Study of effect of process parameters on titanium sheet metal bending using Nd: YAG laser

Laser Bending is a new non-contact technique of forming sheet-metal components. This method has been extended to bend Titanium components in industry. In Titanium laser bending process serious issues such as oxide film formation and subsequent deleterious changes in material properties are encountered. This paper investigates methods to minimize oxidation with minimal change in bending results for Grade-2 Titanium. Inert gas shielding is used as a means of reducing oxidation. Different gas flow conditions, nozzle positions and inert gas combinations are used to enhance the bend quality and bend angle. These process changes lead to final bending angle increase and decrease in width of Heat Affected Zone (HAZ), section thickness of sheet at HAZ and surface hardness. Also as Grade-2 Titanium is highly reflective, different coatings have been used to improve the absorption of laser beam which resulted in further increase in bending angle.

► Laser Bending theory was applied to thermomechanical heating with inert gas shielding.
► Bending angle is regulated by altering the shielding gas parameters.
► Cooling effect adversely affects hardness of the plate yet can be easily regulated.
► We studied different gas flow conditions to enhance the bend quality and reduce HAZ.
► Use of coatings improved absorption of laser beam and increased the bending angle.