结晶器铜板表面激光熔覆Ni-Co-Al_2O_3复合涂层的微观组织及性能

Microstructure and property of Ni/Co/Al_2O_3 laser cladding layer on the surface of mold copper plate

以Ni-Al2O3纳米复合镀层为中间涂层,在结晶器铜板表面激光熔覆Co42粉末制备Ni-CoAl2O3复合涂层,利用金相显微镜,扫描电镜、显微硬度仪及电化学腐蚀测试系统对涂层的微观组织、硬度及耐蚀性能进行了分析,研究结果表明,Ni-Al2O3纳米复合镀层晶粒细小,微观组织致密、均匀。激光功率为4.5kW,扫描速度为240mm/min时形成的激光熔覆层与基层形成了良好的冶金结合,激光熔覆层晶粒进一步细化,熔覆层的平均显微硬度高达1 000 HV,耐蚀性能优良。

Ni/Co/Al2O3 composite coatings are prepared on the surface of mold copper plate with laser cladding of Co42 powders as cladding layer and Ni/Al2O3 nanocomposte as interlayer,the microstructure,hardness and corrosion resistance of layers are analyzed by OM,SEM,microhardness tester and electrochemical system.The results indicate that Ni/Al2O3 nanocomposte was compact and uniform with fine grain.Laser cladding layer.Under the condition of 4.5kW laser power and 240mm/min scanning speed,the laser cladding layer was metallurgical bonded to the substrate excellently,the grain of the laser cladding layer was refined,the laser cladding has a average microhardness value of 1 000 HV and excellent corrosion resistance.