摘要本研究利用机械合金化法制备了 AlCoCrFeNiSi 高熵合金粉末，采用大气等离子 喷涂沉积了 AlCoCrFeNiSi 高熵合金涂层。观察、分析了 AlCoCrFeNiSi 高熵合金粉末 在制备过程中的组织结构变化，以及高熵合金涂层的组织结构特征，并对涂层显微硬 度和耐腐蚀性两方面性能进行了研究。80922

研究发现，在制备 AlCoCrFeNiSi 高熵合金粉末的过程当中，随着高能球磨时间 的增加，粉末颗粒形状渐渐趋向于椭球形，粉末颗粒分布逐渐趋向于均匀。同时随着 球磨时间的增加，粉末的粒度呈现先增加后减少的规律，球磨 20h 后，粉末粒度变化 速度减缓。

等离子喷涂后，由于等离子喷涂过程中发生了元素的偏聚现象，AlCoCrFeNiSi 高熵合金涂层内部析出了新的物相，主要是 Co-Ni 和 Fe-Cr 的体心立方晶格合金相， 以及 Fe-Ni 的面心立方晶格合金相等一些更加稳定的结构。同时，在等离子喷涂过后， 基体表面硬度明显增大，并且有着优异的耐腐蚀性能。

毕业论文关键词：APS；AlCoCrFeNiSi 高熵合金；显微硬度；耐腐蚀性

AbstractIn this study, mechanical alloying was used prepare the AlCoCrFeNiSi high entropy alloy powder and atmospheric plasma spraying was employed to deposit the high-entropy alloy coating。 Microstructural changes of the AlCoCrFeNiSi high-entropy alloy powder during the manufacturing process were investigated。 Meanwhile, the  microstructure and the properties such as microhardness and corrosion resistance of the coating were analyzed and tested。

It is found that during the preparation of the AlCoCrFeNiSi high entropy alloy powder, with the increase of the ball milling time, the shape of the powder particles tend to be ellipsoid and gradually evenly distributed。 Meanwhile, with the increase of the milling time, the size of the powder particles followed a repeatable pattern of increases at first and decreased afterwards, and after 10 hours of milling time the change in size slowed down。

After the plasma spray process, the interior of the AlCoCrFeNiSi high entropy alloy coating inside precipitated new phases, because of the segregation of elements in the plasma spraying process。 These phases mainly consisted of the Co-Ni and the Fe-Cr body-centered cubic lattice alloy, as well as some other phases with more stable structure, such as the Fe-Ni face-centered cubic lattice alloy。 Moreover, after spray, the surface hardness of the substrate was significantly increased and the corrosion resistance of the coating was excellent。

Keywords: APS; AlCoCrFeNi high entropy alloy; microhardness; corrosion resistance

目 录

第一章  绪论 1

1。1  选题背景、研究现状和研究意义 1

1。2  机械合金化概述 2

1。2。1  机械合金化概念及原理 2

1。2。2  机械合金化存在问题 2

1。2。3  高能球磨概念 2

1。3  等离子喷涂概述 3

1。3。1  基本概念 3

1。3。2 等离子喷涂的分类 4

1。3。3  等离子喷涂技术特点及应用 5

1。3。4  等离子喷涂技术的发展及展望 5

1。4  高熵合金涂层概述 6

1。4。1  高熵合金概念 6

1。4。2  高熵合金制备方法