General Poster Session: Light Metals
Program Organizers: TMS Administration
Monday 5:30 PM
February 24, 2020
Room: Sails Pavilion
Location: San Diego Convention Ctr
F-62: Effect of Heat Treatment on Bending Performance of Extruded 6082 Aluminum Alloy T Profiles: Mehmet Bugra Guner1; Osman Halil Çelik1; Mert Altay1; Cem Mehmetalioğlu1; 1ASAS Aluminium
6xxx series aluminum alloys have been widely used in automotive and trailer industry for 10 years. 6060, 6063, 6005A, 6061 and 6082 alloys are the most used alloys in these sectors. In trailer industry, high strength and bending performances are desired due to cold deformation of the profiles while assembling the parts. For this reason 6082 aluminum alloy has a significant role. In this study, for investigating the effect of different heat treatment temperatures and times applied after extrusion process on bending performance of AA 6082 alloys, various experiments were conducted. Five different aging temperatures (160 – 200 °C) and six different aging times (2 – 12 hours) parameters were utilized. Optical microscope and energy dispersive spectrometer equipped scanning electron microscope were used for structural analyses and bending test was used for investigating bending performance of the samples.
Cancelled
F-65: Screw Gradient Continuous Casting and High-Throughput Characterization: Jingyuan Li1; 1University of Science and Technology Beijing
High throughput preparation is the core of high-throughput experimental technology. A novel high-throughput method, screw gradient continuous casting (SGCC) is proposed in this study. By means of this method, Al-(0~15)Zn-(0~5)Mg-(0~5)Cu alloy bars with gradient distribution of composition along the axial direction, diameter and length of which are 30mm and 500mm, were prepared in this paper. Additionally, the standard compositions of type 7136, 7056 and 7055 aluminum alloys were contained in the bars. The homogenization and aging heat treatment of the gradient bars were completed. Then distribution of chemical composition, hardness, conductivity, corrosion resistance of the gradient bars was characterized by high-throughput methods. The results show that the composition, microstructure and properties of gradient bars are basically consistent with those of commercial aluminum alloy. It can be concluded that fast preparation and screen of new materials can be achieved by the screw gradient continuous casting method.
F-64: Pyramidal <c+a> Cross-slip Mediated Ductility in Mg Alloys: Rasool Ahmad1; Zhaoxuan Wu2; William Curtin1; 1EPFL; 2City University of Hong Kong
Solute accelerated cross-slip of <c+a> dislocation from low-energy pyramidal II to high-energy pyramidal I plane has recently been discovered as critical in encouraging pyramidal <c+a> slip and enhancing ductility in certain solid solution Mg alloys. Favorable solutes, e.g. rare-earth elements, Ca, and Mn, reduce the cross-slip barrier by lowering the pyramidal I-II screw dislocation energy difference. Increasing the solute concentration can cause pyramidal I to become more stable than pyramidal II, modifying the cross-slip behavior and energetics. As pyramidal I becomes increasingly favorable, cross slip becomes difficult and the alloy may lose ductility. Here, the double cross-slip mechanism of <c+a> dislocation, when pyramidal I has lower energy than pyramidal II, is studied using transition path computations by employing a pure Mg MEAM potential. The mechanistic model of ductility is then extended to this regime and predicts an upper limit of solute concentration beyond which ductility of Mg alloy will deteriorate.