Properties of atomized AlCoCrFeNi high-entropy alloy powders and their phase-adjustable coatings prepared via plasma spray process
Properties of atomized AlCoCrFeNi high-entropy alloy powders and their phase-adjustable coatings prepared via plasma spray process
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DOI：
10.1016/j.apsusc.2019.01.203
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发表时间：
2019-06-01
影响因子：
6.7
通讯作者：
Chen, Shih-Hsun
中科院分区：
文献类型：
--
作者：
Cheng, Kuei-Chung;Chen, Jing-Han;Chen, Shih-Hsun
在本研究中，采用真空气体雾化粉末等离子喷涂工艺实现了高熵合金（HEA）涂层相组成的调整。制备的AlCoCrFeNi粉末为纯BCC相，颗粒呈球形。FCC相在600℃以上开始形成，其结晶度随着退火温度的升高而增大，导致饱和磁化强度降低。在雾化粉末中观察到两种居里温度：第一种温度约为220摄氏度，是可逆的；其次是在600℃以上发生不可逆的FCC相变。等离子喷涂工艺沉积AlCoCrFeNi涂层时，随着喷涂电流的增大和氩气流量的增大，FCC相的比例增大。然而，粉末粒度对涂层的相组成也有影响。对于粗粉（60 ~ 90 μ m），即使电流和气体流量分别增加到750 A和50 l/min，也能抑制FCC相的形成。等离子喷涂铝铬feni的孔隙度、硬度和饱和磁化强度等物理性能可以通过调整其相组成来调节。
In this study, the adjustment of the phase constitution of AlCoCrFeNi high-entropy alloy (HEA) coatings was achieved using a plasma spray process with vacuum gas-atomized powders. The as-prepared AlCoCrFeNi powders were of pure BCC phase and the particles were in spherical shape. The FCC phase began to form above 600 degrees C, and its degree of crystallinity increased with annealing temperature, resulting in a reduced saturation magnetization. Two Curie temperatures were observed in as-atomized powders: the first was around 220 degrees C and was reversible; the second was contributed by the irreversible FCC phase transformation over 600 degrees C. When depositing the AlCoCrFeNi coating using the plasma spray process, the ratio of the FCC phase increased with increasing spraying current and argon flow rate. However, the phase constitution of the AlCoCrFeNi coatings was also influenced by powder size. With coarse powders (60-90 mu m), the formation of FCC phase was suppressed, even as the current and gas flow were increased to 750 A and 50 l/min, respectively. The physical properties, such as porosity, hardness, and saturated magnetization, of plasma-sprayed AlCoCrFeNi can hence be adjusted by tuning its phase constitution.