Search results for " Welding"

Friction stir welding FEM model improvement through inverse thermal characterization

2005

Solid state joining of thin hybrid sandwiches made of steel and polymer: A feasibility study

2020

The growing demand for more environmentally friendly vehicles has led to an increased use of light materials in the transportation industry with the aim to reduce structural weight, fuel consumption, and gas emissions, thereby boosting cost-effectiveness and recyclable properties. Complex multi-material steel-based components would allow to improve mechanical properties and minimize weight even further. In particular, new sandwich materials made by steel outer skins and a polymeric internal layer seems very promising for obtaining mechanical performance and lightness at the same time. Unfortunately, traditional welding techniques, like arc welding, laser welding, and resistance spot welding…

Recent advances in sheet metal single point incremental forming and friction stir welding

2011

Prediction of phase evolutions during friction stir welding of Ti-grade 5 T-joints using finite element modeling

2022

Friction Stir Welding (FSW) is a solid-state welding technology pioneered by The Welding Institute (TWI) in 1991. Originally used to weld aluminum alloys, it is now effectively utilized to weld high-resistance materials as well. The ultimate mechanical characteristics of the joints are inextricably linked to the microstructural evolutions that occur during the process in terms of phase change. It is then crucial, in order to carry out an effective process engineering, to predict the final material microstructure determined by the thermal history that occurred during the process itself. In the paper, a 3D Finite Element Method (FEM) model for the FSW of T-joints is proposed, based on a therm…

Experimental Comparison of the MIG and Friction Stir Welding Processes for AA 6005 Aluminium Alloy

2015

In this study, the mechanical properties of welded joints of AA 6005 aluminum alloy obtained with friction stir welding (FSW) and conventional metal inert gas welding (MIG) are studied. FSW welds were carried out on a semi-automatic milling machine. The performance of FSW and MIG welded joints were identified using tensile and bending impact tests, as far as the environmental aspects are also included in the discussion. The joints obtained with FSW and MIG processes were also investigated in their microstructure. The results indicate that, the microstructure of the friction stir weld is different from that of MIG welded joint. The weld nugget consists of small grains in FSW than those found…

3 Probing and Modelling of Galvanic Coupling Phenomena in Localized Corrosion

2011

The basic driving force of localized corrosion or corrosion protection in numerous cases is the galvanic coupling of which the dimensional aspect is fixed by a combination of scales regarding interfacial processes or properties. At the electrolyte–metal interface, it is necessary to consider the microstructure (including all real-time modification induced for example by applied stresses), the possible chemical changes at the surface of the material, and the electrolyte conductivity contribution, among others factors.

Effect of Process Parameters on the Joint Integrity in Friction Stir Welding of Ti-6Al-4V Lap Joints

2013

Friction Stir Welding (FSW) is a solid state welding process patented in 1991 by TWI; initially adopted to weld aluminum alloys, is now being successfully used also for magnesium alloys, copper and steels. The wide diffusion the process is having is due to the possibility to weld materials traditionally considered difficult to be welded or “unweldable” by traditional fusion welding processes due to peculiar thermal and chemical material properties. Additionally, the process allows welding a wide range of sheet thickness (up to 50mm) avoiding typical fusion welding processes defects, like cavities and porosities, with no shielding gas, filling material or joint preparation. Recently, researc…

Characterization of Fusion Lines Obtained with Laser Welding on Ductile Iron Plates

2016

This paper studies the ductile iron (DI) weldability using laser welding. For performing an Yb:YAG continuous laser was used, with a maximum power of 6 kW. The parametrical window power (P) - welding speed (S) was explored by carrying out the fusion lines on ductile iron plates without preheating, to determinate areas of weldability (complete penetration, correct geometry) to allow further characterization. The criteria for selection of focus areas were the geometry of the fusion lines and the absence of the welding defects. The unsatisfactory domains were characterized by: collapse of the melted metal, incomplete penetration, low fusion lines quality (geometry, compactness). In present stu…

Microstructure and property of titanium heterogeneous laser welding

2015

International audience; Dissimilar welding has been investigated for three different couples of titanium alloys: α/α+β, α/β and α+ββp. Plates of 100 x 60 x 1.6 or 1.8 mm were welded with a Yb: YAG laser. Tensile tests show that the properties of the dissimilar welded specimens were generally controlled by Those of the weakest material except for the α+β/β where the ultimate tensile strength was approximately equal to the average value of both materials. In every case, the welding sample elongation was found to be smaller than that of the base metals. The rupture took place away from the bead and was found to be always located in the alloy having the lowest mechanical properties. Nevertheles…

Infrared thermography for monitoring heat generation in a linear friction welding process of Ti6Al4V alloy

2017

Abstract The increasing use of titanium alloys in a wider range of applications requires the development of new techniques and processes capable to decrease production costs and manufacturing times. In this regard welding and other joining techniques play an important role. Today, solid state friction joining processes, such as friction stir welding, friction spot welding, inertia friction welding, continuous-drive friction welding and linear friction welding (LFW), represent promising methods for part manufacturing. They allow for joining at temperature essentially below the melting point of the base materials being joined, without the addition of filler metal. However, the knowledge of te…