All granules of a diameter smaller than 300 μm are amorphous. The gasosstatic pressing of amorphous granules of the above-given compositions has resulted in the mullite ceramics with a dispersed tetragonal Zr O2, the density of which is 95% of the calculated value. Under optimum operating conditions, the mullite matrix is characterized by the structure homogeneity and grain uniformity (0.5 to 3 μm). The tetragonal Zr O2 grain size is less than 0.5 μm and is not resolved by the optical microscope