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Effects of Process Parameters on the Bead Formation During Laser Seal Welding of Ultra Thin Titanium Shell

Due to the effects of manufacture techniques and heat distortion in welding, laser seal welding for ultra thin titanium shell is quite difficult. An Nd: YAG pulse laser system is used to seal 0.3mm thick medical titanium implant in the paper. The effects of process parameters including pulse wave shape, laser power, welding speed, defocusing amount, and shielding gas are investigated. Finally parts of the welded specimens are analyzed by helium leakage detector. The results show that flat wave shape is optimum choice for seal welding, reasonable collocation of laser power and welding speed guarantees the welding quality, and the effect of bead color is good when the flux of the shielding gas is 15 L/minute. After a serial of technique experiments, the welding specification for sealing ultra thin titanium shell is confirmed. It provides reference for engineering application and optimization the seal welding further.