掺杂Ni/Al对热障涂层抗高温氧化性和结合强度的影响

Influence of Ni/Al Doping on the High Temperature Oxidation Resistance and Bonding Strength of Thermal Barrier Coatings

YSZ(Ni,Al)粉末颗粒通过电泳沉积技术在高温镍基合金600上沉积一层厚度均匀的YSZ(Ni,Al)复合热障涂层,并在室温下干燥24 h后,进行真空烧结致密化处理。真空致密化处理后的YSZ(Ni,Al)复合热障涂层在1100℃下氧化不同小时并测量涂层的结合强度。由于掺杂了镍铝氧化初期在涂层表面形成一层致密的氧化薄膜,有效地阻止了空气中的氧气进一步进入涂层内部从而提高了涂层的抗高温氧化性能,另外在陶瓷涂层YSZ中掺杂了金属元素,降低了陶瓷涂层与高温镍基合金的热膨胀系数的不匹配,使涂层表面更加平整致密,同时也提高了涂层与基体的结合强度。

YSZ（Ni, Al） powder particles were deposited on nickel-based alloy 600 to a layer of uniform thickness by electrophoretic deposition technique, and after dried for 24 h at room temperature, vacuum sintering densification process is following. YSZ （Ni, AI） composite thermal barrier coatings of vacuum sintering densification process oxidized at 1100 ℃ in different time and measure the bonding strength. Owing to doping Ni-Al, a layer of dense oxide film formed at the initial oxidized time, and effectively prevent the oxygen in the air further into the interior of coating to improve the high temperature oxidation resistance of the coating. What＇s more, doped metal element in the YSZ ceramic coating can reduce the mismatch of the thermal expansion coefficient of ceramic coating and high temperature nickel-based alloys to make the surface of thermal barrier coatings more smooth and compact, at the same time, the bonding strength of the coating and the substrate was enhanced.