H2对电弧等离子体炬制备8YSZ涂层的影响

Effect of H2 on 8YSZ Coatings Prepared by Arc Plasma Torch

摘要:

使用8YSZ颗粒喷涂技术制备热障涂层（TBCs），通常会在等离子体炬放电气体中加入H₂。通过改变工作气体中H₂含量，研究H₂对放电产生的影响，同时结合粒子速度捕获诊断、光学发射光谱仪和有限元模拟，验证H₂含量与涂层质量之间的联系。结果表明：添加H₂会提高等离子体温度和速度，从而提高熔融8YSZ颗粒的效率和飞行速度。然而，将H₂/(Ar+H₂)的值提高到50%，电弧根部的不稳定性影响电弧等离子体放电，这使得保持飞行粒子的物理状态变得具有挑战性。随着H₂流速的升高，涂层质量呈现先上升后下降的趋势，最佳流速比为H₂/(Ar+H₂)=37.5%。该研究结果可以为等离子体制备TBCs提供理论指导。

Abstract:

The thermal barrier coatings (TBCs) are prepared using spraying technique of 8YSZ particles. In this process, H₂ is often added to the plasma torch discharge system. In order to study the effect of H₂ content on plasma discharge, this study emplyed particle velocity capture diagnostics, optical emission spectroscopy, and finite element simulation to validate the relationship between H₂ content and coating quality. The results indicate that adding H₂ increases the temperature and velocity of plasma, which in turn improves the efficiency and in-flight velocity of molten 8YSZ particles. However, when the H₂ /(Ar+H₂) is increased to 50%, the instability of arc root disturbs the arc plasma discharge, posing a challenge to maintaining the physical state of the in-flight particles. With an increase in H₂ flow rate, the coating quality shows a trend of first increasing and then decreasing, with the optimal flow rate ratio being H₂/(Ar+H₂)=37.5%. The findings of this work can serve as a theoretical guidance and reference for the preparation of TBCs via plasma.