铝合金表面MOSi_2/SiC复合涂层的激光熔覆制备  

Fabrication of MoSi_2/SiC composite coating on aluminum alloys by laser cladding

作　　者：杨森[1] 王三军[1] 龚涛[2] 刘文今[2] 

机构地区：[1]内蒙古工业大学材料科学与工程学院,内蒙古呼和浩特010051 [2]清华大学机械工程系,北京100084

出　　处：《材料热处理学报》2007年第B08期218-221,共4页Transactions of Materials and Heat Treatment

基　　金：内蒙古自然科学基金(200508010704)

摘　　要：利用激光熔覆技术在铝合金表面制备MoSi_2/SiCp复合涂层,对涂层的微观组织形成规律及其主要工艺参数对涂层组织和性能的影响进行了研究。实验结果表明,对试样进行搭接预热和在熔覆粉末中添加助熔剂CaF_2是提高熔覆层质量的主要途径。采用多道搭接预热熔覆工艺和预置涂层法可以在铝合金表面获得具有完全冶金结合的原位自生SiC颗粒增韧的硅化钼陶瓷复合涂层,涂层组织主要由Mo(Si,Al)_2、SiC、α-Al、Mo_5Si_3等相组成。熔覆层显微硬度较基体材料的显微硬度有大幅度提高,涂层显微硬度最大可达850HV_(0.2)。In order to improve high temperature oxidation and wear resistance of AI alloys, a MoSi2/SiC composite coating was fabricated on aluminum alloy using laser cladding. Microstructure characteristics of the coating and the effects of processing parameters were also investigated. The experimental results showed that MoSi2/SiCp composites coating can be in-situ synthesized from mixture powders of molybdenum, silicide and graphite by laser cladding. The quality of the coating was controllable through preheating the substrate and adding CaF2 in precursor powder. The microstructures of the coating were composed of Mo（Si,Al）2, SiC, α-Al, and Mo5Si3 phases. The maximum microhardness of the coating was about 850HV0.2.

关 键 词：激光熔覆 原位自生 二硅化钼 SIC 

分 类 号：TG146.1[一般工业技术—材料科学与工程]