摘要铜结晶器在现代工业领域中有着重要的运用。在钢铁工业中，铜结晶器是连铸机的重要核心。结晶器的工作条件比较恶劣，因此要求它具有具有较高的强度、硬度、耐磨性和耐腐蚀性能。过去，对铜结晶器表面的改善方法有：电镀法、热喷涂等。但是这些工艺方法处理之后还会存在很多的问题。使用等离子喷涂加激光重熔可以进一步的延长其使用寿命。目前结晶器铜板表面进行等离子喷涂激光重熔的研究并不多，研究的重点和难题是激光重熔参数对涂层性能的影响。本次试验在铜基体的表面等离子喷涂一层Cr3C2-NiCr涂层，然后利用不同的激光参数对涂层进行重熔处理。激光重熔后，通过金相显微镜、电镜扫描（SEM）分析涂层的微观形貌，再对涂层进行硬度、孔隙率、摩擦磨损测试之后，最后得出不同重熔参数涂层的硬度、孔隙率、和摩擦磨损系数。结果表明：激光重熔后，涂层的硬度分布均匀，孔隙得到改善，摩擦磨损系数稳定，基体中有粉末中的Ni元素。86154

毕业论文关键词：等离子喷涂；激光重熔；Cr3C2-NiCr涂层；铜基体。

Abstract Copper crystallizer has important use in the field of modern industry。In the iron and steel industry,Copper crystallizer is an important core of  Continuous casting machine。The crystallizer working conditions is poor,Therefore, it has requirements with high strength, hardness, wear resistance and corrosion resistance。In the past,Improved method on the surface of copper crystallizer are: plating, thermal spraying, etc。But, after these processing methods will also be a lot of problems。In order to prolong the service life of copper crystallizer,By plasma spraying and laser remelting method can be further to deal with the surface of the mold。At present the research on plasma spraying research more than laser remelting,Laser remelting process parameters is the research focus and difficult problem,This experiment on the surface of the copper substrate by plasma spraying a layer of Cr3C2 - NiCr coating,then,Study the effect of different laser parameters on the coating performance。After laser remelting, through metallographic microscope, scanning electron microscope (SEM) analysis of the microstructure of coating,Again on the coating hardness, porosity, and after the friction and wear test,Finally can get optimized parameters of laser remelting。 Results show that after laser remelting, uniform coating hardness distribution, pore is improved, the stable coefficient of friction and wear, Ni elements of the matrix of powder。

 Keywords：plasma spraying;laser remelting;Cr3C2-NiCr coating;Copper alloy。

目录

第一章  绪论 1

1。1结晶器的概述 2

1。2结晶器基体材料的表面处理方法 2

1。2。1电镀 2

1。2。2热喷涂 3

1。2。3激光重熔技术 4

1。3 激光重熔的国内外研究 5

1。4 本课题研究的意义与目的及主要研究内容 6

  第二章  试验材料设备及方法 6

2。1试验材料 7

2。1。1 基体材料 7

2。1。2等离子喷涂粉末 7

2。2等离子喷涂设备及工艺 8

2。2。1等离子喷涂设备 8

2。2。2等离子喷涂工艺参数