基于正交试验的WE43镁合金化学膜转化法工艺优化  

Process Optimization of Chemical Coating Conversion Method for WE43 Magnesium Alloy Based on Orthogonal Experiment

作　　者：刘曜熙 陈乐平[1] 周全[1] 袁源平 刘武平 Liu Yaoxi;Chen Leping;Zhou Quan;Yuan Yuanping;Liu Wuping(School of Aeronautical Manufacturing Engineering,Nanchang Hangkong University)

机构地区：[1]南昌航空大学航空制造工程学院,南昌330063

出　　处：《特种铸造及有色合金》2023年第9期1235-1239,共5页Special Casting & Nonferrous Alloys

基　　金：江西省科技重点研发计划资助项目(20212BBE53018);南昌航空大学研究生创新专项基金资助项目(YC2022-018)。

摘　　要：采用高锰酸钾点滴试验、动电位极化曲线、扫描电镜(SEM/EDS)、X射线衍射(XRD)等测试方法,通过调整磷化液成分、温度、磷化时间及pH值参数,开展4因素3水平正交试验以优化磷化工艺参数,研究了磷化膜的腐蚀行为,同时探讨了成膜机理。结果表明,当氟化钠浓度为2.38×10^(-2)mol/L,磷化时间为30 min、温度为65℃、pH值为3.2时,制备的磷化膜表面均匀致密,厚度约为12.63μm,其主要成分为Zn_(3)(PO_(4))_(2)和Zn_(2)Mg(PO_(4))_(2)。磷化膜的形成可以有效降低WE43镁合金的腐蚀倾向,腐蚀电流密度由未处理的4.611×10^(-5)A/cm^(2)下降至2.859×10^(-5)A/cm^(2),降低了38%;腐蚀速率由未处理的1.01 mm/a下降至0.62 mm/a,降低了38.61%,故磷化处理可以提高WE43镁合金的耐蚀性。Potassium permanganate drop test,potentiodynamic polarization curve,scanning electron microscopy(SEM/EDS),X-ray diffraction(XRD)and other test methods were applied.By adjusting the phosphating solution composition,temperature,phosphating time and pH value,four factors and three levels orthogonal experiments were carried out to optimize the phosphating process parameters.The corrosion behavior of phosphating film was analyzed,and the film formation mechanism was explored.The results reveal that with the sodium fluoride concentration of 2.38×10^(-2)mol/L,the phosphating time of 30 min,the temperature of 65℃and the pH value of 3.2,the surface of prepared phosphating film presents uniform and dense,and the thickness is about 12.63μm with the main components of Zns(PO_(4))_(2)and Znz Mg(PO_(4))_(2).The formation of phosphating film can effectively reduce the corrosion tendency of WE43 magnesium alloy.The corrosion current density is decreased from 4.611×10^(-5)A/cm^(2)to 2.859×10^(-5)A/cm^(2),which is reduced by 38%.The corrosion rate is decreased from 1.01 mm/a to 0.62 mm/a,which is reduced by 38.61%,indicating phosphating can improve the corrosion resistance of WE43 magnesium alloy.

关 键 词：WE43镁合金 磷化处理 锌系磷化膜 耐蚀性能 

分 类 号：TG178[金属学及工艺—金属表面处理] TG146.22[金属学及工艺—金属学]