烧结温度对AlTiVZr0.2B0.2高熵合金组织和性能的影响

采用真空热压烧结工艺,在不同的烧结温度下制备了AlTiVZr0.2B0.2高熵合金,对合金的微观组织和力学性能进行了研究。结果表明,AlTiVZr0.2B0.2高熵合金主要由简单立方结构的基体相和大量球状的黑色TiB12与白色Al3Zr2析出相组成,其密度低于目前常用的TC4钛合金,而硬度和压缩强度均高于TC4钛合金。1 100℃制备的高熵合金具有最高的硬度(809.7HV)、抗压强度(2 080MPa)和比强度(432.7×10^3 N·m/kg)。原因在于1 100℃烧结时,组织中的TiB12与白色Al3Zr2析出相弥散度最高,分布最均匀,具有最好的弥散强化效果。

Effects of Sintering Temperature on Structure and Mechanical Properties of AlTiVZr0.2B0.2 High Entropy Alloy

AlTiVZr0.2B0.2 high entropy alloys were prepared by vacuum hot pressing sintering process at varied sintering temperatures.The microstructure and mechanical properties of the alloy prepared were investigated.The results show that AlTiVZr0.2B0.2 high entropy alloy mainly consists of the matrix phase with simple cubic structure and spherical precipitates of black TiB12 and white Al3Zr2.The densities of the alloys are lower than that of TC4 titanium alloy while the hardness and compressive strength are higher than that of one.Especially,the AlTiVZr0.2B0.2 alloy prepared at 1 100℃presents the highest hardness(809.7 HV),compressive strength(2 080 MPa)and specific strength(432.7×10^3 N·m/kg),which is attributed to the precipitation of TiB12 and white Al3Zr2 in the microstructure of the alloys sintered at 1 100℃with the highest dispersion degree and the most uniform distribution,so showing the desirable dispersion strengthening effect.