激光熔敷原位合成WC增强铁基复合涂层的组织和性能  

Microstructure and Performance of WC Reinforced Fe-based Composite Coating Synthesized In-situ Produced by Laser Cladding

作　　者：陈希章[1,2] 胡科[2] 袁其兵 

机构地区：[1]温州大学机电工程学院,浙江温州325025 [2]江苏大学材料科学与工程学院,江苏镇江212013

出　　处：《中国表面工程》2016年第4期118-124,共7页China Surface Engineering

基　　金：温州市2014年激光与光电产业集群重大科技专项计划(J20140016);江苏省高端结构材料重点实验室2014年度开放基金(hsm1406)

摘　　要：利用激光熔敷原位合成技术,以一定比例的Fe、C、W等粉末为熔敷材料,在Q235钢基体上原位反应合成WC颗粒增强型铁基涂层。分别采用OM、SEM、XRD、EDS、显微硬度、摩擦磨损等分析测试方法对熔敷金属的组织、成分和力学性能等进行研究。结果表明:合适的工艺参数下,能够得到无缺陷的与基体冶金结合的熔敷层金属,熔敷层内的硬质相主要为Fe_3W_3C、W_2C和很多晶粒细小WC;W粉颗粒尺寸影响熔敷层中WC的生成量,小尺寸的钨粉颗粒可以生成更多的WC,当W粉颗粒尺寸达到23μm时,出现了细小的六边形的WC形貌;适当提高Cr的含量可以增加熔敷层的硬度,但会减少WC的生成数量。激光熔敷层的硬度相比基体有很大提高,平均硬度可达到921 HV;耐磨性能远高于基体,当出现细小的六边形WC颗粒时,耐磨性能可达到基体的602倍。WC particulates reinforced Fe-based coating was in-situ synthesized on Q235 steel by laser cladding using a certain proportion of Fe, C, W powders. The microstructure, compositions and mechanical properties of the cladding metal were analyzed by OM, SEM, XRD, EDS, micro hardness testing, and friction and wear. The results show that the cladding layer and the base metal are metallurgically bonded without defects under suitable process parameters. The hard phase in the cladding layer is mainly composed of Fe3W3C, W2C and fine WC. The formation of the WC in the cladding layer is affected by the size of W particles, and the W particles of smaller sizes generate more WC. The morphology of the hexagonal WC with fine grains is formed when the W particles reach 23 μm. Increasing the content of Cr improves the hardness of the cladding layer, but reduces the amount of WC generated. Reaching 921 HV on average, the hardness of the laser cladding layer is greatly improved compared with that of the base metal. The wear resistance is also much higher than that of the base metal, 602 times as much as that of the base metal when the fine-grain hexagonal WC particles are generated.

关 键 词：激光熔敷 原位反应 显微硬度 耐磨性 

分 类 号：TG174.44[金属学及工艺—金属表面处理]