Effect of compositional variation in sintering behaviour of Al–Zr oxide composites

Abstract

Sintering behaviour of sequentially varied metal ion concentration in Al x –Zr 100− x ( x = 0, 10, 20, …, 100) based oxide composites were studied using conventional solid state sintering process in the temperature range 1400–1600 °C. Critical experimental parameters like green density, sintering time and temperature were varied to achieve higher sintered product. Systematic studies of densification, structural, microstructural, hardness and shrinkage properties were carried out to understand the real sintering process development mechanism involved in this oxide matrix during initial, intermediate and final stage of sintering. Interesting development in connection with microstructural and phase evolution, pore-grain network in relation to physical densification and hardness behaviour are analysed and it is noted that compositional variation in Al x –Zr 100− x oxide matrix ( x = 0, 10, 20, …, 100) produces structural (monoclinic to tetragonal) phase separation (complete or partial) at different sintering temperatures (1400–1600 °C). Long heating schedule (20 h) at high sintering temperature (1600 °C) promotes highest percentage of monoclinic–tetragonal transformation at x = 30 in Al x –Zr 100− x oxide composites.