High-temperature Mechanical Properties of Al_2O_3/Ti_3SiC_2 Multilayer Ceramics

摘要

The high-temperature mechanical properties were very important to structural materials, especially structural ceramics. Hence, the strength, elastic modulus, stress relaxation and creep behavior of the multilayer materials at elevated temperature were studied in this paper. According to the curves of mechanical properties varieties with temperature risen from room-temperature to 1300°C, the multilayer materials could remain relatively high mechanical properties until 1150°C. Otherwise, the creep function of the multilayer composites was also determined, in which the stress exponent was 1.4 and activation energy was 204kJ/mol. By contrasting to the monolithic ceramics of Al_2O_3 and Ti_3SiC_2, the main creep mechanisms include: interface diffusion creep (in Al_2O_3 layers), dislocation movement creep, grain delamination and sliding (in Ti_3SiC_2 layers).