退火处理对Ti-Zr-Cu-Be块体非晶合金力学性能的影响

采用铜模铸造法制备了直径为2mm的Ti55-xZr10+xBe27.5Cu7.5(x=0,10,20)块体非晶合金,并对其进行等温退火处理.利用X射线衍射(XRD)、扫描电镜(SEM)、差氏扫描量热仪(DSC)及压缩试验等方法研究了非晶合金的相结构、显微组织和热稳定性,以及退火处理对其力学性能的影响.结果表明:该系列合金在553 K及583 K下保温长达5 h时间内依然表现为非晶态.退火处理后,Ti35Zr30Be27.5Cu7.5合金屈服强度、断裂强度均提到了提高,其中在583 K下保温1 h后屈服强度、断裂强度分别达到了1 921、2 169 MPa;其塑性由处理前的3.47%提高到了6.57%.Ti45Zr20Be27.5Cu7.5合金在退火后其力学性能变化不明显.Ti55Zr10Be27.5Cu7.5合金随着退火温度及保温时间的增加其屈服强度、断裂强度及塑性均明显降低.

Effect of isothermal annealing treatment on mechanical properties of Ti-Zr-Cu-Be bulk amorphous alloys

Bulk amorphous alloys of Ti55-xZr10+xBe27.5Cu7.5(x=0,10,20) with diameter of 2 mm were obtained by copper mould casting,and then isothermal annealing treatment at different temperatures was carried out.The phase structure,microstructure,thermal stability,especially the effects of isothermal annealing treatment on the compression strength and plasticity of these bulk amorphous alloys were investigated by means of X-ray diffraction(XRD),scanning electron microscopy(SEM),differential scanning calorimetry(DSC) and compression tests.The results show that these bulk alloys are still retained by amorphous phase at 553 K and 583 K for 5 h respectively.High yield strength of 1 921 MPa,high compression strength of 2 169 MPa and distinct plastic strain of 6.57% were obtained in the Ti35Zr30Be27.5Cu7.5 bulk amorphous alloy annealed at 583 K for 1 h.No distinct change of mechanical properties for Ti45Zr20Be27.5Cu7.5 amorphous alloy can be detected after annealing.However,yield strength,breaking strength and plastic strain of the Ti55Zr10Be27.5Cu7.5 amorphous alloy are decreased remarkably with increasing of the annealing time and temperature.