Dual Focus Nd:YAG LaserWelding of Titanium Alloys: Effect on Porosity Formation
J.E. Blackburn, C.M. Allen, A.H. Khan, P.A. Hilton and L. Li
The dual focus technique has been considered as a method for reducing porosity formation when Nd:YAG laser welding of titanium alloys. Response surface methodology has been used to examine the effects four process variables – foci orientation, foci separation, welding speed and power ratio – have on the formation of porosity. The statistical results and high speed imaging have shown that both transverse and in-line foci orientations, with controlled foci separations and welding speeds, can be used to establish a stable elongated keyhole, promoting low porosity welds.
Keywords: Nd:YAG laser, dual focus, welding, titanium alloy, porosity, high speed imaging, statistical analysis