Nb-Hf 合金表面Si-Ti-Cr硅化物涂层在恒温氧化和热震中的高温抗氧化性能

High-Temperature Oxidation Resistance Performance of Si-Ti-Cr Silicide Coating on Nb-Hf Alloy Surface in Constant Oxidation and Thermal Shock

摘要:

为了提高Nb-Hf 合金的高温抗氧化性能，采用浆料烧结和高温渗透制备了Si-Ti-Cr硅化物涂层。分析了Si-Ti-Cr 硅化物包覆的Nb-Hf 合金样品在恒温氧化和高温热震条件下的抗氧化性能，揭示了Si-Ti-Cr 涂层高温恒温氧化和高温热震条件下的失效机理。结果表明，在1800 ℃恒温氧化5 h条件下，涂层的增重为7 mg/cm²；在1700 ℃热震循环50周次和恒温氧化5 h条件下，涂层的最大增重为1.8 mg/cm²。硅化物涂层在1800 ℃恒温氧化环境下和1700 ℃热震/恒温氧化环境下具有优异的抗氧化性能。

Abstract:

To improve the high-temperature oxidation resistance performance of Nb-Hf alloys, Si-Ti-Cr silicide coatings were prepared on Nb-Hf alloy by slurry sintering and high-temperature permeation methods. The high-temperature oxidation resistance performance of Si-Ti-Cr silicide coating on Nb-Hf alloys in high-temperature constant oxidation and high-temperature thermal shock was analyzed, and the failure mechanism of Si-Ti-Cr coating in high-temperature constant oxidation and high-temperature thermal shock was determined. The results show that the mass gain of the coating is 7 mg/cm² after constant oxidation at 1800 °C for 5 h. The mass gain of the coating in atmosphere is less than 1.8 mg/cm² after thermal shock cycles for 50 cycles followed by constant oxidation at 1700 °C for 5 h. Therefore, the silicide coating exhibits excellent oxidation resistance at 1800 °C in constant oxidation and at 1700 °C in thermal shock/constant oxidation.