激光功率对Co基梯度耐磨涂层性能的影响  

Effect of laser power on properties of Co-based gradient wear-resistant coatings

作　　者：张昌春 石岩[2] 王洪新 ZHANG Changchun;SHI Yan;WANG Hongxin(College of Mechanical and Vehicular Engineering,West Anhui University,Lu ＇an 237012,China;Electric Engineering,Changchun University of Science and Technology,Changchun 130022,China)

机构地区：[1]皖西学院机械与车辆工程学院,六安237012 [2]长春理工大学机电工程学院,长春130022

出　　处：《激光技术》2018年第4期494-499,共6页Laser Technology

摘　　要：为了分析激光功率对Co基梯度耐磨涂层组织和性能的影响,采用激光熔覆在20Cr Mn Mo钢表面依次熔覆St6,St12B,Co47+WC(质量分数为0.05)合金粉末制备厚度约为2.4mm的Co基梯度耐磨涂层,进行了微观组织分析、显微硬度测试、摩擦磨损试验。结果表明,不同激光功率下涂层表面均没有出现裂纹且各涂层中晶体形貌相似,表层出现致密的等轴晶、过渡层出现粗大的柱状晶、底层出现平面晶和树枝晶;600W时耐磨层中发现未熔WC颗粒,800W耐磨层发现CoW_2B_2硬质相;在600W^800W范围内,激光功率越高,涂层整体的显微硬度和耐磨性越好;激光功率为800W时,耐磨层显微硬度达到730HV_(0.1),涂层耐磨性相对于基体提高了300%。此研究结果对激光熔覆制备Co基梯度耐磨涂层提供了参考依据。In order to analyze effect of laser power on microstructure and properties of Co-based gradient wear-resistant coatings,alloy powders of St6,St12 B and Co47＋ WC（ mass fraction of 0. 05） were claded on the surface of 20 Cr Mn Mo steel.Co-based gradient wear-resistant coatings with the thickness of about 2. 4 mm were prepared to do microstructure analysis,microhardness test,friction and wear test. The results show that there is no crack on the surface of the coatings under different laser powers. The morphology of the crystals in each coating is similar： dense equiaxed grains in the surface layer,large columnar crystals in the transition layer,and plane and dendrites in the bottom layer. The unmelted WC particles are found in the wear-resistant layer at 600 W. The hard phase of CoW2B2 is found in the wear-resistant layer at 800 W. From the study about the properties of the coatings,the higher the laser power,the better the microhardness and wear resistance of the coatings in the range of 600 W to 800 W. When laser power is 800 W,microhardness of the wear-resistant layer is 730 HV（0. 1）,and wear resistance of the coating is 300% higher than that of the matrix. The results of this study provide a reference for the preparation of Co-based gradient wear-resistant coatings by laser cladding.

关 键 词：激光技术 Co基梯度耐磨涂层 激光功率 显微组织 性能 

分 类 号：TG156.99[金属学及工艺—热处理]