Effect of Cyclic Pre-deformation on Uniaxial Tensile Behavior of Cu-16 at. pct Al Alloy with Low Stacking Fault Energy

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Physical metallurgy and materials science, 2017-02, Vol.48 (2), p.678-684
• Main Authors: Yan, Y., Qi, C. J., Han, D., Ji, H. M., Zhang, M. Q., Li, X. W.
• Format: Article
• Language: English
• Subjects: Alloys; Aluminum; Aluminum base alloys; Characterization and Evaluation of Materials; Chemistry and Materials Science; Dislocations; Energy; Materials Science; Materials selection; Mechanical properties; Metallic Materials; Nanostructure; Nanotechnology; Polycrystals; Slip; Stacking fault energy; Strengthening; Structural Materials; Surfaces and Interfaces; Tensile strength; Thin Films
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-016-3891-y

To explore the effect of cyclic pre-deformation on static mechanical behavior of materials with different stacking fault energies (SFEs), polycrystalline Cu-16 at. pct Al alloy with a low SFE is selected as the target material in the present work, and the strengthening micro-mechanisms induced by cyclic pre-deformation are compared with the previous studies on pure Al with a high SFE and Cu with an intermediate SFE. The results show that the movement of dislocations exhibits a high slip planarity during cyclic pre-deformation at different total strain amplitudes Δ ε t /2, and some nano-sized deformation twins are formed after subsequent tension. The cyclic pre-deformation at an appropriate Δ ε t /2 of 1.0 × 10 −3 promotes a significant increase in ultimate tensile strength σ UTS nearly without loss of tensile ductility, which primarily stems from the introduction of many mobile planar slip dislocations by cyclic pre-deformation as well as the formation of nano-sized deformation twins during subsequent tension. Based on the comparison of the strengthening micro-mechanisms induced by cyclic pre-deformation in Al, Cu, and Cu-16 at. pct Al alloy, it is deduced that a low-cycle cyclic pre-deformation at an appropriate condition is expected to cause a better strengthening effect on the static tensile properties of low SFE metals.