| Linear Friction Welding (LFW), as a precision welding technique, has been successfully used to manufacture and repair blisks (a single component composed of a disk and blades) in aircraft engines of high thrust-weight ratio abroad. It is important to investigate the temperature variation and distribution during LFW for clarifying the physical mechanisms of LFW and further process.In this paper, a simplified model for LFW vibration system was established and the frictional heat flux at different regions of the interface was analyzed. In addition, the correlation between the frictional heat flux and friction coefficient μ was obtained by collecting the voltage and current values of the drive motor.Base on the above-mentioned results, a 3-dimensional finite element analysis (FEA) model was developed using a commercial software ANSYS for calculating the temperature field during LFW 45 steel. The changes of temperatures at the weld center and heat-affected zone (HAZ) were examined.On the other hand, the experiments with the quenched 45 steel were done under different LFW parameters. It was found that the axial shortening of the joint increased exponentially with the increase of friction time. The microstructure observation showed various structures were evolved at different regions of joint, which corresponds to different temper temperatures during LFW. The microhardness of the joint also presented gradual variations from the weld center to the parent 45 steel. Based on these results, the relation between the tempering temperature and microhardness of the joint was obtained, and thus the temperature field of the joint was established. Compared to the temperature field obtained by FEA, the inferred temperature filed was a little different. But through amending the simulation model, the temperature filed could be estimated correctly by FEA. These results are of significant importance to carry out the further LFW experiment in terms of the theory development and industrial applications. |
PDF Full Text Request