Y2O3含量对钼合金组织和性能的影响

采用粉末冶金方法制备含Y2O3的稀土钼合金,利用金相显微镜、扫描电子显微镜(SEM)、X射线衍射(XRD)、能谱分析(EDS)等手段对钼合金的断裂特征和组织结构进行对比分析,研究稀土氧化物Y2O3含量对钼合金组织和性能的影响.研究表明:添加Y2O3能细化晶粒、改善钼合金的晶粒均匀性和致密度、提高钼合金的性能:拉伸强度和屈服强度随Y2O3含量的增加呈现先增高后降低的趋势,在Y2O3含量为1％时,抗拉强度达511.43MPa,屈服强度456.99MPa,分别是纯钼材料的1.31倍和1.57倍,综合力学性能最佳；在烧结坯中,Y2O3颗粒分布均匀,主要以球形和等轴状形式存在于晶界上.

Effect of Y2O3 content on microstructure and properties of molybdenum alloys

The effects of Y2O3 content on microstructure and mechanical properties of molybdenum alloys were studied.Mo-Y alloys with different Y2O3 contents were prepared by powder metallurgy(P/M) method.Mo-Y alloys fracture characteristic and microstructure were characterized by metallographic microscope,SEM,XRD and EDS,respectively.The results show that the performances of the alloys improved by adding Y2O3 due to the grain size can be refined and become uniform and the density of alloy can be improved through adding Y2O3.With increasing Y2O3 content,tensile strength and yield strength of alloys increase firstly and then decrease.When Y2O3 content is 1%,tensile strength and yield strength are 511.43 MPa and 456.99 MPa,which are 1.31 times and 1.57 times of pure Mo alloy,respectively,and the optimum mechanical poperties of Mo-Y alloys are obtained.The Y2O3 particles with sphericity and isometric shape distribute homogeneoully on the molybdenum grain boundaries of the sintered alloys.