镍包WC激光熔覆工艺及熔覆层特性研究.pdf 全文免费在线阅读

  本文关键词：镍包WC激光熔覆工艺及熔覆层特性研究，，由笔耕文化传播整理发布。

网友Alphago近日为您收集整理了关于镍包WC激光熔覆工艺及熔覆层特性研究的文档，希望对您的工作和学习有所帮助。以下是文档介绍：中图分类号:TG665 论文编号:102870515-S029学科分类号:080201 硕士学位论文镍包WC激光熔覆工艺及熔覆层特性研究研究生姓名冯君学科、专业机械制造及其自动化研究方向特种加工指导教师田宗军教授南京航空航天大学研究生院机电学院二О一五年三月Nanjing University of Aeronautics and AstronauticsThe Graduate SchoolCollege of Mechanical and Electrical EngineeringResearch on NicoatedWC lasercladding processandcladdinglayer characteristicsA Thesis inMechanical Manufacture and AutomationbyFengJunAdvised byProf. Tian ZongjunSubmitted in PartialFulfillmentof the Requirementsfor the DegreeofMaster of EngineeringMarch, 2015承诺书本人声明所呈交的博/硕士学位论文是本人在导师指导下进行的研究工作及取得的研究成果。除了文中特别加以标注和致谢的地方外,论文中不包含其他人已经发表或撰写过的研究成果,也不包含为获得南京航空航天大学或其他教育机构的学位或证书而使用过的材料。本人授权南京航空航天大学可以将学位论文的全部或部分内容编入有关数据库进行检索,可以采用影印、缩印或扫描等复制手段保存、汇编学位论文。(保密的学位论文在解密后适用本承诺书)作者签名:日期:南京航空航天大学硕士学位论文I摘要激光熔覆技术作为提高金属表面性能的方法,可有效提高零件的硬度、耐磨和抗蚀性,具有广泛的应用前景,因此,研究涂层成型工艺及涂层性能是很有意义的。本文阐述了激光熔覆技术的工艺方法及特点,分析了激光熔覆涂层裂纹的形成机理,并对熔池及金属材料在激光作用下的熔凝机理进行了研究。通过工艺试验,制备了高硬质镍包WC涂层,并对涂层微观组织形貌及成分、涂层硬度、涂层耐磨性进行了较为系统的分析研究,主要研究内容如下:(1)从金属材料在激光作用下的熔凝机理出发,对激光熔覆的熔池形成以及裂纹的产生机理进行研究,为工艺试验提供一定的理论基础。(2)通过对激光功率、扫描速率、预热温度等工艺参数的正交试验,制备大量的镍包WC涂层,分析各工艺参数对涂层宏观形貌及裂纹敏感性的影响。(3)研究涂层微观组织形貌,通过SEM、EDS、XRD的检测,分析涂层的成分及物相的构成,同时分析工艺参数对微观组织的影响。(4)对涂层硬度进行研究,分析工艺参数对涂层显微硬度的影响,及涂层不同深度的显微硬度分布。(5)测试涂层的耐磨性能,对不同硬度的涂层与基体材料的耐磨性进行比较,比较其摩擦系数、磨损量和磨损形貌的差别。关键词:激光熔覆,组织形貌,显微硬度,耐磨性能镍包WC激光熔覆工艺及熔覆层特性研究II南京航空航天大学硕士学位论文IIIAbstractLaser cladding technology, as a way to improve the performance of the metal surface, which can effectively improve the hardness, wear resistance and corrosion resistance of parts, has wide application prospect.Therefore, the studyof coating forming process and coating properties is very meaningful. This paper expounds the methods and characteristics of laser cladding technology, analyzes the formation mechanism of laser cladding coating crack, and studies the fusingmechanism ofmolten pool and metal materials under the effect of laser. Through the process experiment, high rigid Ni capped WC coating was prepared, andhave a systematic analysis and researchofthe coating microstructure morphology position, coating hardness, wear resistance coatingwere carried on. The main research content is as follows: (1) From the fusingmechanism of metal materials under the effectof laser, the laser cladding of the molten pool formation and mechanism of crack formation werestudied, providing certain theoretical basis for process test. (2) By orthogonal experimentoflaser power, scanning rate, preheat temperature and other process parameters,lots of Ni cappedWC coatingwas processed, and the analysis for various process parameters on the coating and the influence of the crack sensitivitywere conducted. (3) Research on coating microstructure morphology by SEM, EDS and XRD testingand analysis of position and pos

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  本文关键词：镍包WC激光熔覆工艺及熔覆层特性研究，由笔耕文化传播整理发布。