(中国科学院金属研究所,沈阳 110016)
摘 要: 采用原位热等静压法制备Ti2AlN/Al2O3复合材料,利用SEM和TEM研究Ti2AlN/Al2O3材料的微观结构及第二相颗粒Al2O3对复合材料的线性膨胀系数、热导率和硬度的影响。结果表明:Ti2AlN/Al2O3复合材料由片层状块体Ti2AlN相和弥散分布在基体内的近球形Al2O3颗粒组成。Ti2AlN/Al2O3复合材料的平均线性膨胀系数为9.86×10-6 ℃-1,热扩散率随着温度的升高而降低,比热容随着温度的升高而缓慢地增大,热导率随温度的升高而线性下降。Ti2AlN/Al2O3复合材料的强化机制主要为第二相粒子强化,Al2O3颗粒可以明显提高复合材料的硬度。室温下复合材料的维氏硬度为9 GPa,是单相Ti2AlN硬度的2.25倍。
关键字: Ti2AlN/Al2O3;复合材料;热等静压
(Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)
Abstract:The microstructure of Ti2AlN/Al2O3 composite fabricated by in-situ hot isostatic pressing was investigated by SEM and TEM and influence of Al2O3 particles on linear expansion coefficient, thermal conductivity and hardness of Ti2AlN/Al2O3 composite. The results show that the matrix Ti2AlN phase grains are plate-like, the strengthen Al2O3 particles are near spherical and disperse in matrix homogeneously. The average linear expansion coefficient of Ti2AlN/Al2O3 composite is 9.86×10-6 ℃-1. Thermal diffusivity decreases with the increase of the temperature, the specific heat capacity increases slowly with the increase of the temperature. The thermal conductivity of Ti2AlN/Al2O3 composite material decreases linearly with the increase of the temperature. The strengthening mechanism of composite is the second phase strengthen. Al2O3 particles can significantly improve the hardness of the composite. The Vickers hardness of Ti2AlN/Al2O3 is 9 GPa and 2.25 times as that of Ti2AlN at room temperature.
Key words: Ti2AlN/Al2O3; composite; hot isostatic pressing