Ultrafine-Grained Materials Fabrication with High Pressure Torsion and Simulation of Plastic Deformation Inhomogeneous Characteristics

Abstract

Utilization of severe plastic deformation (SPD) methods has provided a convenient approach for producing ultrafine-grained (UFG) materials exhibiting outstanding characteristics especially mechanical properties. HPT as one of the SPD methods can lead both to smaller grains and to a higher fraction of high-angle grain boundaries, which is an especially attractive procedure by researchers. In order to understand the nonlinearities relationship between the mechanical properties and the developed strain during plastic deformation, local deformation analysis using the finite element methodwas applied for the HPT process. In this chapter, results are reported of an investigation on the deformed microstructure and mechanical properties of different materials samples during the HPT process using experiments and FEM simulations. Simulation results indicate that the disks show inhomogeneity development and distribution of strain and stress during the plastic deformation. Microstructure and hardness investigation results can give a well support to verify the rules of inhomogenous plastic deformation in the early stage of the HPT disks. Furthermore, the friction and anvil geometry play important roles in the homogeneity of the deformation. After the hollow cone high pressure torsion (HC-HPT), the thermal stability of Zr 64.13 Cu 15.75 Ni 10.12 Al 10 BMGs is enhanced, while the elastic modulus of BMG will be decreased.

Finite element analysis of plasticity behaviour of aluminium alloys in high-pressure torsion compressive loading stage

“…High-pressure torsion (HPT) simulation using finite element method (FEM) is getting more attention since the past few years (Kulagin et al, 2017;Larijani et al, 2015;Song et al, 2017). It provides the ability to analyse stress and plastic strain evolution thoroughly across the sample dimension with increased loading (Lee et al, 2012;Michael Shockley et al, 2017).…”