摘要:本文中采用真空熔炼方法制备CoCrFeNiCuxTi0.3（X=0.5、1、1.5）高熵合金，对其分别在550℃，650℃，750℃，850℃，950℃进行12小时时效处理及在750℃分别时效50小时，100小时，200小时，400小时。通过对试样打磨、抛光、腐蚀，在金相显微镜下观察其不同时效条件下金相组织的变化。同时利用X射线衍射仪（XRD）、维氏硬度计等工具分析其性能与晶体结构的变化。CoCrFeNi-CuxTi0.3高熵合金的微观组织结构主要为面心立方（FCC）结构，其微观组织为典型的枝晶状组织。在经过时效处理后主要微观组织依然主要为FCC结构，还出现了少量的μ相。合金中其他元素比例相对固定时，Cu元素添加量的变化对合金的性能有很大影响，随着Cu元素含量的添加，其组织中Cu偏聚现象增加，硬度降低。CoCrFeNiCu0.5Ti0.3合金的硬度在文中所涉及到的相同时效条件下硬度比CoCrFeNiCuTi0.3合金高50HV-60HV。CoCrFeNiCuTi系合金的最佳时效温度约为750℃，在750℃时效12小时所获得的硬度比650℃/12h时效及850℃/12h时效所获硬度约高50HV。

关键字：高熵合金时效时间时效温度硬度

Abstract:In this paper, CoCrFeNiCuxTi3.3 (X = 0.5,1,1.5) high entropy alloy  was prepared by vacuum melting method, and the mixture was aged at 550 ℃, 650  ℃, 750 ℃, 850  ℃, 950  ℃ for 12 hours and 750  ℃ for 50 hours. 100 hours, 200 hours, 400 hours of aging to strengthen the treatment. Through the grinding, polishing and etching of the samples, the changes of the microstructure under different aging conditions were observed under a metallographic microscope. At the same time, X-ray diffraction (XRD), Vickers hardness tester and other tools to analyze its performance and crystal structure changes. The microstructure of CoCrFeNiCuTi high-entropy alloy is a single-phase face-centered cubic (FCC) structure, and its microstructure is typical dendritic. After aging treatment, the main microstructure is still  mainly phase  for the FCC  structure.  At  the  same time some phase  for    μhas appeared. When the proportion of other elements in the alloy is relatively fixed, the amount of Cu added to the alloy has a great influence on the properties of the alloy. With the addition of Cu element, the Cu segregation in the microstructure increases and the performance decreases. The hardness of CoCrFeNiCu0.5Ti0.3 alloy is 50HV-60HV higher than that of CoCrFeNiCuTi0.3 alloy under the same aging conditions as mentioned in this paper. The optimum aging temperature of the CoCrFeNiCuTi alloy is about 750 ° C and the hardness obtained at 750 ° C for 12 hours is 12 hours faster than the adjacent 650 ° C and the aging time at 850 ° C for 12 hours.

Keywords： high entropy alloy；Aging time；Aging temperature；hardness

目录

第一章绪论 1

1.1引言 1

1.2高熵合金理论 2

1.2.1定义 2

1.2.2制备方法 2

1.2.3高熵合金的分类 3

1.3高熵合金特性 5

1.3.1高熵效应 6

1.3.2缓慢扩散效应 7

1.3.3晶格畸变效应 7

1.3.4鸡尾酒效应 7

1.4研究现状： 7

1.5应用前景 10

1.6研究内容 11

第二章实验方法及过程 12

2.1合金元素选择与成分