Deformation behaviour of Zr-based metallic glass and metallic glass composite at elevated temperatures

在这个项目中，详细的纳米晶化的Zr 55 Cu 30 Ni 5 Al 10块体金属玻璃将使用TEM研究与部分纳米晶化的Zr 55 Cu 30 Ni 5 Al 10块体金属玻璃通过预先退火后的两种类型的样品在高应变速率和高温下变形后的比较。不同类型的样品的比较允许理解的nanocystization的高温变形行为和transitionfrom不均匀到均匀的流动关于新的nanocystized相和通过先前的退火获得的部分nanocystized相之间的反应的效果。此外，它是感兴趣的，以优化铸造条件的Zr 66.4 Cu 10.5 Ni 8.7 Al 8块体金属玻璃复合材料与韧性枝晶，以控制和建立一个不同的长度尺度和体积分数的枝晶，从而了解的形态和体积分数的影响，在不同的应变速率和在升高的温度下的ciscous流。最后，系统地研究和比较了单块体金属玻璃、部分纳米化块体金属玻璃和含延性相的块体金属玻璃复合材料在高温下的变形行为。这也将有助于理解非晶相、纳米晶和微米级枝晶之间剪切带的产生、运动和相互作用

In this project, the detailed nanocrytallization of the Zr55Cu30Ni5Al10 monolithic bulk metallic glass will be investigated using TEM in comparison with that of the partially nanocrystallized Zr55Cu30Ni5Al10 bulk metallic glass obtained by previous annealing after the deformation of both types of samples at high strain rates and at elevated temperatures. The comparison of the different types of samples allows to understand the effect of the nanocrystallization on the high temperature deformation behaviour and the transitionfrom inhomogeneous to homogeneous flow regarding the reaction between the newly nanocrystallized phase and the partially nanocrystallized phase obtained by previous annealing. In addition, it is of interest to optimize the casting conditions of the Zr66.4Cu10.5Ni8.7Al8 bulk metallic glass composite with ductile dendrites in order to control and establish a different lenght scale and volume fraction of dendrites, and hence to understand the effect of the morphology and the volume fraction of the dendrites, on the ciscous flow at various strain rates and at elevated temperatures. Finally, the deformation behavior at elevated temperatures between monolithic bulk metallic glass, partially nanocrystallized bulk metallic glass and bulk metallic glass composite with ductile phase will be systematically investigated and compared. This will be also helpful to understand the generation, movement and interaction of shear bands between the amorphous phase, the nanocrystals, and the micrometer- sized dendrites