摘 要 本研究采用机械合金化粉末通过等离子喷涂技术沉积了CoCrFeNiCu 涂层，并研究了喷涂粉末的微观结构、喷涂态涂层的微观组织结构以及涂层的显微硬度和其抗腐蚀能力。 研究发现，CoCrFeNiCu 喷涂粉末球磨完成后各金属元素混合较均匀，符合等离子喷涂要求。喷涂后喷涂态涂层表面呈粗糙状态，大部分粒子熔化较好。CoCrFeNiCu涂层与基体的结合方式为机械结合，涂层内部存在不规则孔隙、粒子间未结合界面等孔隙。喷涂态涂层内部存在 FCC 相析出物。从基体到涂层，显微硬度整体上呈上升趋势，其中基体硬度在 173.5HV 左右，基体/涂层界面硬度为 357.7HV，涂层内部的最大硬度为 429.1HV。涂层边缘的硬度只有 413.5HV 左右，这可能是由于热喷涂涂层的边缘效应所致。CoCrFeNiCu 高熵合金涂层与 316 钢相比具有较正自腐蚀电位，以及更小的腐蚀电流密度和腐蚀速率。CoCrFeNiCu 高熵合金涂层在 3.5%NaCl 溶液中的腐蚀以点蚀为主。与 316钢相比，CoCrFeNiCu 高熵合金涂层耐腐蚀性能更优。58955
毕业论文关键词：CoCrFeNiCu 涂层；显微组织；显微硬度；耐腐蚀性
Abstract In this study, CoCrFeNiCu coating was deposited by plasma spray technology using the ball milled powder as the feedstock powder. The microstructure of the ball milled powder and the as-sprayed coating was analyzed and the microhardness and corrosion resistance of the coating were investigated. It was found that the metal elements are evenly mixed after the particles was ball milled, which is suitable for plasma spraying. After spraying, the coating surface was rough, and most of the particles were melted. The bonding between CoCrFeNiCu coating and substrate was mechanical bonding. And there were irregular pores and defects due to no bonding of interface between particles in the coating. There existed FCC phase precipitates in the coating. From the substrate to the coating, the microhardness of the overall coating exhibited upward trend. Where the matrix hardness was around 173.5HV, the substrate/coating interface hardness was 357.7HV, and the maximum hardness of the coating was 429.1HV. The edge hardness of the coating is only about 413.5HV, which may be due to the edge effect of the thermally-sprayed coating. CoCrFeNiCu high entropy alloy coating has a more positive corrosion potential and less corrosion current density and corrosion rate compared with 316 stainless steel. Corrosion of CoCrFeNiCu high entropy alloy coating in 3.5%NaCl solution is mainly pitting corrosion. Compared with 316 steel, the corrosion resistance of CoCrFeNiCu high entropy alloy coating is better.
Keywords：CoCrFeNiCu coating; microstructure; microhardness; corrosion resistance
目录
第一章绪论.1
1.1引言.1
1.2等离子喷涂的原理、特点及应用.1
1.2.1等离子喷涂的原理...1
1.2.2等离子喷涂的特点...2
1.2.3等离子喷涂电弧的特点...3
1.2.4等离子喷涂的应用...4
1.3高熵合金的概念、结构及性能.4
1.3.1高熵合金的概念...5
1.3.2高熵合金的结构和性能...5
1.4高熵合金的发展现状.6
1.5课题内容及研究意义.8
第二章实验材料、设备及方案...9
2.1实验材料及所用设备.9
2.1.1实验材料...9
2.1.2等离子喷涂设备...9
2.1.3其他设备和仪器...9
2.2等离子喷涂沉积涂层...10
2.2.1基体的预处理.10
2.2.2粉末的预热.11
2.2.3涂层的沉积.11
2.3涂层物相、形貌分析...12
2.4涂层的显微硬度测定...12
2.5涂层的腐蚀...13
第三章机械合金化CoCrFeNiCu粉末的微观组织..14
3.1球磨粉末的微观形貌...14 等离子喷涂CoCrFeNiCu涂层组织及性能研究:http://www.youerw.com/cailiao/lunwen_63979.html