Aluminum Alloys, Processing and Characterization: Material Processing and Modeling
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Dimitry Sediako, University of British Columbia
Tuesday 8:30 AM
March 16, 2021
Room: RM 27
Location: TMS2021 Virtual
Session Chair: Eric Taleff, University of Texas
8:30 AM
Simulations of Wear-induced Microstructural Evolution in Nanocrystalline Aluminum: Yeqi Shi1; Izabela Szlufarska1; 1University of Wisconsin-Madison
Friction, wear resistance, and microstructural evolution of nanocrystalline (NC) aluminum during sliding were investigated using molecular dynamics simulations. The effect of dopants and twinning has also been explored and it was found that doped NC Al sample and twined NC Al sample exhibited better wear resistance and smaller friction force than pure NC Al sample. This trend was found to be correlated with higher hardness and higher strength of the doped NC Al sample and twined NC Al sample. We have determined the mechanisms of grain growth in NC Al and the main mechanism is grain boundary (GB) migration induced by emission of dislocations. Additional grain growth mechanisms found in the pure NC Al samples are disconnection-mediated GB migration and a so-called dissociation of low-angle GBs. Dislocation emission was suppressed in both doped and twined samples.
8:50 AM
High-throughput Aluminum Alloy Discovery Using Laser Additive Manufacturing: Qingyu Pan1; Monica Kapoor2; Sean Mileski2; John Carsley2; Xiaoyuan Lou1; 1Aubrun University; 2Novelis Global Research and Technology Center
The current alloy development cycle of Aluminum alloys is lengthy and costly. This study evaluates the feasibility of using combinatorial materials synthesis and compositionally graded specimen design to accelerate the Al alloy discovery. The high-throughput exploration of the compositional space was enabled through an integrated experimental approach involving powder mixing and laser direct energy deposition additive manufacturing (AM). The concept was demonstrated in (1) Al-Mn binary alloys and (2) Al 3104 alloy, with the benchmarking against their cast counterparts. The research highlights the difference between AM and as-cast Al alloys, including grain structure, defect formation, second-phase particles, and mechanical properties. Besides the effects of alloy composition, the distribution and size of second-phase particles and their influences on the recrystallization during homogenization and rolling heat treatment were studied in detail. It suggests that the laser AM can develop a valid dataset to support the high-throughput material screening for Al alloys.
9:10 AM
Manufacturing A206 Aluminum Alloy by Step Sand Casting: Effect of Solidification Time on Mechanical and Surface Properties of the Cast Samples Using Experimental and Simulation Results: Amir Kordijazi1; Pradeep Rohatgi1; 1University of Wisconsin Milwaukee
In the present study, the effect of section size and solidification time on the grain size, hardness, contact angle (CA), and corrosion resistance of A206-T7 aluminum alloy was investigated. A step casting, with varying section thickness (0.25, 0.5, 0.75, and 2.0 inches) was made in a sand mold. Casting simulation showed a quantitative increase in solidification time with section thickness. The experimental results indicate that by increasing casting thickness from 0.25 inches to 2 inches, the average grain size increases from 80 µm to 124 µm. Wetting study shows that water CA values for different section sizes range between 71 to 87 degree. It was found that the corrosion current nearly decreases by 73% when section thickness increases from 0.75 to 2 inches suggesting that the dominant corrosion mechanism in this alloy is intergranular corrosion.
9:30 AM
Experimental and Numerical Examinations Regarding the Material Flow of Combined Rolling Extrusion Process: Christoph Heinzel1; Aleksandr Salnikov2; Sören Müller3; 1SMS Group GmbH; 2RUSAL; 3FZS - TU Berlin
The combination of the conventional forming processes rolling and extruding enables the continuous production of cross-sectional aluminum long products. Due to its continuity, the combined forming process is more efficient compared to its conventional alternatives. This paper describes the results of numerical and experimental investigations regarding the material flow of the combined rolling and extrusion process. The finite elements method was used to simulate the material flow within the process. The simulated results were compared to an experimental visio-plastic examination of the process.The results of the visioplastic examination show some specific material flow characteristics linked to the combined rolling and extrusion process. The results of the numerical simulation and the experi-mental investigations are in good agreement. The finite elements method can be used to reproduce the material flow within the examined process and its specifics.
9:50 AM
Comparison of Simulation and Real Life to Set Up Holistic Approach for Extrusion Process: Zeynep Tutku Ozen1; Mehmet Buğra Güner1; Osman Halil Çelik1; Görkem Özçelik1; Murat Konar1; Turgay Güler1; Cem Mehmetalioğlu1; Mustafa Serkan Özcan1; Tolga Demirkıran1; 1ASAS
6xxx series aluminium alloys are used in various sectors ranging from automotive industry to structural applications. Wide range of usage areas requires different materials characteristics. In order to meet customer requirements, R&D activities should be conducted in industrial environment. Development studies can be managed with computer aided simulation techniques first to reduce number of trials which negatively affects productivity. In this study, simulation and modelling have been utilized to develop an holistic approach for forcasting critical performance characteristics without committing excessive experiments. At the same time, verification of real life outputs were also carried out within the scope of the study.
10:10 AM
Computational Simulation of Nanoparticle Distributions in Metal Matrix Composite Casting Processes: Gongyuan Zheng1; Juergen Jakumeit1; Thomas Pabel2; Christian Kneissl2; Luca Magagnin3; 1ACCESS e. V.; 2Austrian Foundry Research Institute (OGI); 3Politecnico di Milano
Lightweight metal matrix nanocomposites (MMnC) could offer distinct advanced properties to light metals due to inherent high temperature stability, high strength, high stiffness and wear resistance. Production processes have to consider that the movement of particles in the nanoscale range differs from that in the micro and mesoscale range. Nanoparticles show a slight aggregation behaviour in the casting process compared to larger particles. Here a Lagrangian framework was developed to calculate the conservation equation of momentum for nanoparticle taking into account surface and body forces that act on the particle. Thermophoretic and Brownian forces which play a dominant role for the motion of nanoparticles were implemented to analyse the distribution of nanoparticles in low pressure die casting simulations. Strategies to simulate nanoparticle tracking in low pressure die casting were proposed. Verifications were carried out to investigate the motion behaviors using benchmark simulations. The developed model was employed to conduct low pressure die casting simulation and the computational simulation of nanoparticle distributions could be utilized to compare to experimental results from low pressure die casting processes determined by transmission electron microscopy.
10:30 AM
Effect of Thermomechanical Processing on Strengthening of the 5181 Alloy (with 0.03 %Sc) Sheets for Preservation of 40 % Improved Strength Compared with 5083: Dmitry Fokin1; Aleksandr Alabin2; Sergey Valchuk2; Viktor Mann2; Aleksandr Krokhin2; 1Light Materials and Technologies Institute UC RUSAL; 2JSC RUSAL Management
The aim of the paper is to determine regimes of thermomechanical processing of the 5181 alloy (Al-Mg-Sc system with 0.03%Sc) for preservation of 40% improved strength compared with 5083. The influence of cold work degree in the range of 30 - 70% and annealing regimes on mechanical properties of the 5181 sheets is investigated. The condition for achieving the required strength advantage over 5083 alloy is to ensure partially un-recrystallized structure in the 5181 sheets. It is shown that cold work degree has a significant effect on the recrystallization rate during annealing. With a decrease of the cold work degree, the softening of 5181 sheets shifts towards the areas of higher annealing temperatures and the softening curve becomes more flattened. This allows precise control of the high strength-elongation balance. Preferable fields of application for 5181 alloy are marine and automotive applications due to attractive combination of strength properties and cost.
10:50 AM Question and Answer Period