铝合金激光填丝焊对接接头疲劳性能分析

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Abstract：For the 3mm thick 6o82-T6 aluminum alloy sheet used in the body of the 350km/h Fuxing EMU， the laser filer wire welding processtest of butt joint was carried out with 5087 welding wire，and the fatigue performance test of the test plate wascarried out.By studying the macroand micro morphologyof the fracture surface of the test plate，the fracture features of the fracture surface were analyzed.The results show that when the number of cycles is 1×107 （specified life），the median fatigue limit σ0.1 of the butt joint of 6o82-T6 aluminum alloy with 3mm （ penetration depth is 87.5MPa ; The fatigue specimens are basically fractured in the welding heat affected zone of the base metal，andthefatigue lines ofthefractured specimensareclear，whichareclearlyvisible inthecrack initiation Zone and the crack propagation Zone，and at the same time show the iconic fracture features.When the number of cycles gradually increases，the range of the propagation zone is gradually expanded，and the fracture morphology of thefinal fracture zoneis dimple-shaped.The testresults provide technical helpforthe applicationof laser filler wire welding in long and large parts of aluminum alloy car body.

Keywords： laser filling welding; fatigue limit;heat affected zone; dimple; fracture

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铝及铝合金耐蚀性好、比强度较高、导热性以及低温力学性能良好，广泛应用于工业领域，尤其在高速轨道列车和地铁中使用了大量的铝合金焊接结构，整个车体均为铝合金型材拼焊而成。（剩余4483字）