Onawale Omoyemi Temitope, Cobbinah Prince Valentine, Nzeukou Rivel Armil, Matizamhuka Wallace Rwisayi
Department of Metallurgical Engineering, Vaal University of Technology, Andries Potgieter Boulevard, Vanderbijlpark 1911, South Africa.
Materials (Basel). 2021 Jun 4;14(11):3065. doi: 10.3390/ma14113065.
Microstructural phase evolution during melting and casting depends on the rate of cooling, the collective mobility of constituent elements, and binary constituent pairs. Parameters used in mechanical alloying and spark plasma sintering, the initial structure of binary alloy pairs, are some of the factors that influence phase evolution in powder-metallurgy-produced HEAs. Factors such as powder flowability, laser power, powder thickness and shape, scan spacing, and volumetric energy density (VED) all play important roles in determining the resulting microstructure in additive manufacturing technology. Large lattice distortion could hinder dislocation motion in HEAs, and this could influence the microstructure, especially at high temperatures, leading to improved mechanical properties in some HEAs. Mechanical properties of some HEAs can be influenced through solid solution hardening, precipitation hardening, grain boundary strengthening, and dislocation hardening. Despite the HEA system showing reliable potential engineering properties if commercialized, there is a need to examine the effects that processing routes have on the microstructure in relation to mechanical properties. This review discusses these effects as well as other factors involved.
熔化和铸造过程中的微观结构相演变取决于冷却速率、组成元素的集体迁移率以及二元组成对。机械合金化和放电等离子烧结中使用的参数，即二元合金对的初始结构，是影响粉末冶金制备的高熵合金中相演变的一些因素。诸如粉末流动性、激光功率、粉末厚度和形状、扫描间距以及体积能量密度（VED）等因素在增材制造技术中确定最终微观结构方面都起着重要作用。大的晶格畸变会阻碍高熵合金中的位错运动，这可能会影响微观结构，尤其是在高温下，从而导致一些高熵合金的力学性能得到改善。一些高熵合金的力学性能可通过固溶强化、沉淀强化、晶界强化和位错强化来影响。尽管如果商业化，高熵合金体系显示出可靠的潜在工程性能，但仍有必要研究加工路线对与力学性能相关的微观结构的影响。本综述讨论了这些影响以及其他相关因素。
