论文部分内容阅读
利用X射线衍射仪(XRD)、光学显微镜、万能试验机和扫描电镜(SEM)等仪器研究在不同热处理温度下的Zr_(48)Co_(52)合金的微观组织和力学性能。结果表明,合金在723 K和773 K温度下进行热处理后的相组成和铸态合金相组成相同,主要相仍为简单立方结构的B2相,在基体B2相上析出少量的B33相。另外,铸态合金和在热处理温度为723 K和773 K时,合金的微观组织形貌呈现“麦穗”状、长条状和颗粒状等轴晶,且等轴晶尺寸为2~4μm。在热处理温度为773 K,合金的最大抗压强度为848 MPa,而断裂强度为825 MPa,维氏硬度为396 HV。在对断口进行分析,发现以铸态合金延性断裂为主的断裂机制转变为在723 K和773 K下进行热处理的以沿晶断裂和解理断裂为主,延性断裂为辅的断裂机制。
The microstructure and mechanical properties of Zr_ (48) Co_ (52) alloy under different heat treatment temperatures were investigated by X-ray diffraction (XRD), optical microscope, universal testing machine and scanning electron microscope (SEM) The results show that the phase composition of the alloy after heat treatment at 723 K and 773 K is the same as that of the as-cast alloy. The main phase is still the B2 phase with simple cubic structure, and a small amount of B33 phase precipitates on the B2 phase of the matrix. In addition, the microstructures of as-cast alloys and alloys with the heat treatment temperature of 723 K and 773 K show the shape of “wheat”, elongated and granular equiaxed grains with equiaxed grains of 2 ~ 4μm. At a heat treatment temperature of 773 K, the maximum compressive strength of the alloy is 848 MPa, while the rupture strength is 825 MPa and the Vickers hardness is 396 HV. Based on the analysis of the fracture, it is found that the fracture mechanism dominated by as-cast ductile fracture transforms into the fracture mechanism dominated by intergranular fracture and cleavage fracture, supplemented by ductile fracture at 723 K and 773 K.