Uniaxial pulling and nano-scratching of a newly synthesized high entropy alloy
Uniaxial pulling and nano-scratching of a newly synthesized high entropy alloy
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DOI：
10.1063/5.0128135
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发表时间：
2022-11
期刊：
影响因子：
6.1
通讯作者：
Pengfei Fan;N. K. Katiyar;Xiaowang W. Zhou;S. Goel
中科院分区：
文献类型：
--
作者：
Pengfei Fan;N. K. Katiyar;Xiaowang W. Zhou;S. Goel
具有纳米晶结构的多组分合金，通常被称为Cantor合金或高熵合金（HEAs），继续吸引研究界的极大关注。已经提出，周期表中的大约64种元素可以以各种成分混合，以合成多达108种不同类型的HEA合金。HEAs的纳米力学结合实验和原子模拟在文献中是相当稀缺的，这是这项工作背后的主要动机。在这种精神下，一种新型的高熵合金（Ni25Cu18.75Fe25Co25Al6.25）的合成使用电弧熔炼方法，这遵循了联合模拟和实验的努力，调查位错介导的塑性机制，导致侧流，堆积，和晶体缺陷形成在次表面的HEA的过程中和之后的划痕过程。与HEA晶体面心立方结构塑性变形相关的主要晶体缺陷类型为2，3，4-hcp层状结构，如缺陷配位结构、共格∑3孪晶界和∑11断层或倾斜晶界，以及Stair棒、Hirth锁、Frank偏晶和Lomer-Cottrell锁。此外，1/6肖克利，特别是更大的位错环，被认为是运输商的堆垛层错更深的基板比所施加的切割载荷的位置。在HEA变形过程中，（100）取向显示出动摩擦系数的最高值，但切削应力和切削温度最小，这表明该取向优于其他取向，以改善接触模式制造。
Multicomponent alloys possessing nanocrystalline structure, often alluded to as Cantor alloys or high entropy alloys (HEAs), continue to attract the great attention of the research community. It has been suggested that about 64 elements in the periodic table can be mixed in various compositions to synthesize as many as ∼108 different types of HEA alloys. Nanomechanics of HEAs combining experimental and atomic simulations are rather scarce in the literature, which was a major motivation behind this work. In this spirit, a novel high-entropy alloy (Ni25Cu18.75Fe25Co25Al6.25) was synthesized using the arc melting method, which followed a joint simulation and experimental effort to investigate dislocation-mediated plastic mechanisms leading to side flow, pileup, and crystal defects formed in the sub-surface of the HEA during and after the scratch process. The major types of crystal defects associated with the plastic deformation of the crystalline face-centered cubic structure of HEA were 2,3,4-hcp layered such as defect coordination structures, coherent ∑3 twin boundary, and ∑11 fault or tilt boundary, in combination with Stair rods, Hirth locks, Frank partials, and Lomer–Cottrell locks. Moreover, 1/6 Shockley, with exceptionally larger dislocation loops, was seen to be the transporter of stacking faults deeper into the substrate than the location of the applied cutting load. The (100) orientation showed the highest value for the kinetic coefficient of friction but the least amount of cutting stress and cutting temperature during HEA deformation, suggesting that this orientation is better than the other orientations for improved contact-mode manufacturing.