无氰镉钛镀液中钛离子浓度对镀层性能的影响  

Effect of titanium ion concentration in cyanide-cadmium-free titanium plating solutions on coating properties

作　　者：李旭勇 李琼 魏娜 李燕平 廖可 王云飞 王春霞[2] Li Xuyong;Li Qiong;Wei Na;Li Yanping;Liao Ke;Wang Yunfei;Wang Chunxia(AVIC Jiangxi Hongdu Aviation Industry Group Co.,Ltd.,Nanchang 330063,China;College of Materials Science and Engineering,Nanchang Aviation University,Nanchang 330063,China)

机构地区：[1]中航工业洪都航空工业集团有限责任公司,江西南昌330063 [2]南昌航空大学材料科学与工程学院,江西南昌330063

出　　处：《电镀与精饰》2023年第12期15-24,共10页Plating & Finishing

摘　　要：研究无氰镉钛镀液中钛离子含量变化对其中金属的电结晶行为、镀层组织结构、耐蚀性以及渗氢特性的影响。通过阴极极化曲线、阶跃计时电流曲线分析无氰镉钛电沉积过程及形核方式;采用模拟海水浸泡实验,利用交流阻抗和塔菲尔曲线分析镉钛合金镀层耐蚀性;利用X射线衍射仪研究镀层晶体结构的择优取向变化;通过SEM观察了镀层微观形貌;通过渗氢实验测试分析镉钛镀层对阻挡还原氢渗透能力的影响。镀液钛离子浓度的增加,金属的沉积电位和析氢电位负移,镉钛沉积由连续形核转变为瞬时形核,镀层的整平性和组织的均一性也随之增加,择优取向由(101)晶面转向(110)晶面。镀液中钛离子浓度增加时,镀层的自腐蚀电流密度有略微上升的趋势,但均在10-6数量级。镀层的防渗氢性能随钛离子浓度增加而有所下降。镀液中钛离子浓度在2~3 g/L范围内时,所得镀层的耐蚀性及阻止还原氢渗透的能力较好。This work aims to investigate the effects of the change of titanium ion content in cyanide-cadmium-free titanium plating solution on the electrocrystallization behavior,coating microstructure,corrosion resistance and hydrogen permeation characteristics of the metal.Analysis of cyanide-free cadmium-free titanium electrodeposition process and nucleation mode by cathodic polarization curve and step timing current curve.Simulated seawater immersion experiment was used to analyze the corrosion resistance of cadmium titanium alloy coating using AC impedance and Tafel curves.X-ray diffractometer was used to study the optimal orientation change of coating crystal structure.The microscopic morphology of coating was observed by SEM.The effect of cadmium and titanium coating on the ability to block reduced hydrogen permeability was analyzed by hydrogen permeation experimental test.The concentration of titanium ions in the plating solution increases,the deposition potential of the metal and the negative shift of the hydrogen evolution potential,the cadmium titanium deposition changes from a continuous-shaped nucleus to an instantaneous nucleus,and the uniformity of the plating layer also increases,and the optimal orientation shifts from(101)crystal plane to(110)crystal plane.When the concentration of titanium ions in the plating solution increases,the self-corrosion current density of the coating has a slight upward trend,but it is in the order of 10-6.The hydrogen impermeability of the coating decreases with the increase of titanium ion concentration.When the concentration of titanium ions in the plating solution is in the range of 2-3 g/L,the corrosion resistance of the resulting coating and the ability to prevent the penetration of reduced hydrogen are better.

关 键 词：无氰电镀镉钛 钛离子浓度 形核 微观形貌 耐蚀性 渗氢 

分 类 号：TG174.4[金属学及工艺—金属表面处理]