Papers by Keyword: Molten Zone

Abstract: In this work, the heat transfer by conduction and convection mode and effect of fluid flow on the morphology of the weld pool and the welding properties is investigated during Tungsten Inert Gas (TIG) process. In the first part, a computation code under Fortran was elaborated to solve the equations resulting from the finite difference discretization of the heat equation, taking into account the liquid-solid phase change with the associated boundary conditions. In order to calculate the velocity field during welding, the Navier-Stokes equations in the melt zone were simplified and solved considering their stream-vorticity formulation. A mathematical model was developed to study the effect of the melted liquid movement on the weld pool. The evolution of the fraction volume of the liquid and the thermal fields promoted the determination of the molten zone (MZ) and the Heat Affected Zone (HAT) dimensions, which seems to be in good agreement with literature.

Abstract: In this study Al/Cu laminated composite specimens were obtained via explosion welding at various modes. Microstructure, chemical composition and microhardness of Al/Cu bond area were investigated by means of optical and SEM microscopy. Four typical microstructures of Al/Cu bond area were identified at different explosion welding parameters. The types included various amounts of molten zones in the structure. The evolution of the molten zone hardness value identified explosion welding regimes which contributed to maximum amount of intermetallic compound formation during explosion welding.

Abstract: The wide use of clad joints in practical application has been inhibited due to the difficulty in welding certain combinations such as tungsten/-copper, molybdenum/-copper and magnesium with aluminum, titanium and stainless steel. These material combinations are generally classified as difficult to weld by conventional material joining techniques due to the vast difference in material properties and the degradation of mechanical properties of the joints. Explosive welding is here a viable alternative technique. Explosive welding is a solid-phase welding process that uses the energy of a detonating explosive to create a strong metallurgical bond. This technique has achieved impressive success in the joining of metallurgically incompatible combinations that are otherwise impossible to join by conventional welding techniques. Though the technique is suitable for joining only thin plates, it is efficient in joining some difficult to join combinations like magnesium with aluminum, titanium and stainless steel. In this paper, the result of welding titanium and magnesium was reported.