阴极微弧放电制备TiAl合金表面Al_2O_3膜的高温氧化性能

High Temperature Oxidation Properties of Al_2O_3 Coating on TiAl Alloy Fabricated by Cathodic Microarc Deposition Method

在Al(NO3)3溶液中利用阴极微弧放电沉积方法,制备了TiAl合金表面的Al2O3膜,膜的厚度为80μm。空气环境下,在900℃下进行高温氧化实验。利用扫描电镜(SEM)和X射线衍射(XRD)分析了样品在高温氧化前后的形貌和物相变化。100h高温氧化后,Al2O3膜保持完整,与基体有较好的结合。高温氧化前后物相均为γ-Al2O3和少量的α-Al2O3,但是氧化后的膜层中出现了少量的Rutile-TiO2。阴极微弧沉积方法在TiAl合金表面制备的Al2O3膜能够有效地提高基体在900℃时的抗氧化性能。

A Al2O3 coating with the thickness of 80μm was prepared on the surface of TiAl alloy in Al（NO3）3 electrolyte by cathodic microarc deposition technology.The isothermal oxidation test was performed under 900℃ in atmosphere environment.Before and after high temperature oxidation,the morphology,microstructure and phase constitutions of the coating were detected by X-ray diffraction（XRD）,energy dispersive spectroscopy（EDS） and scanning electron microscopy（SEM）.After isothermal oxidation,the coating was intact and adhesive well to the substrate.The mainly constitutions of prepared coating were γ-Al2O3 and a small amount of γ-Al2O3.In addition,amount of Rutile-TiO2 was detected in the coating after oxidation test.The anti-oxidation property of TiAl alloy was improved obviously by as prepared Al2O3 coating at 900℃.