TiAl涂层对Ti_3Al合金腐蚀行为的影响

Effects of TiAl Coating on Hot Corrosion and Electrochemical Corrosion of Ti_3Al Alloy

利用磁控溅射的方法在Ti3Al合金上溅射Ti-48Al-8Cr-2Ag(原子分数/%)涂层,研究涂层对Ti3Al合金熔盐热腐蚀和电化学腐蚀行为的影响。同时通过TEM,SEM,EDX,电化学工作站对合金的腐蚀进行研究,并对腐蚀机理进行探讨。结果表明:在熔盐热腐蚀中,涂层对基体具有很好的防护作用,这主要是因为Ti3Al合金表面发生了大面积的脱落,而涂层试样表面腐蚀膜结合牢固。经过电化学腐蚀研究,涂层试样表面发生明显的分级钝化现象,表明涂层在Na2SO4+K2SO4溶液中具有很好的钝化性能,显示了很好的抗电化学腐蚀性能。

Magnetron-sputter deposition was used to produce a Ti-48Al-8Cr-2Ag （atom fraction/%） coating on a cast Ti3 Al alloy substrate. The corrosion microstructures were analyzed in great detail by scanning electron microscopy （SEM）,energy dispersive X-ray diffraction （EDX） and transmitted electron microscopy （TEM） investigations. The results indicated that the sputtered coating showed much better hot corrosion resistance in molten （Na,K）2SO4 than that of Ti3Al substrate. In electrochemical corrosion, the coating exhibited the passivation phemonenon, and showed the excellent electrochemical corrosion resistance.