TC4钛合金激光深熔焊小孔形貌特征的有限元精细分析

Numerical Simulation for Keyhole Profile and Their Effect of TC4 Titanium Alloy during Laser Welding

摘要:

针对TC4钛合金激光深熔焊接的特点，建立了适合小孔尺寸精度的微米级精细计算模型。结合TC4钛合金材料属性，利用能量分布与小孔形貌特点相类似的高斯旋转曲面体热源进行加载，得到了随激光焊接工艺参数改变而变化的小孔形貌及瞬态温度分布特征。通过分析瞬态过程小孔前后沿、小孔径向以及小孔深度方向的特征尺寸及温度分布，得出了对TC4钛合金激光焊接小孔形貌影响最大的工艺参数。通过分析各工艺参数的影响规律，提出了TC4钛合金激光焊接得到最佳小孔形貌或温度分布的工艺参数取值范围。

Abstract:

According to the characteristics of the existence of keyhole phenomena on TC4 titanium alloy during laser welding, a precise calculation model fitting to the keyhole size in micron dimension has been developed. Using the Gaussian rotating curved body heat source fitting for the keyhole profile and combining the material property of TC4 titanium alloy, the distribution characteristics of keyhole profile and transient welding temperature varying with the laser parameters have obtained. The greatest influences of laser welding parameters on keyhole profile of TC4 titanium alloy have been found out by analyzing the specificity size and temperature distribution in front and back edge of the keyhole and in radial and depth direction of the keyhole. The optimal range of laser welding parameters to obtain the best keyhole profile and temperature distribution of TC4 titanium alloy during laser welding has been found out by analyzing the influence of every welding parameter.