Vortex extrusion (VE) is a severe plastic deformation technique which is based on the synergies between high strain accumulation and high hydrostatic pressure. Such a high amount of pressure, places a mandate to seek the method for investigation of the load under processing conditions. For this, kinematically admissible velocity field and upper bound terms based on Bezier formulation are develo...

Twist extrusion process is a rather new route to produce highly strained materials. In this process, severe plastic deformation is applied by large shear strains. In current article, required energy for twist extrusion by use of admissible velocity field together with the upper bound technique is predicted. The proposed model is capable of considering the effect of various parameters such as di...

The present paper deals with numerical comparison of two twist-based severe plastic deformation processes: (i) the elliptical cross-section spiral equal-channel extrusion (ECSEE) proposed recently as a novel process and (ii) the classical twist extrusion (TE). ECSEE was developed in attempt to process cylindrical work pieces and to generate more uniform strain distribution compared to classical...

The aim of the present study is to determine the feasibility of making a rectangular twist waveguide used to rotate electromagnetic waves. For this purpose, the process of fabricating an aluminum rectangular twist waveguide was simulated by making use of finite element method and Deform software. The optimum length and angle of the twist die for manufacturing a twist waveguide with inner cross ...