摘要
The Mo alloys reinforced by Al2O3 particles were fabricated by hydrothermal synthesis and powder metallurgy. The microstructures of Mo-Al2O3 alloys were studied by using XRD, SEM and TEM. The results show that Al2O3 particles, existing as a stable hexagonal phase(α-Al2O3), are uniformly dispersed in Mo matrix. The ultrafine α-Al2O3 particles remarkably refine grain size and increase dislocation density of Mo alloys. Moreover, a good interfacial bonding zone between α-Al2O3 and Mo grain is obtained. The crystallographic orientations of the interface of the Al2O3 particles and Mo matrix are [111]a-Al2O3//[111]Mo and(112)a-Al2O3//(0 11)Mo. Due to the effect of secondary phase and dislocation strengthening, the yield strength of Mo-2.0 vol.%Al2O3 alloy annealed at 1200 ℃ is approximately 56.0% higher than that of pure Mo. The results confirm that the addition of Al2O3 particles is a promising method to improve the mechanical properties of Mo alloys.
采用水热合成法和粉末冶金方法制备Al2O3颗粒增强Mo合金,并利用XRD、SEM和TEM对所制备的Mo-Al2O3合金的显微组织进行研究。结果表明,Al2O3颗粒以稳定的六方相(α-Al2O3)形式均匀地分布在Mo基体中,超细α-Al2O3颗粒显著细化Mo合金的晶粒尺寸,增加Mo合金位错密度。此外,α-Al2O3与Mo晶粒间存在良好的界面结合区,且Al2O3颗粒与Mo基体界面存在一定的晶体学关系:[111]a-Al2O3//[111]Mo和(112)a-Al2O3//[111]Mo。由于二次强化效应和位错强化效应,与纯 Mo相比,1200℃退火Mo-2.0%Al2O3(体积分数)合金的屈服强度提高约56.0%。结果表明,添加Al2O3颗粒是改善Mo合金力学性能的一种有效方法。
基金
Projects(U1704152,U1804124)supported by the National Natural Science Foundation of China
Project(174100510012)supported by Plan for Scientific Innovation Talent of Henan Province,China。
