Numerical Simulation Of Temperature Field And Stress Field Of Electron Beam Brazing Two Kinds Of Radiator

6139T and 6204T radiator with tube to tube-sheet joints are important components applied in aerocraft engine. Using the conventional vacuum furnace brazing to braze these components, it can't meet the requirement of design and performance due to the integral heating of the base and brazing filler and the long time of heating and cooling. As a new brazing technique combined electron beam machining with vacuum brazing, electron beam brazing (EBB) has some advantages of high efficiency, energy conversation and small deformation, etc. It is suitable to braze these components.According to the property of EBB, scanning electron beam was considered as plane heat source instead of spot heat source in this paper. Aiming at the problems to measure the real-time temperature and residual stress of radiator difficultly at high temperature, the two-dimensional finite element models were established. Based on the thermal elastic-plasticity, the temperature fields and stress fields of EBB 6139T and 6204T radiator by two kinds of process were simulated by the software of ANSYS. It is of great value and significance to guide actual production. The main results were obtained as follows:(1) The calculation results of temperature field indicate that, 6139T radiator was brazed using the stage-by-stage heating process, while 6204T radiator with a larger size was brazed using the temperature difference heating process. The uniform temperature distributions in faying faces were all obtained. And the temperatures were in the range of brazing temperature. It is proved that the finite element models established are reasonable.(2) The calculation results of stress field of EBB 6139T radiator indicate that, for radial residual stress, the obvious stress concentration region was found in faying face using direct-heating process; while there was no stress concentration in faying face and the change curve of residual stress using stage-by-stage heating process was flatter than that of direct-heating process. For circumferential residual stress, compared stage-by-stage heating process with direct-heating process, the peak value of tensile stress reduces by 11.2%.(3) The calculation results of stress field of EBB 6204T radiator indicate that, for radial residual stress, the change curve of residual stress using temperature difference heating process was flatter than that of stage-by-stage heating process. For circumferential residual stress, compared temperature difference heating process with stage-by-stage heating process, the peak value of tensile stress reduces by 13.4%.(4) Whether 6139T radiator or not 6204T radiator, compared circumferential residual stress with radial residual stress by two kinds of EBB process, it shows the peak value of circumferential tensile stress is higher than that of radial tensile stress. So the dangerous position is along circle direction, namely, the heating direction of scanning electron beam.