激光沉积修复TA15钛合金热应力的数值模拟

Numerical Simulation of Thermal Stress of Laser Deposition Repair of TA15 Titanium Alloy

根据激光沉积修复的热传导特点,利用有限元法中的生死单元技术,建立了激光沉积修复TA15钛合金的过程模型,采用参数化设计语言编程实现对多道多层激光沉积修复过程三维热应力场的数值模拟。研究了不同功率、不同扫描速度下以及对修复基体预热后热应力的动态分布规律,并对热应力变化的原因进行了分析。结果表明,随着激光功率的减小、扫描速度的增大热应力呈减小趋势,对修复基体预先加热,可以有效调控热应力的产生和演化,为降低激光沉积修复过程中的热应力,提高修复质量提供理论依据。

Laser deposition repair of TA15 titanium alloy process model is established by using＂element birth and death＂technology of finite element method,according to the heat transfer characteristics of laser deposition repair,the numerical simulation of three-dimensional thermal stress field during multi-track and multi-layer laser deposition repair process is developed with ANSYS parametric design language（APDL）.The dynamic distribution of thermal stress under different laser power,different scanning speed and the preheated repairing is studied,the reason of variations of thermal stress is analyzed.The results indicate that thermal stress decreases with the decreasing of laser power and the increasing of scanning velocity,the generation and evolution of thermal stress can be controlled by preheating repair substrate.Theoretical basis is provided in order to reduce the thermal stress of laser deposition repair and improve the repair quality.