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...

Irradiation-induced hardening is an important phenomenon concerning the nuclear reactor safety, because it induces the embrittlement of reactor pressure vessel steels. This phenomenon, however, can also be applied for the modification of hardness of alloys. In the case of FeCu alloys, we have reported that GeV heavy-ion irradiation remarkably increases the hardness [1]. Volkov et al. have expla...

Because numerical simulations with classical Johnson-Cook formulation of explosively formed projectiles induce non representative projectiles, a modified Johnson-Cook model taking into account the thermally activated and viscous regimes as well as the notion of saturation stress in the 10 s regime has been developed. Using both models, numerical experimental comparisons of Taylor and explosivel...

The Nd:YAG laser welding was used to join the binary NiTi alloy wires with different compositions(Ti–50.0 at.%Ni and Ti–50.9 at.%Ni) which had the same diameter of 1 mm. The wires were welded with different parameters, including impulse width and welding current. The aim was to assess the influence of the laser-welding process on the microstructure and mechanical properties of the welded joint ...

Different methods have been applied to refine various characteristics of the zone (or nugget) obtained by friction stir welding (FSW). In the current research, joining components are vibrated normal to the weld line during FSW to refine the zone microstructure. This process is described as friction stir vibration welding (FSVW). The effect of FSVW on mechanical properties, corrosion behavior, a...

We have previously reported on the development of explosively formed fuse (EFF) opening switches for use in applications where very long conduction times (lO's or lOG's p.s) are required and where opening times of 1-10 p.s are adequate. In this paper we report on the development of an EFF that allows magnetic flux in the switch to be delivered to the load rather than lost from the circuit. The ...

Flux tubes confined in tokamaks are observed to erupt explosively in some plasma disruptions and edge localized modes. Similar eruptions occur in astrophysical plasmas, for example, in solar flares and magnetospheric substorms. A single unifying nonlinear evolution equation describing such behavior in both astrophysical and tokamak plasmas is derived. This theory predicts that flux tubes rise e...

Ultrasonic impact treatment (UIT), which is a peening method, is usually used as a post-weld treatment in order to improve the fatigue strength of welded joints. In this study, fatigue tests were carried out on web-gusset welded joints treated by UIT and the results were compared with the fatigue lives of as-welded joints in order to examine the effects of UIT on the fatigue lives of welded joi...