摘要本研究采用等离子喷涂方法制备了 AlCoCrFeNiTi 涂层，并分析了其微观组织 结构，测试了其高温摩擦磨损、结合强度及显微硬度等力学性能。

研究发现，等离子喷涂 AlCoCrFeNiTi 涂层宏观表面形貌比较粗糙。涂层总体 上比较致密，同时也存在一些缺陷，如基体与涂层界面上的孔隙、涂层中粒子边缘 的氧化等。与喷涂粉末的物相相比较，涂层的物相发生了改变，生成了 BCC1 相、 有序 BCC 相和 FCC 相。80635

力学性能测试发现，由于涂层/基体界面处的粒子与基体之间的啮合较为紧密且 缺陷较少，使得基体与涂层的结合强度高于拉伸试样其他部分；从基体到涂层表面， 显微硬度整体呈上升趋势；涂层的平均硬度为 644HV；由于热喷涂涂层的边缘效应 致使其边缘处的硬度稍有下降，该处硬度为 630HV；随摩擦磨损试验温度变化，涂 层呈现出不同的磨损机制，而磨损机制的不同主要与涂层的硬度、氧化程度等有关； 摩擦磨损测试结果表明，AlCoCrFeNiTi 涂层在 700℃下抗摩擦磨损能力最强。

毕业论文关键词：高熵合金；等离子喷涂；显微硬度；结合强度；摩擦磨损

Abstract An AlCoCrFeNiTi coating was prepared by atmospheric plasma spraying。 The microstructure of the as-sprayed coating was analyzed and the mechanical  properties such as high temperature wear resistance, bonding strength and microhardness were tested。

It is found that the macroscopic morphology of the coating was coarse。 The coating was compact and some defects such as pores, oxides were observed in the coating。 Compared with the phase of the feedstock powder, that of the  as-sprayed  coating changed and BCC1 phase, ordered BCC phase and FCC phase were formed。

Results show that a high bonding strength was obtained because of the  good bonding condition between the coating and the substrate。 The microhardness of the coating increased from the substrate to the coating surface and the average microhardness of the coating was 644HV。 Due to edge effect of thermally-sprayed coating, the microhardness of the edge of the coating decreased to 630HV。 With the increase of the wear temperature, the coating showed different wear mechanisms。 Results show that the coating exhibited the best wear resistance at 700oC。

Keywords: high-entropy   alloy;   atmospheric   plasma   spraying;    microhardness; bonding strength; friction and wear

目 录

第一章 绪论 1

1。1 选题背景与意义 1

1。2 高熵合金研究概述 2

1。2。1 高熵合金发展的开端及概念 2

1。2。2 高熵合金的组织结构 2

1。2。3 高熵合金的性能及特点 3

1。2。4 高熵合金国内外研究进展 4

1。2。5 高熵合金的发展前景及应用 5

1。3 等离子喷涂 5

1。3。1 等离子喷涂概念及特点 5

1。3。2 国内外等离子喷涂设备的研究情况 5

1。3。3 等离子喷涂制备耐磨涂层 7

1。4 研究目的与内容 7

第二章 实验材料、设备及方案 8

2。1 实验材料及设备 8