ABSTRACT

A new experimental setup to continuously and automatically measure ultrasonic elastic wave velocities, X-ray radiography, and X-ray diffraction in large volume press is developed to explore structural change of amorphous materials at in situ high pressure and high temperature conditions. A continuous measurement for Zr₅₀Cu₄₀Al₁₀ metallic glass is carried out during the heating process from 304 to 1102 K under high pressure conditions of 6.8–8.6 GPa. The sample length, elastic wave velocities, and Poisson’s ratio show marked changes at 611, 745, 825, and 874 K, which are interpreted as glass transition temperature (T_g) at 611 K, two polyamorphic structural changes at 745 and 825 K, and crystallization above 874 K, respectively. We find that the 1.2T_g temperature (733 K at ∼8 GPa), where simulations study predicted occurrence of thermal rejuvenation, corresponds to the temperature of the polyamorphic structural change (745 K) in Zr₅₀Cu₄₀Al₁₀ metallic glass.

摘要

开发了一种新的实验装置，可在大体积压力机中连续自动测量超声弹性波速度、X 射线照相和 X 射线衍射，以探索原位高压和高温条件下非晶材料的结构变化。Zr ₅₀ Cu ₄₀ Al ₁₀金属玻璃的连续测量是在 6.8-8.6 GPa 的高压条件下从 304 到 1102 K 的加热过程中进行的。样品长度、弹性波速度和泊松比在 611、745、825 和 874 K 处显示出显着变化，这被解释为玻璃化转变温度 ( T _g) 在 611 K，分别在 745 和 825 K 处发生两种多晶结构变化，并分别在 874 K 以上结晶。我们发现 1.2T _g温度（~8 GPa 时为 733 K），其中模拟研究预测了热再生的发生，对应于 Zr ₅₀ Cu ₄₀ Al ₁₀金属玻璃中_多晶结构变化的温度（745 K）。