超音速激光沉积WC/Stellite 6复合涂层显微组织特征的研究  

Microstructural Characteristics of WC/Stellite 6 Composite Coating Prepared by Supersonic Laser Deposition

作　　者：李祉宏[1,2] 杨理京[1,2] 李波[1,2] 张群莉[1,2] 姚建华[1,2] 

机构地区：[1]浙江工业大学激光加工技术工程研究中心,浙江杭州310014 [2]浙江省高端激光制造装备协同创新中心,浙江杭州310014

出　　处：《中国激光》2015年第11期148-155,共8页Chinese Journal of Lasers

基　　金：浙江省自然科学基金青年基金(LQ13E050012);江苏省光子制造科学与技术重点实验室开放基金(GZ201307);浙江省博士后科研择优资助项目(Z42102002)

摘　　要：超音速激光沉积技术(SLD)将激光技术与冷喷涂技术相结合,在保持冷喷涂固态沉积的优势下,极大地拓展了单一冷喷涂技术的可喷涂材料范围。采用超音速激光沉积技术制备了单一冷喷涂难以制备的WC/Stellite 6金属基复合涂层(MMC),并与激光熔覆(LC)涂层在宏观形貌、显微组织、界面稀释、未熔WC占比、涂层抗裂纹扩展性能等方面进行对比研究。研究表明:具有固态沉积特点的超音速激光沉积涂层避免了热加工过程中的WC分解与溶解问题,在采用相同比例的WC/Stellite 6复合材料情况下,超音速激光沉积涂层中WC体积占比为27.6%,高于激光熔覆层的3.7%;激光熔覆层稀释率约为8.9%,而超音速激光沉积涂层无宏观稀释区;大载荷压痕测试结果显示激光熔覆涂层压痕处出现大量放射状裂纹而超音速激光沉积涂层无裂纹出现,表明超音速激光沉积涂层抗裂纹扩展能力优于激光熔覆涂层。Supersonic laser deposition （SLD） is a new coating and fabrication process in which a supersonic powder stream produced by cold spray （CS） impinges on a substrate simultaneously heated by laser irradiation to expand the range of materials deposited under solid-state during SLD process. WC/Stellite 6 metal matrix composite （MMC） coating prepared by SLD and laser cladding （LC） are studied and compared in terms of macro-morphology, microstructure, interface dilution and unmelted WC proportion of coating, crack propagation resistance. The results show that the dense, crack-free coatings with uniform distribution of WC are achieved by SLD coating because of solid-state deposition, which can avoid the root causes of WC decomposition and dissolution in high temperature processing. The dilution rate of laser cladding coating is about 8.9%, while no macroscopic dilution zone is found in SLD coatings. The unmelted WC proportion of SLD coatings is about 27.6%, which is much higher than that of LC coatings. The results show that a great number of cracks around the indentation in LC coating while no cracks is found in SLD coatings under 50 kg load indentation indicate that the crack propagation resistance of supersonic laser SLD coating is superior to that of LC coating.

关 键 词：激光光学 金属基复合材料 超音速激光沉积 STELLITE 6 WC 微观结构 

分 类 号：TG146.1[一般工业技术—材料科学与工程] TN249[金属学及工艺—金属材料]