Effect of Viscosity on the GTA Welds Bead Penetration in Relation with Surface Tension Elements

The aim of this paper is to study the effect of the viscous dissipation on the surface tension and its role on the shape of weld pool. Experiments were conducted on four different casts of ferritic stainless steel with different content in the sulfur and titanium. The results show in particular that the presence of titanium solid compounds affects the role of sulfur as surfactant element. Titanium in the presence of carbon and oxygen, titanium forms solid compounds which affect the Marangoni convection due to the sulfur element in the weld pool. The viscous dissipation due to these compounds alters the flow rate of the molten metal. We expect that the viscosity of metal liquid was altered by these solid compounds. The viscous dissipation due to these compounds contributes to heat the molten metal leading to larger weld bead.

Application of the Hybrid Metal Extrusion & Bonding (HYB) Method for Joining of AA6082-T6 Base Material

In the present investigation the new HYB spindle extruder has been used for butt joining of 4 mm thick aluminium plates of the AA6082-T6 type at RT in one pass, employing a 1.6 mm diameter filler wire of matching composition. The test joint produced was subsequently sectioned and subjected to thorough examination in the laboratory, which included visual inspection of the surface quality and bead penetration depth, optical microscopy for visualisation and documentation of the material flow pattern and the microstructure within the joining zone and Vickers hardness testing. It is concluded that strict control of the bead penetration depth is necessary in order to obtain full bond strength. This is because the bead penetration determines the contact pressure between the filler metal and the base metal in the groove during filling.

Through-Thickness Stresses in Automotive Sheet Metal after Plane Strain Channel Draw

A series of samples from four automotive materials - AKDQ, HSLA50, DP600, and AA6022-T43 - were deformed in a channel draw processes with different levels of draw bead penetration. As a result, varying magnitudes of deformations in plane strain mode and residual stresses were obtained. Through-thickness stress profiles were obtained non-destructively using a novel, high resolution X-ray diffraction technique.