高温合金上AlON/Al2O3复合绝缘层的制备及绝缘性能研究

Fabrication and high temperature electrical insulation property of AlON/Al2O3 composite coating on superalloy substrate

为了提高镍基高温合金基底的高温电绝缘性能,改善航空发动机工作过程中温度传感器的可靠性问题,采用直流反应溅射的方法溅射非晶AlON薄膜,将电子束蒸发沉积的Al2O3薄膜作为保护层,制备了AlON/Al2O3复合绝缘层。通过XRD、SEM表征对制备的非晶AlON薄膜进行微结构分析,并对AlON/Al2O3复合绝缘层进行高温绝缘性能测试。结果显示,制备的复合绝缘层具有良好的高温绝缘性,800℃时绝缘电阻达到5.6 MΩ,1000℃达到140 kΩ,相对于单一Al2O3绝缘层的绝缘电阻提升了三个数量级。复合绝缘层制备在溅射过程中一次性完成,显著提升了绝缘层的质量和制备效率,为与高温合金衬底一体化集成的薄膜热电偶可靠工作奠定了基础。

In order to improve high-temperature electrical insulation of the nickel-based superalloy substrate and improve the reliability of the temperature sensor during the operation of the aero-engine,the amorphous AlON film and the Al2O3 film was sputtered by the DC reactive sputtering,to form the AlON/Al2O3 composite coating.The microstructure of the prepared AlON film was analyzed by XRD and SEM,and the high temperature insulation property of the AlON/Al2O3 composite insulating layer was measured.The results show that the prepared composite coating has good high-temperature insulation property.The resistance reaches 5.6 MΩat 800℃and 140 kΩat 1000℃,which is three orders of magnitude higher than that of the single Al2O3 insulation layer.The preparation of the composite coating is completed at one time during the sputtering process,which significantly improves the quality and preparation efficiency of the insulating layer.This work provides foundation for the reliable operation of the thin film thermocouple on the superalloy substrate.