扭转载荷作用下熔接涂层与基体结合界面处应力特性仿真研究

Simulation Study on Stress Characteristics of Fusion Bonded Coating and Substrate Bonded Interface under Torsional Loading

目的通过有限元仿真获得熔接涂层与基体结合界面处的应力分布特性,得到熔接涂层与基体的力学性能匹配性。方法应用ABAQUS有限元软件,将模型沿轴向和径向剖切,讨论不同扭矩载荷下镍基合金涂层和基体轴结合界面的应力分布规律,分析涂层厚度对结合界面处应力的影响。结果从模型剖切后采样结点的应力变化曲线看,基体和涂层的内部应力变化均匀,在基体和涂层结合处应力存在突变,涂层上的应力大于基体上的应力。涂层厚度从0.5 mm增大到1.0 mm时最大应力减小量约为18 MPa,从1.0 mm增大到2.5 mm时最大应力的减小量约为1 MPa,涂层厚度大于1.0 mm后最大应力减小量变化不明显。结合面两侧涂层和基体应力差值的最大值Δσ_(max)随着涂层厚度的增大有所减小,在涂层厚度小于1.0 mm时,变化较为明显。结合面底面处的应力突变随涂层厚度的增加而略有减小。结论在涂层和基体结合界面处存在应力突变,最大应力出现在涂层外表面的中心位置,增大涂层厚度可以减小应力突变,在涂层厚度较小时效果明显。

The work aims to obtain stress characteristics of the interface between fusion bonded coating and substrate by virtue of finite element simulation, then further acquire mechanical property compatibility of the fusion bonded coating to the substrate. ABAQUS finite element software was used to slice model along the axial and radial direction, stress distribution rules of the interface between nickel base alloy and the substrate shaft under different torque loads were discussed, and the effect of coating thickness on the stress at the interface was analyzed. According to stress changing curve of the sampled nodes, the internal stress change of the substrate and coating was uniform. The stress on the interface between the substrate and coating was subject to sudden change. The stress on the coating was higher than that on the substrate. The maximum stress reduced by nearly 18 MPa as the coating thickness increased from d1=0.5 mm to d2=1.0 mm; the maximum stress reduced by nearly 1 MPa as the coating thickness increased from d1=1.0 mm to d2=2.5 mm; the maximum stress reduced slightly after the coating thickness exceeded 1.0 mm. Maximum stress difference Δσsmax between coatings on both sides of the interface and the substrate interface reduced with the increase of coating thickness. More obvious changes were present when the coating thickness was less than 1.0 mm. Stress at the bottom of the interface reduced slightly with the increase of coating thickness. Sudden stress change is present at the interface between the coating and substrate. The maximum stress is present in the center of outer surface of the coating. Increasing the coating thickness can reduce the sudden stress change and obvious effects are present when the coating thickness is low.