TiAl合金微弧氧化陶瓷层高温特性的研究

Anti Oxidation Ability of Micro Arc Oxidation Coating on TiAl Alloy at Elevated Temperature

为提高TiAl合金的抗高温氧化性能 ,采用微弧氧化技术 ,对TiAl合金表面生成的微弧氧化陶瓷层在高温循环氧化条件下的氧化动力学进行了研究。结果表明 ,经过微弧氧化处理试样的高温氧化动力学曲线呈抛物线规律 ,其表面的陶瓷氧化膜具有保护性 ;微弧氧化后TiAl合金的使用温度可提高到 10 0 0℃ ;微弧氧化陶瓷层中的SiO2 能有效抑制Al2 TiO5在高温下的分解 。

Micro arc oxidation coating was prepared on the surface of TiAl alloy so as to increase its anti oxidation ability at elevated temperature. The oxidation dynamics of the micro arc oxidation ceramic layer subject to cyclic oxidation at elevated temperature were investigated. It was found that the oxidation dynamics curves of the micro arc oxidized TiAl alloy at elevated temperature were parabola shaped, which indicated that the micro arc oxidation ceramic layer was able to protect the TiAl alloy substrate from oxidation at elevated temperature. Namely, the SiO^(2-)_3 ions in the micro arc oxidation ceramic coating were capable of retarding the decomposition of Al_2TiO_5 at elevated temperature, which contributed to significantly increase the anti oxidation ability of the TiAl alloy. Subsequently, the TiAl alloy after the micro arc oxidation treatment could be used up to 1 000 ℃.