材料期刊网

采用电弧离子镀在g-TiAl基体上镀铝后进行扩散处理制备出了扩散铝涂层，涂层与基体结合良好。EDX和XRD分析表明涂层由很厚的TiAl3外层和较薄的TiAl2内层构成。900oC空气中的恒温氧化试验结果显示，g-TiAl氧化后生成了疏松多层的Ti和Al氧化物的混合物，其抗高温氧化性能很差，施加扩散铝涂层后，高温下生成了一层连续致密的Al2O3膜，抗氧化性能显著提高。讨论了涂层的氧化和退化机制。

Al diffusion coatings were prepared on g-TiAl alloy by first arc ion plant Al then interdiffusion treatment processes. Al diffusion coatings have a good adherence with the substrate, and EDX and XRD show that the coatings composed of outer thick layer TiAl3 and inner thin layer TiAl2. For g-TiAl without coating under high temperature oxidation at 900oC in air, multilayer oxide scale is formed and consisted of mix of TiO2 and Al2O3, which exhibits relatively poor oxidation resistance. The high temperature oxidation resistance of the specimens coated with Al diffusion coatings is remarkably improved due to the formation of a dense and adherent Al2O3 scale. The oxidation and degradation mechanism of Al diffusion coatings also are discussed.