静高压下Al-Mn准晶形成及其结构稳定性的研究

 静高压（4.5 GPa）下Al₆Mn合金熔态淬火（冷却速度约为10² ℃/s），得到Al₆Mn合金的高压淬火样品。X射线分析表明：Al₆Mn合金的高压淬火样品中含有准晶二十面体相、Al₆Mn相及Al的面心立方相；与常压结果相比，高压淬火方法的冷却速率可比常压的低约3个数量级的条件下产生准晶二十面体相。其晶化温度与急冷甩带的相近。对静高压（2.5 GPa）下Al₆Mn准晶条带样品的晶化过程进行了研究。X射线分析表明：静高压下Al₆Mn准晶条带样品的晶化过程中，出现了一种新的未知亚稳相——准晶向晶体转化中的一种中间过渡态，具有类T相形式；与常压结果比较，高压下准晶相晶化温度提高。

A STUDY ON THE FORMATION AND THE STABILITY OF Al6Mn QUASICRYSTAL UNDER HIGH STATIC PRESSURE

In this paper, a new method of quenching at fuse state (1 300 ℃) under high static pressure (4.5 GPa) hase been set up to prepare the quasicrystal icosahedral phase of the Al₆Mn alloy, the crystallization temperature of which is close to the one of rapid cooling ribbon sample, and the cooling rate during the quenching is of about 10² ℃/s. A new intermediate metastable phase (a T-phase-like) occures during the crystallization process of Ⅰ-phase under high static pressure (2.5 GPa) for the rapid cooling ribbon of Al₆Mn. The high static pressure increases its crystallization temperature and enhances the stability of the intermediate metastable phase.