Research On Pulsed Laser Welding Procedure Of Titanium Alloy

With the advantages of low density, high strength-to-weight ratio and superior corrosion resistance, titanium alloys have been widely applied in the fields of aircraft and automobile industries。In numerous welding method of titanium alloy, the pulse laser welding with high energy density, weld and heat affected zone small, small distortion and more and more widely used. In the aerospace titanium wall structure laser welding porosity is a common flaw, its serious impact on the fatigue properties of titanium alloy structure.In this paper, we research the Titanium alloy weld formation and the porosity affects of pulse frequency, laser power, welding speed, pulse width and other parameters based on the 3 mm TC4 titanium alloy. Though the weld formation and weld porosity, pulse frequency of weld has large influence on weld porosity, and too large pulse frequency or too small is not conducive to weld formation and the control of weld porosity; Laser power is the basic cause of weld porosity,porosity is not a linear relationship wih the laser power in the weld; Welding speed is more complicated on porosity in the weld and it is related to the stability of the porosity in the process of laser welding; Pulse width of weld porosity influence is relatively simple—— the weld porosity decrease with the increase of pulse width.In addition,the comparison of two laser output kinds of welding process, we found that continuous laser welding and pulse laser welding titanium alloy can get ideal weld and high tensile strength.But the intermittent energy of pulse laser welding and the intense agitation of molten pool make weld various elements distribution more uniform.So pulse laser welding can get a more excellent welding quality, and it has greater microhardness and stronger tensile strengt.