Microstructure Evolution and Mechanical Properties of Al-1080 Processed by a Combination of Equal Channel Angular Pressi
- PDF / 1,346,300 Bytes
- 10 Pages / 593.972 x 792 pts Page_size
- 106 Downloads / 202 Views
TRODUCTION
METALLIC materials with a nanometer or submicrometer grain size have received much attention in the past decade because of their unique mechanical and physical properties and high performance.[1] Severe plastic deformation (SPD) is one of the most promising techniques for producing ultrafine-grained (UFG) or nanocrystalline (NC) materials. Equal channel angular pressing (ECAP)[2–6] and high pressure torsion (HPT)[7–10] are two of the most widely applied processes among various SPD processes.[11–14] The principles of ECAP and HPT have been discussed in detail in previous works.[11–13] Furthermore, numerical simulations of both SPD processes have been performed successfully using the finite element method (FEM).[15,16] Recently, applications of ECAP or HPT have been performed to investigate the microstructure and mechanical properties of commercially pure Ti, high purity Ni, and pure Cu.[17–21] It was observed that HPT processing of the ECAP-processed sample produces more refined microstructures in Ti and Ni.[17–20] Recently, Lugo et al.[21] reported that Cu processed by combined ECAP + HPT shows a significant increase in grain size
due to the effect of heat generation during the HPT process and improved tensile strength. On the other hand, the most homogeneous grain size distribution was observed in the ECAP + HPT-processed specimen. Al and its alloys are used widely in the automotive and aircraft industries due to their light weight.[22,23] The production of Al and Al alloys with UFG microstructures, which lead to significant improvement in the mechanical properties, has been an important focus of research in the structural material community. Previous works have investigated the effects of plastic deformation with use of only the ECAP or HPT process on the evolution of microstructure and on the mechanical properties of Al and its alloys.[24–29] However, there have not been further investigations on the effects of a combination of ECAP and HPT on the evolution of the microstructure and on the mechanical properties of Al and its alloys. The present research was performed in order to investigate the effect of different SPD (ECAP, HPT, and ECAP + HPT) processes on the evolution of the microstructure and on the mechanical properties of Al-1080.
II.
MOHAMED IBRAHIM ABD EL AAL, Lecturer, is with the Mechanical Design and Production Department, Faculty of Engineering, Zagazig University, Zagazig, Egypt. EUN YOO YOON, Postdoctoral Research Associate, and HYOUNG SEOP KIM, Professor, are with the Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea. Contact e-mail: [email protected] Manuscript submitted July 26, 2012. Article published online February 5, 2013 METALLURGICAL AND MATERIALS TRANSACTIONS A
EXPERIMENTAL
Al-1080 ingots with an initial grain size of 470 ± 2 lm and a chemical composition as indicated in Table I were used in the present study. The Al-1080 ingots were machined to cylinders of 15 mm diameter and 80 mm length for ECAP.
Data Loading...
