Mechanical Properties and Microstructural Evolution of CuZn Alloys via Pre-Torsional Deformation

Abstract

Mechanical properties and microstructural evolution of Cu-10wt.%Zn and Cu-30wt.%Zn alloys after pre-torsional deformation have been investigated in this study. The results indicated that pretorsional deformation can significantly enhance the strength of both Cu-10wt.%Zn and Cu-30wt.%Zn alloys without changing their shape and size, but with the sacrifice of the ductility. The pre-torsion deformation can introduce gradient hardness and microstructures along the radial direction, with the microstructures along the radial direction in Cu-30wt.%Zn alloy being "dislocations→stacking faults→twins (low density)". The stacking fault energy affects significantly the microstructure along the radial direction.

Effects of Angle and Rate of Twist via Pre-Torsional Deformation on Tensile Properties and Hardness of Hot-Rolled, Low-Alloy Steel Rods

“…The hardening effects via severe plastic deformation such as pre-torsional deformation are originated from either or both of the following 2 strengthening mechanisms: (i) strain hardening (ii) grain-size strengthening. Though both mentioned mechanisms enhance strength and hardness through hindering dislocation motion, strain hardening is a result of the dislocation accumulation and entanglement within the grains' interior during plastic deformation while grain-size strengthening utilizes an increase in grain boundaries after grain-size reduction through grain refinement [11,21]. Since the average grain sizes were uniform throughout the specimens in the radial direction and the differences in the average grain size among all pre-torsional conditions were statistically insignificant, it is concluded that the principal strengthening mechanism involving pre-torsional deformation of hotrolled SCM415 steel is strain hardening.…”

Evaluation of Dihedral Angle Twin Boundaries in Cu10 wt%Zn Alloy Using Atomic Force Microscopy

“…Knowledge of interfacial energy values may be necessary when solving microstructural or metallurgical challenges in demanding the industrial applications of commercial CuZn alloys where the combinations of strength, machinability, and corrosion resistance are required (Zhao et al, 2007;Zhang et al, 2008;Igelegbai et al, 2017;Choucri et al, 2019;Gu et al, 2019;Zaynullina et al, 2019). Nucleation, growth, and coarsening of precipitates (Lifshitz & Slezov, 1961;Wagner, 1961) or grain growth, mobility, and recrystallization (Shockley & Read, 1949;Herring, 1951) are at the heart of end-user mechanical properties such as hardness, strength, and ductility.…”

“…It has been reported that strengthening mechanisms have proven to work for micro-and macro-grained metals and alloys operate with some modifications in nanocrystalline materials (Scattergood et al, 2008). Grain boundaries, the presence of grain boundaries segregates, stacking faults, and twins appear to play a unique role in terms of plastic deformation mechanisms and have an effect on mechanical properties (Gu et al, 2019;Zaynullina et al, 2019).…”