激光熔覆Co-Cr-W合金涂层组织及热疲劳性能  

Microstructure and thermal fatigue resistance of Co-Cr-W alloy coating by laser cladding

作　　者：朱天辉[1] 虞钢[1] 何秀丽[1] 李少霞[1] 宁伟健[1] 郑彩云[1] 王高飞[1] 刘昊[2] 

机构地区：[1]中国科学院力学研究所先进制造工艺力学重点实验室,北京100190 [2]中国矿业大学机电工程学院,江苏徐州221116

出　　处：《材料热处理学报》2015年第11期219-224,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(11272316;11272317)

摘　　要：针对钢质热负荷部件易产生热疲劳损伤的问题,采用同步送粉激光熔覆工艺,在活塞用中碳钢38Mn VS6表面制备了Co-Cr-W抗热疲劳合金涂层。利用光学显微镜、SEM、EDS及XRD对熔覆层显微组织和成分分布进行了分析,利用显微硬度计和实验室开发的激光热疲劳实验平台对熔覆层的显微硬度和热疲劳性能进行了测试。结果表明,熔覆层与基体冶金结合,无气孔、裂纹等缺陷。由于固溶强化、弥散强化效应,熔覆层具有较高的强度。送粉率为5.9 g/min时,涂层显微硬度在530~590 HV0.1之间,是基体硬度的2倍左右;熔覆层试样抗热疲劳性能相较于基体材料试样得到了显著的提高。Considering the problem of thermal fatigue damage for some steel components,the Co-Cr-W alloy coating was fabricated on surface of medium-carbon steel 38 Mn VS6 for piston by laser cladding with synchronous powder feeding method. The microstructure and element distribution of the coating were investigated by means of optical microscopy,SEM,EDS and XRD. The hardness and thermal fatigue resistance of the coating were measured by the Vickers hardness tester and laser thermal fatigue experiment platform. The results show that the coating is metallurgically bonded to the substrate and free of crack and pore. The coating strength is improved due to the solid solution and dispersion strengthening. With the powder feeding rate of 5. 9 g / min,the microhardness of the coating is 530-590 HV0. 1,which is twice as much as that of the substrate. Meanwhile,the thermal fatigue resistance of the coating is improved significantly compared with that of the substrate.

关 键 词：激光熔覆 Co-Cr-W合金 显微组织 热疲劳性 

分 类 号：TG174.44[金属学及工艺—金属表面处理]