CFD-enhanced description of local viscous flow through expansion equal channel angular extrusion geometric domain

ABSTRACT

The continuing development of new deformation schemes for material pressure forming resulted in the appearance of new technological process of Expansion Equal Channel Angular Extrusion (Exp-ECAE), which was proposed by Sepahi-Boroujeni and Fereshteh-Saniee in 2015. The present original research is a novel approach to an alternative hydrodynamic study of the Exp-ECAE deformation scheme with wide use of the numerical techniques of computational fluid dynamics (CFD). Additional mechanical degrees of freedom (DOFs) for Exp-ECAE die tooling equipment were first introduced by accounting for the dynamic effects of independent translational motion of the external movable walls of an Exp-ECAE angular domain. The proposed novel paper provides the possibility for original engineering-friendly visualisation of dead zone formation in the process of Exp-ECAE pressure forming. Multiple results of CFD-based numerical modelling show new promising ways for engineering minimisation of dead zone areas through alternative triggering of different DOFs of Exp-ECAE die tooling resulting in independent transport motion of the external walls of an Exp-ECAE angular domain.

Abbreviation: SPD is Severe Plastic Deformation; ECAE is Equal Channel Angular Extrusion; Exp-ECAE is Expansion Equal Channel Angular Extrusion; CFD is computational fluid dynamics; DOF is degree of freedom.

KEYWORDS:

• Equal channel angular extrusion
• expansion equal channel angular extrusion
• angular domain
• angular die
• CFD
• viscous flow
• finite difference

Authors’ contributions

All authors participated in the design of this work and performed equally. All authors read and approved the final manuscript.

Competing interests

The authors declare that they have no competing interests.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data Availability

The data used to support the findings of this study are included within the article.

Additional information

Funding

The authors have no funding to report.