Potential of High Compressive Ductility of Ultrafine Grained Copper Fabricated by Severe Plastic Deformation

Asano, Mayu
Yuasa, Motohiro
Miyamoto, Hiroyuki
Tanaka, Tatsuya
Erdoğan, Can
Yalçınkaya, Tuncay
Severe plastic deformation (SPD) can fabricate high-strength materials by forming an ultrafine grained (UFG) microstructure. Low elongation to failure of UFG materials in tensile tests, which has often been regarded as a measure of ductility of materials, has been attributed to low strain hardening of UFG structures where dislocation slip and its accumulation is very limited. In the present work, it is shown that the compressive extensibility of UFG materials can be comparable or potentially superior to that of annealed materials by using a parallel round-bar compression (PRBC) test which was designed for imposing an appropriate stress state preferable for high ductility using the shear mode. The high compressive extensibility of UFG materials can be a result of high accommodation of local strain incompatibility at non-equilibrium grain boundaries and a grain boundary-mediated deformation mechanism, which result in high damage tolerance against void formation and growth. Low strain rate sensitivity indicated that the superplastic viscous nature of deformation is not involved in the high compressive ductility of UFG materials using SPD.


Numerical Analysis of a New Nonlinear Twist Extrusion Process
Yalçınkaya, Tuncay; Miyamoto, Hiroyuki; Yuasa, Motohiro (MDPI AG, 2019-5-1)
Severe plastic deformation (SPD) can produce ultrafine grained (UFG) and nanocrystalline (NC) materials by imposing intense plastic strain. One of the many options for inducing large plastic strains is to pass the material through a torsional/twist extrusion. The high-strength materials fabricated by SPD has no limit in dimension, and they can even be applied to load-carrying structural materials. Even though the method is quite successful, the industrial transfer has been limited so far because of low prod...
Efficient fabrication of ultrafine-grained 316L stainless steel surfaces for orthopaedic applications
Tufan, Yiğithan; Efe, Mert; Ercan, Batur (Informa UK Limited, 2019-10-13)
Commonly used severe plastic deformation (SPD) methods are suitable for fabrication of bulk nano and ultrafine-grained metals. Drawbacks of these methods include durability of dies, geometrical restrictions and reduced ductility of the products. In this study, two common machining techniques used in manufacturing of orthopaedic components, turning and milling, were applied on 316L stainless steel as surface SPD to refine the surface microstructures of the workpiece. Machining with optimised parameters resul...
Investigating the effects of hardening of aluminium alloys on equal-channel angular pressing-A finite-element study
Karpuz, P.; Simsir, C.; Gür, Cemil Hakan (Elsevier BV, 2009-03-15)
Equal-channel angular pressing (ECAP) is a promising severe plastic deformation method for production of ultrafine-grained bulk metals and alloys with considerably improved mechanical properties. In this study, numerical experiments were carried out to investigate the effect of strain hardening of aluminum alloys on the process performance of ECAP via finite element modeling. In the constitutive model, isothermal-plane strain, frictionless condition was assumed. The numerical results showed that strain hard...
Homogenization of ECAPed Al 2024 alloy through age-hardening
KOTAN, G.; TAN, E.; Kalay, Yunus Eren; Gür, Cemil Hakan (2013-01-01)
Mechanical properties of aluminum alloys can be improved by obtaining ultra-fine grained structures via severe plastic deformation methods such as equal channel angular pressing (ECAP). In practice, however, the final structure may not be as homogeneous as desired. Thus, elimination of the inhomogeneity of ECAPed samples is a challenging task. In the case of age-hardenable alloys, a combination of ECAP and aging might provide new means of obtaining microstructural homogeneity. In this study, the effect of p...
Long-term thermal stability of Equal Channel Angular Pressed 2024 aluminum alloy
TAN, Guher; Kalay, Yunus Eren; Gür, Cemil Hakan (2016-11-20)
The strength of bulk metallic materials can be improved by creating ultra-fine grained structure via severe plastic deformation (SPD). However, the thermal stability of severely deformed materials has been a major issue that restricts their practical use within the industry. Although there are studies on the thermal stability of SPD metals, the long-term annealing response of particularly complex alloys, such as the age hardenable ones, remains undetermined. In the present study, annealing behavior of the s...
Citation Formats
M. Asano, M. Yuasa, H. Miyamoto, T. Tanaka, C. Erdoğan, and T. Yalçınkaya, “Potential of High Compressive Ductility of Ultrafine Grained Copper Fabricated by Severe Plastic Deformation,” METALS, pp. 0–0, 2020, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/69588.