基于铝热反应多主元合金的成分调控研究

近年来，多主元高熵合金由于其组织、结构和性能可调性受到了广泛的研究，目前高熵合金常用的制备方法有熔炼法和粉末冶金法，而本文基于一种快速高效的高熵合金制备方法-铝热法，对多主元合金的成分调控进行研究。采用Fe3O4、Co3O4、Ni2O3、CrO3和MnO2五种氧化物经铝热反应后获得10种二元合金、10种三元合金、5种4元合金和1种5元合金，利用SEM、EDS等表征技术对多主元合金进行显微组织观察与元素分析，探究了多种不同氧化物铝热反应的负焓值与铝热还原产物成分之间的对应关系，进而推广到多种氧化物铝热反应的负焓值与反应后成分之间的一般规律，并提出对应的函数关系式，并基于此制备了近似等摩尔比的CoCrFeNiMnAl高熵合金，从而实现对铝热法制备多主元高熵合金的成分的调控。并对CoCrFeNiMnAl高熵合金的性能进行研究，该合金硬度为508.1 HV0.5，摩擦系数和磨损率分别为0.73和4.78×10-5 mm3/N·m，在3.5 wt.%NaCl溶液中的腐蚀电流密度和腐蚀电位分别为1.097×10-6 A·cm?2和-0.347 V。

Study on composition control of multi-principal component alloys based on thermal reaction

In recent years, multi-principal element high-entropy alloys have been extensively studied due to its microstructure and performance tunability. At present, the commonly used preparation methods of high-entropy alloys are smelting and powder metallurgy. This article is based on a efficient preparation method of high-entropy alloy-thermite method, and to study the composition control of multi-principal alloys. Five oxides of Fe3O4, Co3O4, Ni2O3, CrO3 and MnO2, were used to obtain 10 binary alloys, 10 ternary alloys, 5 quaternary alloys and 1 quinary alloy by thermite reaction. Microstructure observation and element analysis of multi-principal element alloys were carried out by SEM, EDS, and the corresponding relationship between the negative enthalpy of the thermite reaction of a variety of different oxides and the composition of the thermite reduction products was investigated. The general law between the negative enthalpy value of various oxides of aluminum thermal reaction and the composition after reaction is extended, and the corresponding functional relations are put forward. Based on this, a CoCrFeNiMnAl high-entropy alloy with approximately equimolar ratio was prepared, so as to realize the control of the composition of multi-principal element high entropy alloy prepared by aluminothermic method. And the performance of CoCrFeNiMnAl high-entropy alloy was studied, the hardness of the alloy was 508.1 HV0.5, the friction coefficient and wear rate were 0.73 and 4.78×10-5 mm3/N·m, respectively. The corrosion current density and corrosion potential of the alloy in 3.5 wt.%NaCl solution were1.097×10-6 A·cm?2 and -0.347 V, respectively.