Al-Ti-Si-RE涂层在模拟深海压力下的耐蚀机理  

Anti-corrosion Mechanism of Al-Ti-Si-RE Coating in the Pressure Environment of Simulated Deep Sea

作　　者：童辉[1,2] 魏世丞[2] 刘毅[2] 王新坤[2] 刘文超[2] 徐滨士[2] Tong Hui Wei Shicheng Liu Yi Wang Xinkun Liu Wenchao Xu Binshi(Beijing University of Technology, Beijing 100124, China National Key Laboratory for Remanufacturing, Academy of Armored Forces Engineering, Beijing 100072, China)

机构地区：[1]北京工业大学,北京100124 [2]装甲兵工程学院装备再制造技术国防科技重点实验室,北京100072

出　　处：《稀有金属材料与工程》2016年第11期2918-2924,共7页Rare Metal Materials and Engineering

基　　金：国家自然科学基金项目(51222510);国家重点基础研究发展计划("973"计划)(2011CB013403);国家高技术研究发展计划("863"计划)(2013AA040203)

摘　　要：通过电化学测试技术与微观分析等手段研究了高速电弧喷涂Al-Ti-Si-RE涂层在模拟深海压力下的耐蚀机理。结果表明：Al-Ti-Si-RE涂层在静水压力条件下具有良好的耐蚀性能。电化学分析表明,在3 MPa浸泡480 h后动电位极化曲线阳极区上出现了1个类似钝化区间的＂平台＂,主要是由于腐蚀产物阻塞腐蚀通道的原因;电化学阻抗谱（EIS）分析则表明,在高压下涂层Al钝化膜在浸泡6 h左右后已溶解,12 h后逐步趋于稳定,300~480 h区间几乎无变化;电化学噪声（EN）测试对比了涂层在常压和高压条件下0~64 ks的腐蚀情况,定量描述了涂层＂钝化膜溶解-腐蚀产物快速形成-进入稳定阶段＂的腐蚀过程。最后通过微观形貌观察和XRD等测试手段分析,Al-Ti-Si-RE涂层中的富Ti相（主要成分为TiAl、TiAl3等金属间化合物）具有良好的耐蚀特性,且呈现为多孔结构,Al在高压下快速腐蚀溶解填充富Ti相＂骨架＂孔隙,形成的涂层表面致密,其结构能够有效阻塞腐蚀通道,抑制腐蚀进行。The anticorrosion mechanism of Al-Ti-Si-RE coating in the environment of simulated deep sea was investigated using electrochemical measurement and micro-analysis. The result shows that Al-Ti-Si-RE coating possesses better corrosion resistance at hydrostatic pressure than at atmospheric pressure. After 480 h immersion at 3 MPa, a platform similar to a passivation region occurs in the anode of the potentiodynamic polarization curve because corrosion products block the corrosion channels. At the same time, at hydrostatic pressure, electrochemical impedance spectroscopy（EIS） indicates that Al passive film dissolves within 6 h of immersion, then tends to be stable after 12 h, and hardly changes between 300 and 480 h. To further analyze the original corrosion process, electrochemical noise（EN） of 0~64 ks at 0.1 and 3 MPa was measured, which quantificationally described the corrosion process from passive film dissolving to corrosion product fast-forming to stabilization. From morphology observation and X-ray diffraction（XRD） analysis, the rich Ti phase（Ti-Al intermetallics, etc） of the coating is cellular and has good corrosion resistance, whose construction could fix the Al oxide inside the coating, and thicken the coating to inhibit the corrosion.

关 键 词：高速电弧喷涂 涂层 深海腐蚀 电化学测试 微观分析 

分 类 号：TG174.4[金属学及工艺—金属表面处理]