Ti17钛合金线性摩擦焊温度场的有限元分析

Finite Element Analysis of Temperature Field during Linear Friction Welding of Ti17 Titanium Alloy

建立了Ti17钛合金线性摩擦焊（LFW）有限元模型,利用有限元软件ABAQUS模拟研究了LFW过程中的温度场变化规律,并进行了Ti17钛合金的LFW试验,采用扫描电镜研究了接头的显微组织。结果表明：LFW接头界面温度超过β转变温度,随着与摩擦界面距离的增大,温度逐渐降低,且温度随距摩擦界面距离呈指数规律变化;焊后界面温度的冷却速度高达200℃/s。LFW接头焊缝组织为细小的等轴晶粒,热机影响区的组织沿着受力方向被拉长,热影响区中细小二次α相发生溶解现象。

The LFW finite element model of Ti17 titanium alloy was established, and the temperature change rule during LFW was studied by using the finite element software ABAQUS. The LFW test of Ti17 titanium alloy was carried out and the microstructure of the joint was observed by scanning electronic microscopy（SEM）. The results show that that the interfacial temperature of LFW joint is above the β transition temperature. With the increase of the distance from the friction interface,the temperature gradually decreases, and the temperature changes in exponential law with the distance form the friction interface. The cooling rate of the interfacial temperature reaches 200 ℃/s after welding. The microstructure of weld zone of LFW joint is fine equiaxed grain, the microstructure of the thermo-mechanically affected zone is elongated along the stress direction, and some fine secondary α phases are dissolved in the heat affected zone.