JIUJIANG UNIVERSITY
毕 业 设 计
题 目 超音速火焰喷涂WC – Co涂层的
磨粒磨损性能研究
英文题目Seattle Flame Spray WC - Co Coating Of
Particle Attrition Performance Study
院 系 机械与材料工程学院 专 业 焊接技术及自动化 姓 名 XX 年 级 2008级（B0861班） 指导教师 王洪涛
二零一零年十二月
摘 要
利用超音速火焰喷涂工艺制备了WC-Co涂层，测定了涂层孔隙率、显微硬度及干摩擦磨损过程爱中涂层材料失重，得出涂层干摩擦因数随时间的变化系，分析了涂层摩擦磨损机制。结果表明，WC-Co涂层致密，平均孔隙率为1.29%，显微硬度达1140HV(测试载荷2.94N)，干摩擦条件下材料失重低于电镀Cr镀层2个数量级；摩擦初期，干摩擦因数迅速增加，主要磨损特征是粘结相富Co区的犁沟切削，摩擦中后期，摩擦副间实际接触面积增E大，摩擦因数变化较小，磨损趋于稳定WC-Co涂层的主要磨损机制是疲劳磨损和犁沟切削。
【关键词】超音速火焰喷涂；WC-Co涂层；磨粒磨损
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目 录
前言········································································1 第一章 绪论································································2 1.1 引言··································································2 1.2超音速喷涂技术原理····················································2 1.3超音速火焰喷涂涂层性能及特点··········································3 1.3.1超音速火焰喷涂涂层性能··········································4
1.3.2超音速火焰喷涂特点··············································5 1.4超音速喷涂的工艺控制··················································5 1.4.1超音速火焰喷涂（HVOF）工艺控制·································· 5 1.4.2超音速空气喷涂（HVAF）工艺控制·································· 6 1.4.3超音速等离子弧喷涂工艺控制······································6 1.5 超音速火焰喷涂技术的发展和最新研究及应用·····························7
1.5.1超音速火焰喷涂技术的发展历史····································7
1.5.2超音速火焰喷涂技术的最新研究····································8 1.5.3超音速火焰喷涂技术的最新应用····································9 1.6 关于HVOF喷涂涂层结构涂层研究······································10
1.6.1关于喷涂过程的粒子束行为·······································10
1.6.2关于纳米结构涂层的形成过程与机理·······························11 1.6.3关于影响HVOF喷涂层的因素及机理研究·························· 12 1.7 本文研究的主要内容及意义············································15
第二章 超音速火焰喷涂WC-Co涂层的磨粒磨损试验内容和方法···········17 2.1试验材料和仪器·······················································17
2.1.1试验材料·······················································17 2.1.2试验仪器·······················································17
2.2试验内容和方法·······················································17
2.2.1涂层的制备·····················································17 2.2.2磨粒磨损试验过程及方法·········································19
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第三章 超音速火焰喷涂WC-Co涂层的磨粒磨损实验结果及分析···········22 3.1 WC-Co表面形态观察及分析···········································22
3.1.1粉末原始形态···················································22 3.1.2磨粒原始形态···················································22 3.1.3扫描电子显微镜组织观察·········································22
3.2磨粒磨损结结果分析··················································23
3.2.1载荷对涂层磨损失重量的影响·····································23 3.2.2燃气流量对涂层磨损失重量的影响·································24
结论·······································································25 参考文献··································································26 谢辞·······································································27
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前 言
自从超音速火焰喷涂技术诞生以来，其应用范围就在不断的扩展之中，超音速喷涂已经成为热喷涂技术的主流发展方向，目前在国外已经渗透到各种领域，如石油化工、机械、印刷、航空航天、冶金、电力、塑料，等工业部门。
现代科学技术和现代工业的发展，对各种设备零部件的表面性能要求越来越高，特别是在高速度、高温、高压、重载、腐蚀介质等条件下工作的零件，其材料的破坏往往白表面开始，如磨损、腐蚀、高温氧化等，表面的局部损坏又往往造成整个零件失效，最终导致设备停产。因此，改善材料的表面性能，可有效地延长其使用寿命、节约资源、提高生产力、减少环境污染。超音速火焰喷涂技术是一种可在材料表面高效率地形成涂层的工艺方法，该工艺将材料加热并雾化成熔化或半熔化的粒子，经加速后撞击基体(或已形成的涂层)表面，扁平化后沉积在表面形成涂层. 其突出的特点是：①火焰速度高，可达1500m/s以上，可将喷涂粒子加速到高达300~500m/s；②温度比等离子喷涂低很多，约2760oC，可有效防止喷涂过程中粒子的氧化，特别适合喷涂加热后易于分解的金属陶瓷涂层；③涂层的结合强度高(>70MPa)，致密性好，耐磨性能优越。
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