本文介绍用非均相沉淀方法制备的纳米ＳｉＣ－ＺｒＯ２（３Ｙ）－Ａｌ２Ｏ３复合粉体经放电等离子超快速烧结得到晶肉型的纳米复相陶瓷；超快速烧结的升温速率为６００／ｍｉｎ；在烧结温度不保温，迅即在３ｍｉｎ内冷却至６００以下．力学性能研究结果表明，在１４５０超快速烧结得到的纳米复相陶瓷的抗弯强度高达１２００ＭＰａ，断裂韧性Ｋ１ｃ为５ＭＰａ·ｍ１／２ＴＥＭ像显示纳米ＳｉＣ颗粒大多分布在Ａｌ２Ｏ３母体晶粒内，也有一些纳米ＳｉＣ颗粒分布在ＺｒＯ２晶粒内．断裂表面的ＳＥＭ像表明，穿晶断裂是其主要的断裂模式，这是所制备的纳米复相陶瓷力学性能大幅提高的主要原因．
Heterogeneous precipitation methods were used to produce 5wt% SiC-15wt% ZrO2(3Y)-Al2O3 nanocomposite 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 rate of 600℃/min, without holding time, and then fast cooling to 600℃ within 3 minutes. Bending strength of 5wt% SiC-15wt%
ZrO2(3Y)-Al2O3 nanocomposites sintered at 1450℃ reached a value as high as 1200MPa, while the fracture toughness of the sample
sintered at 1450℃ was above 5MPa·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 Al2O3 grains and the fracture mode of the nanocomposites was mainly transgranular fracture. It is the main reason
why the intra-type nanocomposites show excellent mechanical properties, while in present research system, a part of contribution to high mechanical
properties is from ZrO2 phase transformation toughening.
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