Micro-structural Evolution in Metals Subjected to Simple Shear by a Particular Severe Plastic Deformation Method

Abstract

Simple shear (SS) has been considered an optimal deformation method of severe plastic deformation (SPD). To achieve SS, a particular SPD method known as mutative channel torsion extrusion (MCTE) was designed based on the geometric equivalence of SS, and the cavity parameters of a die were calculated according to strain equivalence. To investigate the characteristics of micro-structural evolution subjected to MCTE, simulated and experimental investigations were conducted. The simulated results indicate that equivalent strain distribution on the cross section is relatively uniform, and the metallographic observations confirm the simulated phenomenon. Transmission electron microscopy investigations show that the process of grain refinement undergoes the formation of shear bands, dislocation cells, dislocation forests, largeangle grain boundaries, and recrystallization nuclei. Two types of mechanisms are proposed in view of the different effects of SS on grain refinement. Eventually, MCTE is ensured as an effective method for grain refinement.

Severe Plastic Deformation of Fe-22Al-5Cr Alloy by Cross-Channel Extrusion with Back Pressure

“…Furthermore, the application of BP reduces the amount of waste material. Li et al [46] used BP to achieve a full filling by the material during its extrusion through the die with a helical deformation zone in a mutative torsion extrusion channel method (MCTE).…”

Simple shear extrusion as an efficient severe plastic deformation technique: A review

“…SSE has been partially reviewed and discussed in the literature, mostly in terms of comparison between different SPD techniques [34][35][36][37][38][39][40]. However, this technique and its variant, CSSE, pose several distinctive features that are thus far published in separate articles.…”