Finite Element Analysis of Thermal Effect on Large Thick Titanium Alloy Electron Beam Welding with Different Focus

Abstract

A composite heat source model composed of Gaussian surface heat source and rotational paraboloidal body heat source have been established to simulate the temperature field of 20mm TA15 titanium alloy. The results show that the simulated peak temperature of molten pool during surface focus welding is 3200°C, while the simulated peak temperature of molten pool during lower focus is 2700°C, and the whole surface temperature of surface focus welding is higher than that of lower focus welding, while the whole inner temperature of surface focus welding is lower than that of lower focus. The simulated temperature gradient in the direction of depth during surface focus welding is large, but the simulated temperature gradient in the direction of depth during lower focus welding is small. The simulated result was verified by the thermocouple and contrast of weld cross section morphology. The simulated thermal cycle curves are well consistent to the results tested by thermocouple, and there is a good consistency between the simulated molten pool morphology and the real weld morphology, they verify the accuracy of finite element model.