模具钢表面激光原位制备Ni基合金复合涂层的微结构与性能  

Microstructure and Property of Laser in situPreparation of Ni-Based Alloy Composite Coating on Die Steel Surface

作　　者：刘洪喜[1] 唐淑君[1] 蔡川雄[1] 张晓伟[1] 王传琦[1] 蒋业华[1] 

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093

出　　处：《中国激光》2013年第6期156-161,共6页Chinese Journal of Lasers

基　　金：国家自然科学基金(51165015);昆明理工大学分析测试基金(2011008)资助课题

摘　　要：通过控制Ni基自熔性合金粉末中Al、Mo含量,在H13钢表面原位制备了含γ′-Ni3Al强化相的激光熔覆涂层。借助光学显微镜(OM)、扫描电镜(SEM)和X射线衍射仪(XRD)分析了不同熔覆层的显微组织及物相结构。结果表明,4种成分的熔覆层均呈现出平整致密、无明显缺陷的宏观特征。Ni基自熔性合金粉末中加入Al易于生成γ′-Ni3Al相,当Al含量达到一定程度后,涂层中开始出现β-NiAl相,同时Fe主要以(Fe,Cr)固溶体形式存在,(Ni,Cr)固溶体极少。加入Mo后,涂层中几乎未见β-NiAl相;Al含量较少时,Mo主要与Fe结合形成Mo-Fe金属间化合物;当Al含量增加至开始出现β-NiAl相时,Mo便与Al结合形成AlMo3。同时Mo-Fe金属间化合物的存在也导致(Fe,Cr)固溶体较同等Al含量下未加入Mo时少,(Ni,Cr)固溶体含量较未加入Al时多。涂层摩擦系数均低于基体,最高显微硬度为基体的4.3倍,抗磨性提高了3.8倍。In situ laser cladding coating with γ＇＇- Ni3 AI strengthening phase is fabricated by controlling the A1 and Mo contents in Ni-based self-fluxing alloy powder on H13 die steel surface. The microstructure and phase structure of the four kinds of chemical composition powder are analyzed by means of optical microscopy （OM）, scanning electron microscopy （SEM） and X-ray diffractometry （XRD）. The results indicate that the macroscopic morphologies of the four kinds of laser cladding coatings are smooth, dense and without obvious macroscopic defects. Ni-based self-fluxing alloy powder with A1 added is easier to generate γ＇-Ni3 A1 phase. When the A1 content reaches a certain degree, β-NiA1 phase is found in the coating. Fe mainly exists as （Fe, Cr） solid solution, while the （Ni, Cr） phase is small. The β-NiA1 phase is almost not found when Mo is added in the coating. When the Al content is small, Mo and Fe combining to form Mo-Fe are intermetallic compound. But when β-NiA1 phase is generated in the coating as the AI content increases, Mo and A1 combine to form AIMo3. The existence of Mo-Fe intermetallic compound makes （Fe, Cr） solid solution less than that of the same AI content without Mo, but the （Ni, Cr） solid solution is more than without Al. The friction coefficients of all cladding coating samples are lower than the H13 steel substrate. The highest microhardness of the coating increases by 3.3 times and the wear resistance increases by 3.8 times, respectively, in comparison with the substrate.

关 键 词：材料 激光熔覆 H13钢 NI3AL 金属间化合物 显微组织 

分 类 号：O436[机械工程—光学工程]