合金成分对镍基合金激光熔覆涂层组织与性能的影响  

Effects of the Alloy Composition on the Microstructure and Properties of Laser Cladding Ni-based Alloy Coatings

作　　者：董刚[1,2] 严彪[1] 邓琦林[2] 余廷[2] 

机构地区：[1]同济大学材料科学与工程学院,上海200092 [2]上海交通大学机械与动力工程学院,上海200030

出　　处：《材料科学与工程学报》2011年第2期167-172,共6页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(50675136,50375096)

摘　　要：为了研究激光熔覆镍基合金涂层显微组织与性能之间的关系,本文选用Ni25、Ni45、Ni60镍基自熔性合金粉末作为熔覆材料,在同一工艺参数下在45#钢基体上制得Ni25、Ni45、Ni60合金激光熔覆涂层。利用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)、显微硬度计等方法对涂层的显微组织、物相组成、显微硬度等进行了研究。结果表明从Ni25到Ni60合金涂层,随着合金元素含量的提高,涂层微观组织逐渐由亚共晶转变为过共晶,γ-Ni奥氏体枝晶所占体积分数减少,尺寸细化,枝晶间的共晶组织和硬质相所占的体积分数增大,涂层和基体之间结合带的宽度越来越窄,熔覆层的显微硬度越来越高。Ni25、Ni45合金涂层的平均显微硬度分别为250HV和550HV左右,而Ni60合金涂层的平均硬度却高达750HV左右,为Ni25合金涂层的3倍。In order to study the relationship between the microstructure and properties of the laser cladding Ni-based alloy coatings,Ni25,Ni45,Ni60 alloy coatings were fabricated on the substrate of 45# steel by laser cladding of the corresponding Ni-based self-fluxing alloy powders at the same process parameters.The microstructure,phase composition and microhardness have been analyzed by the scanning electron microscopy（SEM）,X-ray diffractometry（XRD）,energy dispersive X-ray spectroscopy（EDS） and microhardness meaurement,respectively.The results show that with increasing alloying element contents,the microstructure of coatings changes from the hypoeutectic to hypereutectic structure,the volume fraction and the size of γ-Ni austenite dendrites and the width of bonding zone between the coating and substrate decrease,but the volume fraction of the interdendritic eutectics and hard phases and the microhardness of the coatings increase from the laser cladding Ni25 to Ni60 alloy coatings.The average microhardness of the laser cladding Ni25,Ni45 alloy coatings are about 250 HV and 550 HV,respectively.However,the average microhardness of the Ni60 alloy coating is about up to 750 HV.It is three times that of the Ni25 alloy coating.

关 键 词：激光熔覆 镍基合金 涂层 结合带 显微硬度 

分 类 号：TG174.44[金属学及工艺—金属表面处理]