Cu-Zr-Al-Nb块体金属玻璃的非晶形成能力和力学性能（英文）

Glass Forming Ability and Mechanical Properties of Cu-ZrAl-Nb Amorphous Alloy

采用悬浮熔炼-水冷铜模吸铸法制备不同直径的Cu46Zr44Al5Nb5非晶合金,并研究其非晶形成能力和力学性能。XRD分析、DSC曲线和透射电镜的选区电子衍射花样结果表明,直径分别为3,4,6 mm的合金棒均为全非晶结构,该合金成分具有良好的玻璃形成能力和热稳定性,其过冷液相区宽度和约化玻璃转变温度分别为52 K和0.60。由TTT曲线计算得出合金的玻璃形成临界冷却速率为3.985 K/s。不同尺寸合金棒凝固过程中的冷却速率不同,导致制得不同直径合金棒的X衍射峰强度、晶化焓和断裂强度呈现显著差异。

Cu46Zr44A15Nb5 amorphous alloys were fabricated by suspend melting under an argon atmosphere using water-cooled Cu mould suction casting. Glass forming ability and mechanical properties of the alloys were studied. The analyses of DSC curves, X-ray diffraction （XRD） patterns and electron diffraction taken from the rods of Cu46Zr44A15Nb5 with different diameters （3, 4, 6 mm） indicate that the critical diameter can be up to 6 mm at least. And the best glass former exhibits an undercooled liquid region AT of 52 K, and reduced glass transition temperature Trg of 0.60. The critical cooling rate （Re） calculated from TTT （Time-Temperature-Transformation） curves of Cu46Zr44A15Nb5 forming glassy alloy is 3.985 K/s. The intensity of broad peaks from X-ray diffraction patterns, the crystallization enthalpy and the fracture strength of the amorphous rods with different diameters, exhibit obvious difference, which is related to the variation of the cooling rate of solidification for the rods with different size.