Influence of Gas Tungsten Arc Welding Parameters in Aluminium 5083 Alloy
The present work deals with the identification of the best combination of welding parameters, in TIG welding of Aluminium alloy 5083. In this study two level full factorial experimental design is considered which consists of two factors and two levels. Inorder to avoid experimental errors two replications are performed for each experimental combination. The working ranges of welding parameters for conducting experiments are initially obtained by trial and from literature survey. After the experiment, various tests like Tensile test; Microhardness, Macrostructure and Microstructure study are conducted to the welded specimens. The analysis of the test results is conducted and the combination of welding parameter ranges that gives best result is found. This combination can be considered as good working ranges for TIG welding of Aluminium alloy 5083.
The effects of residual stresses on the fatigue life of 5083-O aluminum alloy spot welded joints
Abstract In this study, resistance spot welding (RSW) process of 5083-O Aluminum alloy has been simulated numerically using an axisymmetric model of electrodes and sheets, and then the effects of residual stresses have been investigated on the fatigue life of the joints. All process parameters except electrode clamping force have been considered to be constant during RSW. Three different electrode force level have been considered and then dimensions of nuggets, HAZ and gaps have been obtained numerically. Three kinds of spot welded models with three different gap values between sheet joints have been simulated using Ansys code. Non-linear analysis was performed to obtain the local stress and strain ranges and then, Morrow equation with particular consideration of residual stress and gap distance effects has been applied to estimate fatigue lives. The results show that, with increasing the electrode force, the gap values between sheet joints increase. The results also reveal that the center region and the roots of nuggets have surrounded by the relatively large amounts of tensile residual stresses and also increasing the electrode force, reduce the amounts of residual stresses. The comparison between numerical results of fatigue lives and experimental data provided good agreement between numerical predictions and experiments.
INFLUENCE OF DIE DESIGN AND PROCESS PARAMETERS ON WORKING LOAD AND DAMAGE DURING EQUAL CHANNEL ANGULAR PRESSING
Equal Channel Angular Pressing (ECAP) is one of the most effective Severe Plastic Deformation (SPD) techniques for grain refinement in metallic materials. One of the technological problems of ECAP is processing the material by large strain without cracking of the workpiece. The aim of paper is to investigate the damaging and load evolution during ECAP of aluminum alloys. A Finite Element Analysis (FEA) was performed for different die designs and process parameters to depict the influence of die geometry and friction condition on deformation behavior and material damaging. Experimental tests were performed for testing the numerical prediction.The results provide a useful tool for optimizing ECAP process avoiding tool and billet damaging.