喷涂轨迹对铝合金表面等离子喷涂Mo/8YSZ功能梯度热障涂层温度场的影响规律研究

为了突破传统Mo/8YSZ双层热障涂层高温易剥离的技术瓶颈,研究喷涂轨迹对等离子喷涂功能梯度热障涂层温度场的影响规律,利用ANSYS有限元仿真模拟软件,基于"生死单元"的方法,建立了等离子喷涂功能梯度热障涂层的有限元模型,模型中考虑了材料的相变潜热及不同温度下的热物性参数,分析了不同喷涂轨迹下喷涂构件温度及温度梯度的分布情况。结果表明:当喷涂粘结层和过渡层材料时,采用同向的喷涂轨迹时,喷涂构件的温度最高;采用同种材料同向喷涂,异种材料喷涂方向相反的喷涂轨迹时,喷涂构件的温度次之;采用"S"型的喷涂轨迹时,喷涂构件温度最低。当喷涂陶瓷层材料时,采用"S"型的喷涂轨迹时,喷涂构件的温度最高;采用同向的喷涂轨迹时,喷涂构件的温度次之;而采用同种材料同向喷涂,异种材料喷涂方向相反的喷涂轨迹时,喷涂构件的温度最低。采用"S"型喷涂轨迹进行喷涂作业时,喷涂构件左右两端面温度分布的均匀性优于另外两种喷涂方式;采用同向的喷涂轨迹进行喷涂作业时,基体温度的波动幅度较另外两种喷涂方式小。通过设计梯度结构,并调控喷涂轨迹,可减小构件厚度方向的温度梯度,从而提升基体与涂层的结合强度。

Influence of Spraying Trajectory on Temperature Field of Plasma Sprayed Mo/8YSZ Functionally Gradient Thermal Barrier Coatings on Aluminum Alloy Surface

In order to break through the technical bottleneck of traditional Mo/8 YSZ double-layer thermal barrier coatings which is easy to be removed at high temperature,the influence of spraying trajectory on the temperature field of plasma sprayingfunctionally gradient thermal barrier coatings was studied.Based on the method of"life and death element",the finite element model of plasma spraying gradient thermal barrier coating was established by using ANSYS finite element simulation software.The latent heat of phase change and thermophysical parameters at different temperatures were considered in the model,and the distribution of temperature and temperature gradient of spray components under different spray trajectories were analyzed.The results showed that when the bonding layer and transition layer materials are sprayed,the temperature of the spraying components is the highest with same spraying trajectory.When the same material is used to spray in the same direction,and different materials are used to spray in the opposite direction,the temperature of the spraying components takes second place.And the spraying component temperature is the lowest when S-shaped spraying track is adopted.When the ceramic layer material is sprayed,the temperature of the spraying component is the highest when the S-shaped spraying track is adopted.The temperature of spraying components is followed when the same direction spraying trajectory is adopted.When the same material is sprayed in the same direction and different material is sprayed in the opposite direction,the temperature of the spraying component is the lowest.When the S-shaped spraying track is used for spraying,the uniformity of temperature distribution on the left and right ends of spraying components is better than that of the other two spraying methods.When the same direction spraying trajectory is used,the fluctuation range of substrate temperature is smaller than that of the other two spraying methods.By designing the functional gradient thermal barrier coating and adjusting the spraying trajectory reasonably,the temperature gradient in the direction of spraying component thickness can be further reduced and the bonding strength between the substrate and the coating can be improved.