Numerical modelling of shielding gas flow and heat transfer in laser welding process

• In the present study a three-dimensional model has been developed to study shieldinggas in a laser welding process using computational fluid dynamics. Laser heatingof titanium alloy Ti6Al4V was done by imposing a volumetric laser heat source. Themodel was implemented in the open source software OpenFOAM and applied to theinvestigation of the shielding gas behaviour over the base metal.Three different cases regarding the outlet shape of the shielding pipe were studied. Insome laser welding processes a shielding plate is used to help protecting the weldedarea. The plate injects the additional shielding gas screen during the welding process.This plate is also considered in the modelling as the fourth case.The influence of the shape of the pipe outlet is discussed.The simulation results confirmedthat the shielding plate can protect the welded area by covering the welding pathwith shielding gas. However, the simulation showed that the shielding gas leaving theplate flows towards the keyhole. It can thus bring some fumes over the keyhole whichis not desired since it can make it difficult to track the welding with optical method.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Bearbetnings-, yt- och fogningsteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Manufacturing, Surface and Joining Technology (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Strömningsmekanik och akustik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Fluid Mechanics and Acoustics (hsv//eng)

Keyword

laser welding

shielding gas

volumetric heat source

coupling boundary

Publication and Content Type

kon (subject category)

ref (subject category)