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以纯度均为99%(质量分数)的板状刚玉,α-Al2O3微粉、TiO2微粉及金属铝粉为原料,经机械复合法制样后在流动氮气下利用常压铝热还原原位反应烧结的方法制备了Al2O3-TiN复合陶瓷材料。分析了不同的TiN生成量、烧结温度对试样的力学性能及显微结构的影响。结果表明:生成的TiN含量在10wt%的试样经过1500℃保温3 h后复合材料体积膨胀率为3.27%,体积密度为2.85 g/cm3、显气孔率28.73%、抗折强度23.81 MPa。显微结构分析表明,无压烧结作用下,铝热还原氮化反应并未发生典型的烧结过程,烧结温度、TiN的自身性质、反应的强放热以及TiN和Al2O3线膨胀系数之间的差别严重影响了复合材料的烧结致密化。
The pure alumina, α-Al2O3 fine powder, TiO2 fine powder and aluminum powder with purity of 99% (mass fraction) were used as raw materials, Methods Al2O3-TiN composite ceramic materials were prepared. The effects of different amounts of TiN and sintering temperature on the mechanical properties and microstructure of the samples were analyzed. The results show that the volume expansion rate of the composite with volume fraction of 2.85 g / cm3, porosity of 28.73% and flexural strength of 23.81 MPa are obtained after the samples with TiN content of 10wt% are kept at 1500 ℃ for 3 h. Microstructure analysis shows that the typical sintering process, sintering temperature, self-nature of TiN, strong exothermic reaction, and the difference between the linear expansion coefficients of TiN and Al 2 O 3 did not occur under the action of pressureless sintering Seriously affecting the sintering of the densification of composites.