High-temperature oxidation of composite AlN-ZrB2-ZrSi2 ceramics

The high-temperature (to 1450°C) oxidation of AlN-ZrB₂-ZrSi₂ powders and compact ceramic materials with different contents of ZrB₂-ZrSi₂ solid solution in air is examined using scanning electron microscopy and differential thermal, thermogravimetric, x-ray phase, and x-ray spectrum microanalyses. It is established that the hot-pressed (practically porousless) ceramic materials have high corrosion resistance up to 1350–1400°C when scale components (individual oxides) interact with each other to form solid solutions based on aluminum oxide, zirconium oxide, and aluminum borate. These phases become sintered in the presence of the liquid B₂O₃ phase, self-reinforced scale being formed. __________ Translated from Poroshkovaya Metallurgiya, Vol. 47, No. 1–2 (459), pp. 196–203, 2008.