The Numerical Analysis Of Energy Density During Inertia Friction Welding Process

Under the axial pressure and torque, the contacting surfaces and its adjoining region are brought to viscopiastic state and produce appropriate macroscopic deformation during inertia friction welding (IFW) process. Using the relative motion of rubbing surfaces and the plastic flow, then are upset rapidly. From the point of energy, basically, IFW is an energy consuming process. Therefore, it is very important to study the energy problem in the field of friction welding.In this paper, numbers of 2D axisymmetic thermo-mechanic coupled models for the simulation of similar pieces are developed, and by employing the elastic-plastic finite element method (FEM), the effect of energy density to the temperature fields, stress fields, welding times and axial shortening are calculated during IFW processes of the similar GH4169 superalloy. The results show that the relationship between energy density and welding time approximately is linear, and the welding time increased with the energy density, as well as the axial shortening. In addition, the more the energy density, the higher the temperature of the interface was, and the larger the flash was.In order to verify the dependability and validity of the models, the calculated data of welding time and axial shortening are compared to the measured ones, and they are shown in good agreement respectively.At the same time, the numerical models of different sized GH4169 superalloy and GH4169 superalloy-42CrMo steel are described. The energy problems of IFW processes are analyzed qualitatively. The results show that the energy density of the smaller weldment is larger, and its heat affected zone (HAZ) is wider, the temperature grads is the lower than the larger weldment under the same flux inputting condition. For the dissimilar pair, the increase of the temperature of 42CrMo steel is slower and lower, and the heated zone is wider, further more, its deformation is much more obvious and its flash is larger than GH4169 superalloy, because its plastic metal is extruded heavily, it is easy to produce welding disfigurements. And the models are helpful to optimize the dissymmetric and dissimilar friction welding technics for manufactures.