镍基合金激光熔覆层微观组织特征及强化机制研究  

Microstructure characteristics and strengthening mechanisms of Ni-based alloy coating by laser cladding

作　　者：袁庆龙[1] 冯旭东[1] 曹晶晶[1] 苏志俊[1] 

机构地区：[1]河南理工大学材料科学与工程学院,河南焦作454000

出　　处：《河南理工大学学报（自然科学版）》2010年第2期245-248,共4页Journal of Henan Polytechnic University（Natural Science）

基　　金：山西省回国留学人员科研资助计划项目(2007-34)

摘　　要：采用粘接预置法在Q235低碳钢表面预置了Ni60涂层,然后对其进行激光重熔处理,通过金相法和硬度测试分析涂层的组织特征与强化机制.结果表明,激光熔覆层组织组成物主要包括γ-Ni固溶体,碳化物,硼化物,硅化物+γ-固溶体的共晶体以及初晶合金渗碳体和共晶合金渗碳体等金属间化合物.在界面处形成了一条白亮带,在熔覆层底部,形成了胞状晶和胞状枝晶,在熔覆层中上部,形成了细小的等轴晶.通过固溶强化、弥散共晶强化、硬质相强化、细晶强化和位错强化5种强化机制,使熔覆层达到了表面强化的目的.Ni60 coating formed on the surface of lower-carbon steel was prepared by pre-bonding method,and then it was laser cladded,and the characteristics of the microstructure and the strengthening mechanism of Ni60 coating were analyzed by metallographic method and hardness testing.The results show that the laser cladded layer is consisted of γ-Ni solid solution,carbide,boride,silicide ＋γ-solid solution eutectic and intermetallic compounds such as primary alloy cementite and cementite alloy eutectic.It forms a banded structure in the interface of the layer,at the bottom of the coating,cellular crystal and cellular dendritic are formed,in the upper cladding layer,small equiaxed grains are formed.It reaches the purpose of the strengthening the surface through five strengthening mechanisms of solution strengthening,eutectic dispersion strengthening,hard phase strengthening,refined crystalline strengthening and the dislocation strengthening.

关 键 词：激光熔覆 镍基合金 微观组织 强化机制 

分 类 号：TG174.44[金属学及工艺—金属表面处理]