A novel ceramic derived processing route for Multi-Principal Element Alloys
A novel ceramic derived processing route for Multi-Principal Element Alloys
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DOI：
10.1016/j.msea.2020.139892
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发表时间：
2020-07
期刊：
影响因子：
6.4
通讯作者：
M. Gianelle;A. Kundu;K. P. Anderson;A. Roy;G. Balasubramanian;H. M. Chan
中科院分区：
文献类型：
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作者：
M. Gianelle;A. Kundu;K. P. Anderson;A. Roy;G. Balasubramanian;H. M. Chan
近年来，多主元素合金（MPEAs）已经成为一种新的和令人兴奋的材料。迄今为止，MPEAs最广泛使用的加工方法是电弧熔炼和机械合金化。该研究探讨了一种替代的，新的工艺来处理散装MPEA样品，即氧化物粉末前体混合物的还原的可行性。选择等原子CuCoFeNi作为研究的模型系统，因为这些元素形成已经研究的大比例MPEA组合物的子集。采用标准陶瓷加工方法对Co 3 O 4、CuO、Fe 2 O3和NiO的高纯度前体氧化物粉末进行研磨和混合。将绿色球团在1000 °C下在流动的5%H2-N2中进行还原退火处理，热处理时间为4至1000 h。4小时后，样品转化为无残留氧化物的致密金属块状样品。用X射线能谱仪、扫描电镜和X射线衍射仪对合金的微观结构进行了表征，结果表明合金由多晶基体和位于三相点处的富铜第二相组成。用纳米压痕法研究了其硬度。使用EPMA（电子探针分析），确定基质的组成为Cu18.1Co26.6Fe26.9Ni28.4（at%），其代表单相MPEA组成。氧化物还原是一种可行的技术，用于处理块体复杂的金属合金，具有新的微观结构定制的潜力。
In recent years, Multi-Principal Element Alloys (MPEAs) have emerged as a new and exciting class of materials. To date, the most widely used processing methods for MPEAs are arc melting and mechanical alloying. The study explores the feasibility of an alternative, novel process to process bulk MPEA samples, namely the reduction of an oxide powder precursor mix. Equiatomic CuCoFeNi was selected as a model system of study because these elements form a subset of a large proportion of MPEA compositions already studied. High purity precursor oxide powders of Co3O4, CuO, Fe2O3and NiO were milled and mixed using standard ceramic processing methods. The green pellets were subjected to a reduction annealing treatment in flowing 5%H2–N2at 1000 °C, with heat-treatment times ranging from 4 to 1000 h. After 4 h, the sample was transformed into a dense metallic bulk sample with no residual oxides. The microstructure was characterized by x-ray EDS, SEM and XRD, and was shown to consist of a polycrystalline matrix, and a copper-rich second phase situated at the triple points. The hardness was studied by nano-indentation. Using EPMA (electron microprobe analysis), the composition of the matrix was determined to be Cu18.1Co26.6Fe26.9Ni28.4(at%), which represents the single phase MPEA composition. Oxide reduction is a viable technique for processing bulk complex metallic alloys, with potential for novel microstructural tailoring.