Ti-6Al-4V基体上等离子喷涂羟基磷灰石涂层的热-力耦合（英文）

Thermal-Mechanical Coupling in Plasma-Sprayed Hydroxyapatite Coating on Ti-6Al-4V Substrate

在考虑了温度与变形之间的相互作用后,对经典的Fourier瞬态热传导方程进行了修正,并采用适合于高温及高应变率条件下的热弹塑性方程作为本构模型,从而建立了在Ti-6Al-4V基体上等离子喷涂羟基磷灰石涂层这一独特条件下的热-力耦合模型。据此,采用有限元方法对温度场和残余应力场进行了耦合求解。模拟了基体预热温度对涂层各个残余应力分量的影响。此外,为了能得到定量的比较,还采用了"材料去除"的实验技术测试了涂层在界面处的残余应力。结果表明:计算结果与实验结果吻合;在界面的边缘处有明显的应力集中;适当提高基体的预热温度对于减少残余应力是有帮助的。

After considering the interactions of the temperature and deformation during plasma spraying,the classical Fourier transient heat conduction equation was modified,and the thermal elastic-plastic nonlinear constitutive equation,suitable for high temperature and high strain rate conditions,was employed.Thus,a thermal-mechanical coupling model was developed according to the special case of plasma-sprayed hydroxyapatite coating on Ti-6Al-4V substrate.Based on the above coupling model,the temperature field and residual stress field were coupling solved by the finite element method.The effect of substrate preheating temperature on residual stress components was also simulated.Moreover,the material removal method was used to evaluate the residual stress of coating near the interface to get a quantitative comparison.The results show that,the calculated result is consistent with the experimental result;obvious stress concentration appears near the interface edge;it is helpful to reduce the residual stress by increasing properly the substrate preheating temperature.