论文部分内容阅读
采用悬浮熔炼-铜模吸铸法制备了Cu50Zr42Al8块体金属玻璃,研究了其楔形试样的组织演变。随着熔体凝固过程中冷却速度的变化,楔形试样中存在表面全非晶区,中心晶体区以及二者之间的过渡区域,并确定Cu50Zr42Al8块体金属玻璃临界尺寸为4.8mm。分别考察了4mm铸态完全非晶棒和5mm非晶复合棒的力学性能。4mm非晶棒的压缩断裂强度,弹性应变和塑性应变分别为2260MPa,2.0%,0.4%,几乎没有塑性变形。而5mm铸态非晶复合棒的屈服强度、断裂强度分别为1670MPa、1849MPa,弹性应变和塑性应变分别为1.6%和1.9%。非晶基体中存在的马氏体相CuZr和正交晶相Cu10Zr7的竞争影响了非晶复合棒的最终力学行为。
The Cu50Zr42Al8 bulk metallic glass was prepared by suspension melting and copper mold suction casting. The microstructure evolution of the wedge-shaped specimen was studied. With the change of cooling rate in the process of melt solidification, the surface all-amorphous region, the central crystal region and the transition region between the two exist in the wedge-shaped sample, and the critical size of the Cu50Zr42Al8 bulk metallic glass is determined to be 4.8 mm. The mechanical properties of 4mm as-cast amorphous rods and 5mm amorphous composite rods were investigated respectively. The compressive rupture strength, elastic strain and plastic strain of 4mm amorphous rod are respectively 2260MPa, 2.0% and 0.4%, with almost no plastic deformation. The yield strength and fracture strength of 5mm as-cast amorphous composite rods were 1670MPa and 1849MPa respectively, and the elastic and plastic strains were 1.6% and 1.9% respectively. The competition between the martensite phase CuZr and the orthorhombic phase Cu10Zr7 in the amorphous matrix affects the final mechanical behavior of the amorphous composite rod.