激光熔凝前处理对钛合金表面电沉积铜过程及耐蚀性的影响

Effect of Laser Melting Pretreatment on Process and Corrosion Resistance of Electrodeposited Copper on Titanium Alloy Surface

目的通过激光前处理提高钛合金表面铜沉积层的质量及性能。方法采用振镜激光器在电沉积铜前对钛合金基体表面先进行激光熔凝处理,整个熔凝过程在气氛保护下进行。研究了激光熔凝前处理对沉积层与基体结合力的影响机理,对传统化学前处理与激光熔凝前处理后铜沉积过程中的微观形貌、截面厚度、沉积层结合力和耐腐蚀性能进行了对比分析。结果采用激光熔凝前处理后,钛合金表层组织得到细化并产生大量位错,从而削弱了沉积初期的选择性,表面沉积速率更快,获得的沉积层厚度更大,沉积层孔隙更少、更致密。1 h相同沉积时间下,激光熔凝前处理的沉积层厚度为163.65μm,几乎达到化学前处理得到的沉积层厚度(97.97μm)的两倍,且沉积层表现出与基体更佳的结合力。耐蚀性测试得到化学前处理与激光前处理所得铜沉积层的腐蚀电压分别为‒0.441、‒0.393 V,腐蚀电流密度分别为55.18、5.913μA/cm^(2)。结论激光熔凝前处理提高了钛合金表面铜沉积层的沉积质量及其与基体间的结合力,同时提高了铜沉积层的耐腐蚀性能。

To improve the quality and performance of copper deposits on the surface of titanium alloys through laser pretreatment,in this paper,a galvanometer laser was used to perform laser melting pretreatment on the superficial layer of the titanium alloy substrate before electrodepositing copper.The whole laser melting process was under the protection of atmosphere.The effect mechanism of laser melting pretreatment on the bond between the deposited layer and the substrate was studied.The morphology,cross-sectional thickness,bonding force and corrosion resistance of the copper deposition after traditional chemical pretreatment and laser melting were compared and analyzed.The results showed that the surface microstructure of the titanium alloy was refined,a large number of dislocations were generated after the pretreatment of laser melting,which weakened the selectivity of the initial deposition and improved the deposition rate.The electrodeposited layer was thicker,with fewer pores and more dense after laser melting pretreatment.At the same deposition time for 1 h,the thickness of the electrodeposited layer obtained by the laser melting pretreatment sample was 163.65μm,which was almost twice that of the chemical pretreatment sample(97.97μm).In addition,the electrodeposited copper layer of the laser melting pretreatment sample showed better bonding force with the substrate.The corrosion resistance test showed that the corrosion voltages of the copper deposits obtained by chemical pretreatment and laser pretreatment were‒0.441 V and‒0.393 V,and the corrosion current densities were 55.18μA/cm^(2) and 5.913μA/cm^(2),respectively.Laser melting pretreatment improved the deposition quality of the copper deposition layer on the surface of the titanium alloy and the bonding force with the substrate,and at the same time improved the corrosion resistance of the copper deposition.