ZK60镁合金激光表面熔凝处理及性能研究  

Study on laser surface melting treatment and properties of ZK60 magnesium alloy

作　　者：张玺 韩峰[1,2] 闫基森 解芳[1,2] 武冰冰 刘刚 Zhang Xi;Han feng;Yan Jisen;Xie Fang;Wu Bingbing;Liu Gang(Engineering Research Center of Additive Manufacturing Aeronautical Materials of Henan Province,Nanyang Institute of Technology,Nanyang 473004,China;Nanyang Key Laboratory of Additive Manufacturing Technology and Equipment,Nanyang Institute of Technology,Nanyang 473004,China)

机构地区：[1]南阳理工学院河南省增材制造航空材料工程研究中心,河南南阳473004 [2]南阳理工学院南阳市增材制造技术与装备重点实验室,河南南阳473004

出　　处：《电镀与精饰》2023年第7期61-67,共7页Plating & Finishing

基　　金：国家自然科学基金(51605230);河南省重点研发与推广专项(科技攻关)(222102240002和232102221022);南阳理工学院交叉科学研究项目(520064)。

摘　　要：为提高ZK60镁合金的耐腐蚀性能,采用激光表面熔凝的方法在镁合金表面制备激光熔凝层,研究扫描速度对镁合金熔凝层形貌、微观组织、显微硬度及耐腐蚀性能的影响。采用光学显微镜、X射线衍射仪等仪器,观察分析熔凝层的表面及横截面形貌、粗糙度和显微组织,采用显微维氏硬度计测试分析熔凝层横截面的显微硬度,采用电化学工作站测试分析熔凝层的耐腐蚀性能。结果表明,激光表面熔凝处理在镁合金表面形成了厚度约为100~180μm的熔凝层,熔凝层厚度和表面粗糙度随扫描速度的降低而增加。熔凝层由细小等轴晶和放射状柱状晶组成,晶粒尺寸约1.5μm,熔凝层的相组成为α-Mg相和MgZn_(2)相,显微硬度比基体提高了约33.7%。当扫描速度为25 mm/s时,镁合金熔凝层的自腐蚀电位比未处理镁合金向正向移动了0.118 V,自腐蚀电流密度比未处理镁合金降低了约2个数量级,耐腐蚀性达到最佳。In order to improve the corrosion resistance of ZK60 magnesium alloy,laser melted layer was prepared on the surface of magnesium alloy by laser surface melting treatment.The effects of scanning speed on the morphology,microstructure,microhardness and corrosion resistance of melted layer of magnesium alloy were investigated.The surface and cross section morphology,roughness and microstructure of the melted layer were observed and analyzed by optical microscope and X-ray diffractometer.The microhardness of the cross section of the melted layer was measured and analyzed by micro Vickers hardness tester,and the corrosion resistance of the melted layer was analyzed by electrochemical workstation.The results show that the laser surface melted layers with thickness of 100−180μm are formed on the magnesium alloy surface.The thickness and surface roughness of melted layer increase with the decrease of scanning speed.The melted layer is composed of fine equiaxed crystals and radial columnar crystals with a grain size of about 1.5μm.The microstructure of the melted layer consists ofα-Mg phase and MgZn_(2) phase,and its microhardness is 33.7%higher than that of the matrix.When the scanning speed is 25 mm/s,the corrosion resistance of the melted layer reaches the best.The selfcorrosion potential of the melted layer moves 0.118 V forward compared with untreated magnesium alloy,and the self-corrosion current density decreases by about 2 orders of magnitude compared with untreated magnesium alloy.

关 键 词：ZK60镁合金 激光表面熔凝 扫描速度 耐腐蚀性 

分 类 号：TG178[金属学及工艺—金属表面处理]