This thesis presents a collection of theoretical and experimental investigations into various geometrical aspects of hybrid laser-MIG welding. The work is divided up into four parts; 1. A review of the hybrid laser-MIG welding technique with brief summaries of the three papers which make up the remainder of the thesis. 2. A paper entitled “Fundamental analysis of hybrid laser-MIG welding”. This...

Titanium alloy TC1 and Aluminum alloy LF6 were butt jointed and lap jointed by friction stir welding (FSW), and the influence of process parameters on formation of weld surface, cross-section morphology and strength were studied. The results show that, Titanium and Aluminum dissimilar alloy is difficult to be butt joined by FSW, and some defects such as cracks and grooves are easy to occur. Whe...

Plates of 3–5 mm in thickness were extracted from an AZ91D ingot and then butt joints of the plates were produced using tungsten inert gas (TIG) welding method. The TIG arc was also used to deposit welding beads on some of the thin plates. No cracking was found in the butt joints. However, hot cracking was always observed to propagate from the heat affected zone (HAZ) under the welding bead int...

For hot extrusions of magnesium alloy sheets, Dissimilar AZ80 and AZ31 were used, in which AZ80 was placed on advancing side and AZ31 on retreating side, using friction stir butt welding with different process parameters. Some defect-free welded joints with good weld surfaces could be obtained with some suitable welding conditions. The maximum tensile strength of welded joint which is 225.5 MPa...

It is well known that the residual stress of the friction-stir-welded joint affects the fatigue strength and life, and the corrosion performance. In this paper, a three-dimensional finite element model is established to study the thermal history and stress evolution in the butt welding of aluminium alloy 6061-T6, which will comprehensively provide insight into the friction-stir-welding process....

This paper considers a 3-D thermos-mechanical analysis to investigate the effect of welding direction, tack weld, root gap and process on deformation in hub flange pipe joint. Multi-pass for single ‘V’ butt-weld joint geometry is simulated weld path used with realistic bead. 3 different direction (2-path, 4-path diagonally, from bottom) are analyzed how presence or absence affects was analyzed....

In this research article a comprehensive investigation has been carried out to determine the effect of thermal cycle on temperature dependent process parameters developed during gas tungsten arc (GTA) welding of high carbon (AISI 1090) steel butt joints. An experiment based thermal analysis has been performed to obtain the thermal history. We have focused on different thermophysical properties ...

This paper deals with an experimental investigation on the friction stir welding of pure copper. 4 mm thick copper plates have been welded in the butt joint configuration using a conical unthreaded tool, with and without preheating. An electrically heated backing plate has been employed to increase the initial temperature of the plates and to investigate the influence of pre-heating on the weld...