Autowave synthesis of cast oxide ceramics Al2O3–Cr2O3 · ZrO2

Resumo

The regularities for the autowave synthesis (SHS) of a cast oxide composite material (Al₂O₃–Cr₂O₃ · ZrO₂) were studied by example of combustion of thermite-type systems under an inert gas pressure. The ratio of starting reagents with optimal zirconia content was determined for the synthesis of the desired product on the basis of analysis of published data and thermodynamic calculations (Thermo program). In the experiments, it was shown that combustion temperature and sample mass are the most important parameters influencing the composition and microstructure of the final product. Optimal conditions for the process control were defined. The final product includes solid solution Al₂O₃–Cr₂O₃ grains located on the boundaries of ZrO₂ particles. The material is promising for production of machine parts working in conditions of intense wear and shock loads in corrosive environments at elevated temperatures (for example, sintering of ceramic cutting tools).