5083铝合金表面钛铝基耐蚀涂层与TA2钛合金接触腐蚀

Galvanic Corrosion Between TiAl-Based Corrosion-resistance Coating on 5083 Aluminum Alloy and TA2 Titanium Alloy

针对5083铝合金与TA2钛合金接触腐蚀问题,采用超音速微粒沉积技术在5083铝合金表面制备Ti-45Al-7Nb-4Cr耐蚀涂层,采用扫描电子显微镜(SEM)和能谱仪(EDS)对涂层截面和与基体界面进行测试,分析涂层孔隙率和与5083铝合金基体的结合机制;采用电化学工作站测试5083铝合金、TA2钛合金、TiAl合金铸锭和涂层的极化曲线,并对比研究5083铝合金、TiAl合金铸锭和涂层与TA2钛合金接触腐蚀敏感性。结果表明:涂层孔隙率为1.4%,涂层与基体结合机制为机械结合,通过在5083铝合金表面制备Ti-45Al-7Nb-4Cr合金防护涂层后,可使材料电极电位由-913.90mV升高到-572.47mV,与TA2钛合金的接触腐蚀电流密度由16.2μA/cm2降为0.21μA/cm2,接触腐蚀敏感性由E级降到A级,解决了铝合金与钛合金的接触腐蚀防护问题。

To solve the galvanic corrosion problem between 5083 aluminum alloy and TA2 titanium alloy,Ti-45Al-7Nb-4Cr corrosion-resistance coating was prepared on 5083 aluminum alloy surface through supersonic particle deposition technology.The coating section and interface morphology were observed to analyze porosity and combining mechanism by scanning electron microscopy（SEM）and energy disperisve spectrometer（EDS）.The polarization curves of 5083 aluminum alloy,TA2 titanium,titanium aluminum ingot and coating was tested by electrochemical workstation.The galvanic corrosion sensitivity of TiAl coating and TA2 titanium was studied.The results show that the coating porosity is 1.4%,and the combining mechanism between the coating and the substrate is mechanical bond.The prepared Ti-45Al-7Nb-4Cr corrosion coating on 5083 aluminum alloy surface can make the electrode potential improve from-913.90 mV to-572.47 mV,the galvanic corrosion current between the coating and TA2 titanium decrease from 16.2μA/cm^2 to 0.21μA/cm^2,and the galvanic corrosion sensitivity decrease from E to A.The protection problems of galvanic corrosion between aluminum alloy and titanium alloy are resolved.