铜合金表面激光原位制备颗粒增强钴基合金涂层组织  

Ceramic Phase Reinforcing Co-Alloy Coating with Laser Inducing In-Situ Synthesis on the Surface of Copper Alloy

作　　者：李慧莉[1] 陈岁元[2] 刘大亮[2] 刘常升[2] 

机构地区：[1]东北大学研究院,辽宁沈阳110004 [2]东北大学材料与冶金学院,辽宁沈阳110004

出　　处：《中国激光》2008年第4期620-624,共5页Chinese Journal of Lasers

基　　金：国家自然科学和宝钢联合基金(50574020);中国博士后科学基金(20060390298);辽宁省新材料重点实验室开放基金资助项目

摘　　要：采用含有一定量纳米铝粉的钴基合金粉末作为涂层原材料，在结晶器用Cu—Cr合金表面利用激光搭接原位反应制备陶瓷相颗粒增强钴基合金涂层。通过金相显微镜、X射线衍射（XRD）仪、扫描电镜和显微硬度实验等分析手段对实验制备样品涂层的结构和形成机制进行了研究。结果表明，在优化了的激光制备工艺参数（电流175A，频率15Hz，脉宽3ms，速度4．0mm／s）及搭接率在20％～25％时，在Cu-Cr合金表面制备出了陶瓷相颗粒增强钻基合金涂层。Co基合金涂层和基体间形成了界面的冶金结合。涂层中原位生成了陶瓷相颗粒，最大颗粒的粒径在3μm左右，多数为细小且呈弥散分布的近似球形颗粒，起到了增强基体的作用。Co基合金的主要结晶方式是以原位生成的陶瓷相为中心，带动周围Co基合金液体结晶，反过来结晶后的合金对陶瓷相进行包裹，控制了陶瓷相的聚合，并使其弥散分布、颗粒细小化。Cu—Cr合金表面涂层的平均显微硬度由基体表面的94HV增到了300HV。Using Co-based alloy coating powder containing certain amount of nano-Al powder, the ceramic phase reinforcing Co-based alloy coating was produced by pulse laser overlapping in-situ synthesis on the surface of Cu-Cr alloy for crystallizer. The structure and forming mechanism of the coating were studied by means of optical microscope , X-ray diffraction （XRD）, scan electronic microscope and micro-hardness tester. The results show that the ceramic phase reinforcing Co-based alloy coating is produced on the surface of Cu-Cr alloy and the interface get metallurgical bonding between the Co-based alloy coating and Cu-Cr alloy substrate by using the optimized technological parameters of laser （current of 175 A, frequency of 15 Hz, pulse width of 3 ms, scan rate of 4.0 mm/s） and overlapping rate （20 % -25%）. The maximal size of the ceramic particles by in-situ synthesized is about 3 μm. Most of the ceramic particles are regular shape as ball and dispersive distribution. The principle of the Co-based alloy forms crystalline is that the ceramic phase as the center promotes the liquid Co-based alloy around it to be crystalline, and the crystallinic alloy enwrapps the ceramic phase. This process controls the aggregation of the ceramic phase, which causes the particles dispersive and small. The hardness of Co-based alloy coating （300HV） was improved obviously compare with that of Cu-Cr alloy substrate （94HV）.

关 键 词：激光技术 脉冲激光 CO基合金 原位生成 陶瓷相 

分 类 号：TG113.1[金属学及工艺—物理冶金] TG174.2[金属学及工艺—金属学]