GH4169惯性摩擦焊界面摩擦及瞬态热过程数值模拟研究

Numerical Simulation of Interfacial Friction and Transient Thermal Processes in Inertia Friction Welding of GH4169 Superalloy

针对GH4169高温合金惯性摩擦焊过程,基于有限元方法研究了界面摩擦机制的转变、摩擦产热和温度场等热过程参量的分布特征及瞬态演化规律。利用试验数据对有限元模型的准确性进行了对比验证。结果表明,焊接初始整个界面均为库仑摩擦区,从0.54 s开始库仑摩擦区逐渐缩小并在9.60 s完全消失,剪切摩擦区从0.31R0(R0为工件半径)处开始形成并逐渐扩展至整个界面。根据模拟结果,提出了描述库仑摩擦区演化过程的解析公式。分析了摩擦机制转变引起的界面热流密度、摩擦应力和温度的耦合关系及变化规律。研究表明,界面上库仑摩擦机制向剪切摩擦机制的转变有利于焊接界面附近温度场的均匀化。

For the inertial friction welding(IFW)of GH4169 superalloy,a finite element(FE)simulation model was established to investigate the transition of interfacial friction regime and transient evolution law of thermal processes variables such as heat generation and temperature.The accuracy of the FE model is verified by the experimental data.The results show that the Coulomb friction zone occupies the whole interface at the beginning of the welding process,and gradually shrinks from 0.54 s and disappears completely at 9.60 s,while the shear friction zone builds up at 0.31R0(R0 is the radius of the workpiece)and expands to the entire interface.Based on the simulation results,an analytical equation describing the evolution of the Coulomb friction zone is proposed.The coupling relationship and variations of heat flux,frictional stress and temperature at the interface caused by the transition of friction regime are analyzed.The results show that the transition of interfacial friction regime from the Coulomb friction regime to the shear friction regime is beneficial for temperature homogenization at the interface.