Mechanical Properties and Microstructure of SiC-ZrO2(3Y)-Al2O3 Nanocomposites
SiC-ZrO2(3Y)-Al2O3纳米复相陶瓷的力学性能和显微结构

Heterogeneous precipitation methods were used to produce 5wt% SiC-15wt% ZrO2 (3Y)-Al2O3nanocomposite powders. The aqueous suspension's pH controlled between 9 and 10, and the resulting gel calcined at 1000 are two key processes for preparing nanocomposite powders. 5wt%SiC--15 wt% Zro2(3Y)-Al2O3 nanocomposites were superfast densified using spark plasma sintering (SPS) process by heating to a sintering temperature between 1350 to 1600 at a heating rateof 600/min, without holding time, and then fast cooling to 600 within 3 minutes. Bendingstrength of 5wt% SiC-15wt% ZrO2(3Y)--Al2O3 nanocomposites sintered at 1450 reached a valueas high As 1200MPa, while the fracture toughness of the sample sintered at 1450 was aboveSMPa.m1/2, which is significantly higher than that of SiC-Al2O3 nanocomposites and Al2O3 ceramics. Microstructure studies found that nano-SiC particles were mainly located within Al2O3grains and the fracture mode of the nanocomposites was mainly transgranular fracture. It is themain reason why the intra-type nanocomposites show excellent mechanical properties, while inpresent research system, a part of contribution to high mechanical properties is from ZrO2 phasetransformation toughening.