Keyhole formation and collapse in plasma arc welding

A mathematical model is developed to describe the heat transfer and fluid h ow in stationary keyhole plasma are welding. Using the volume of fluid meth od, the processes of heating, melting, collapsing and subsequent solidifyin g in the molten pool are dynamically studied. The predicted results have be en compared with the experimental weld and keyhole shape. Using the LaserSt robe video system, the captured images of the upper surface of the weld poo l are used to verify the predicted transient development of the weld pool. It is indicated that theoretical predictions and the experimental results a re in close agreement.