Preparation of spherical TaNbHfZrTi high-entropy alloy powders by a hydrogenation-dehydrogenation reaction and thermal plasma treatment
Preparation of spherical TaNbHfZrTi high-entropy alloy powders by a hydrogenation-dehydrogenation reaction and thermal plasma treatment
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DOI：
10.1016/j.jallcom.2019.152757
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发表时间：
2020-03-15
影响因子：
6.2
通讯作者：
Park, Hyung-Ki
中科院分区：
文献类型：
--
作者：
Na, Tae-Wook;Park, Ki Beom;Park, Hyung-Ki
采用氢化-脱氢反应和热等离子体处理相结合的方法制备了球形TaNbHfZrTi高熵合金粉末。HEA锭具有单一的固溶体体心立方（BCC）相，并且在氢化之后其完全转变为M3 H2的金属氢化物相。氢化锭由于其脆性性质而可以容易地粉碎成细粉末，并且粉末颗粒具有高度不规则的形状。脱氢后，粉末的相分离为三相：两个BCC相（BCC 1，BCC 2）和一个六方密堆积（HCP）相。根据HEA氢化物的分解行为的结果，在不同温度下释放出不同量的氢。氢排放显示出两个峰值，最高值在331.9和721.7 ℃，这与相分离有关。采用感应耦合热等离子体对脱氢后的不规则粉末进行球化处理。经等离子体处理后，HEA粉末具有单一的固溶体BCC相，其形貌变为球形。因此，利用该方法可以成功地制备出球形的TaNbHfZrTi HEA粉末。(C)2019爱思唯尔B. V.保留所有权利。
Spherical TaNbHfZrTi high-entropy alloy (HEA) powders were fabricated successfully by a hydrogenation -dehydrogenation reaction and thermal plasma treatment. The HEA ingot had a single solid solution body-centered cubic (BCC) phase, and it was fully transformed to a metal hydride phase of M3H2 after hydrogenation. The hydrogenated ingot could be easily pulverized to fine powders because of its brittle nature, and the powder particles had highly irregular shapes. After dehydrogenation, the phase of the powders was separated to three phases: two BCC phases (BCC 1, BCC 2) and one hexagonal-close-packed (HCP) phase. Based on the results of the decomposition behavior of the HEA hydride, hydrogen was released in various amounts at different temperatures. Hydrogen emissions showed two peaks, the highest at 331.9 and 721.7 degrees C, which were related to the phase separation. The dehydrogenated powders with the irregular shapes were spheroidized by an inductively coupled thermal plasma treatment. After the plasma treatment, the HEA powders had a single solid solution BCC phase and their morphology changed to a spherical shape. Thus, with this method, spherical TaNbHfZrTi HEA powders could be fabricated successfully. (C) 2019 Elsevier B.V. All rights reserved.