Equal channel angular rolling (ECAR) process is one of the severe plastic deformation (SPD) methods that have been used to make ultra-fine grain (UFG) materials with improving the mechanical properties of samples. After performing the process at several paths, a large strain is applied to the material that can cause decreasing the grain size and improving the mechanical and physical properties ...

A finite element scheme for simulation of welding residual stresses is presented in this paper. Detailed thermal and residual stress analyses for butt-welded and socket-welded pipes are performed using ANSYS and ABAQUS. The calculated distribution of axial stress and hoop stress at welded joint are validated against experimental results. Furthermore, residual stress relaxation under high amplit...

This study represents simulation of single spot and multi spot welded specimen by using Monte carol method i.e. Latin hypercube sampling. A three dimensional nonlinear finite element analysis of multi-spot welded lap shear specimen is performed and uncertainty in shear strength of spot weld is analyzed. Thickness and nugget radius are randomly varied within effective range and their effect on t...

Friction welding of cast Fe-40Al alloy was carried out at 1000 rmp for various friction times, friction pressures, and forging pressures. The microstructures of the interface of welded samples were analyzed by optical and scanning electron microscopy (SEM). Micrographs demonstrated that excellent welding formed continuously along the interface, except for samples welded for 3 s. Chemical compos...

The fatigue fracture of structural details subjected to cyclic loads mostly occurs at a critical cross section with stress concentration. The welded joint is particularly dangerous location because of sinergetic harmful effects of stress concentration, tensile residual stresses, deffects, microstructural heterogeneity. Because of these reasons many methods for improving the fatigue resistance o...

Aluminium and its alloys are commonly used in shipbuilding structures applications as include main strength members such as hulls, deckhouses and other applications as stack enclosures, hatch covers, windows, air ports, accommodation ladders, gangways, bulkheads, deck plates, ventilation equipment, lifesaving equipment, furniture, hardware, fuel tanks and bright trim. Separately interesting is ...

This study investigated the joint properties of Fe-Pt alloy laser-welded to Co-Cr alloy. Cast plates (0.5 x 3.0 x 10 mm) were prepared with Fe-Pt and Co-Cr alloys. Fe-Pt plates were butted against Co-Cr plates and laser-welded using Nd:YAG laser. Control and homogeneously welded specimens were also prepared. Laser welding was performed with and without argon shielding. Tensile testing was condu...

As a new treatment process after welding, the process parameters of laser shock peening (LSP) in dynamic strain aging (DSA) temperature regimes can be precisely controlled, and the process is a non-contact one. The effects of LSP at elevated temperatures on the distribution of the surface residual stress of AA6061-T6 welded joints were investigated by using X-ray diffraction technology with the...

In this study, 7075 aluminum alloy with a thickness of 10 mm was successfully welded with no obvious defects by pulsed variable polarity plasma arc (PVPPA) welding. The mechanical properties of PVPPA welded joints have been researched by post weld heat treatment (PWHT). The results indicate that the heat treatment strongly affects the mechanical properties of the welded joints. The tensile stre...

Ultrasonic peening treatment (UPT) as a method of severe plastic deformation was used to treat cruciform welded joints of Q345 steel. The application of UPT achieves material surface nanocrystallization of the peening zone, reduces stress concentration, and produces residual compressive stresses at the welded toe. Micro-structure, hardness, stress relief, S-N curve, and the fatigue fracture mec...