AZ31B镁合金表面激光熔覆Ni60合金粉末组织及性能  

Study on Laser Cladding of Ni60 Alloy Coating on AZ31B Magnesium Alloy

作　　者：崔泽琴[1,2] 王文先[1,2] 葛亚琼[2] 许并社[1,2] 

机构地区：[1]新材料界面科学与工程教育部重点实验室(太原理工大学),太原030024 [2]太原理工大学材料科学与工程学院,太原030024

出　　处：《材料工程》2009年第S1期163-166,171,共5页Journal of Materials Engineering

基　　金：山西省自然科学基金(2008011044)

摘　　要：利用5kW横流连续CO2激光器,采用预置粉末法对AZ31B镁合金表面进行激光熔覆Ni60合金粉末试验。利用光学显微镜,SEM,XRD,显微硬度仪,电化学腐蚀设备等仪器对熔覆层和基体的组织及性能进行了测试分析。结果表明,熔覆层与基体呈冶金结合,熔覆层组织为细小的树枝晶和等轴晶;XRD结果表明在熔覆层表面形成了Mg2Ni,Mg-Ni2等新相,熔覆层的显微硬度由HV45~50提高到HV150~350,约为基体的3~7倍。在3.5%(质量分数)NaCl的溶液中进行电化学腐蚀试验表明,熔覆层表面的自腐蚀电位较原始镁合金提高约0.379V,其抗腐蚀性较原始镁合金显著提高。Laser cladding of Ni60 alloy coating on AZ31B magnesium alloy was achieved by using a 5kW continuous wave CO2 laser remelting of replaced-powder.The microstructure and properties of cladding sample was carried out by means of OM,SEM,micro-hardness equipment,and electrochemical corrosion equipment etc.The results show that the cladding layer connected well with the substrate.The cladding layer appears a great deal of fine equal axialite and dendritic grains and forms Mg2Ni,MgNi2 and MgNiO2 phase etc.Micro-hardness of the laser cladding melted layer was improved to HV150-350 as compared to HV45-50 of the as-received AZ31B.The results of electrochemical corrosion show that the corrosion resistance of laser cladding Ni60 alloy has been improved compared to the untreated AZ31B substrate.The potentiodynamic polarization test results confirmed that the corrosion resistance of the coating is obviously improved and the corrosion potential of laser cladding layer is increased by 0.379V than the untreated AZ31B substrate in 3.5%(mass fraction) NaCl solution.

关 键 词：AZ31B镁合金 激光表面熔覆 Ni60合金粉末 

分 类 号：TG174.4[金属学及工艺—金属表面处理]