Aluminum Alloys, Characterization and Processing: Characterization and Processes
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Julie Levesque, Quebec Metallurgy Center; Stephan Broek, Kensington Technology Inc
Tuesday 2:30 PM
March 21, 2023
Room: 32A
Location: SDCC
Session Chair: Etienne Martin, École Polytechnique
2:30 PM
Characterization of Aluminium Conductors Steel Reinforced in Overhead Transmission Lines: Meysam Hassanipour1; Miguel Diago Martinez1; Denis Valiquette1; Fédéric Guay1; André Leblond1; 1Institut de Recherche d’Hydro-Québec
Extensive laboratory tests have been performed on 20 Aluminum Conductor Steel Reinforced (ACSR) conductors that were sampled from Hydro-Québec overhead transmission lines. Series of mechanical (tensile, torsion, wrap) tests along with metallographic analyses were carried out to reveal the mechanical properties and the remaining thickness of the coated zinc on steel strands. The age, geometry, current, and the type of environment corresponding to each ACSR conductor were considered to quantify the ageing and degradation behavior of conductors. It is shown that as the conductor ages, the zinc loss on steel strands triggers the decrease in mechanical properties. The aggressive environment induces a higher decrease in the remaining zinc thickness. However, a higher number of aluminum wire layers and diameters can retard this degradation. It was revealed that a low current transit through the wires might lead to higher degradation.
2:55 PM
Mechanical Properties and Electrical Properties of Permanent Mold Cast Eutectic Al-1.8Fe Alloy: Sufeng Liu1; Anita Hu1; Ali Dhaif1; Wutian Shen1; Hongfa Hu1; 1University of Windsor
A eutectic Al Alloy containing 1.8 wt% Fe (Al-1.8Fe) for electric vehicles was cast by using a permanent steel mold along with 99.7 pure Al %. The microstructure of the as-cast Al-1.8Fe alloy was analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The microstructure analyses revealed that the Al-1.8Fe alloy consisted of primary Al phase, eutectic Al phase, micron-sized eutectic Al-Fe phase, and nano-sized eutectic Al-Fe phase. The mechanical properties including ultimate tensile strength (UTS), yield strength (YS) and elongation (ef) were evaluated by tensile testing. The electrical conductivity was measured by the phase sensitive eddy current method. The addition of 1.8 wt% Fe increased both the UTS and YS of the cast pure Al significantly to 86.5 and 28.3 MPa from 34.5 and 12.3 MPa. However, the ef and electrical conductivity of the cast alloy decreased to 19.8% and 48.4 %IACS from 33.8% and 61.0 %IACS.
3:20 PM
Effects of the Friction Stir Welding Sliding and Sticking Mechanisms on the Microhardness, Texture, and Element Concentration: Nicholas Sabry1; Joshua Stroh1; Dimitry Sediako1; 1The University of British Columbia
Friction-stir-welding (FSW) has gained importance as an effective way to join dissimilar materials due to its solid-state nature. However, the effects of multiple parallel welds in the proximity of each other are poorly understood. In the current study, electron backscatter diffraction, microhardness, thermal conductivity, and differential scanning calorimetry were used to characterize the microstructure, hardness, and precipitate structure as a function of position in three parallel FSW between two aluminum alloys 6061 and A365 joined in a lap weld configuration. The results reveal the expected dynamically recrystallized, thermo-mechanical affected, and heat-affected zones with varying microhardness between the three welds corresponding to the maximum temperature reached for each weld. If the effects of minimum allowable distance between proximity solid-state welds are understood accurately, solid-state welds can be produced closer to each other with understood consequences, further optimizing the output material properties of the operation for a more comprehensive array of applications.
3:45 PM
Experimental Investigation of the Effect of High Temperature Shot Peening on the Surface Integrity of 7010-T7452 Aluminum Alloy: Abouthaina Sadallah1; Anindya Das1; Benoit Changeux2; Hong-Yan Miao1; Etienne Martin1; Sylvain Turenne1; Maxime Pauques1; 1École Polytechnique Montreal; 2Safran Tech.
The aluminum alloy 7010 is widely used in the aerospace industry due to its comparatively light weight and high strength. Shot peening is an important surface modification procedure for structural materials meant for improving the fatigue life. The surface properties can be further enhanced by changing the temperature of the surface during the process of peening. In this study, shot peening at room and at high temperatures ranging from 100°C to 300°C was performed at three Almen intensities: 0.10, 0.15, and 0.20 mmA, on cylindrical specimens of AA7010-T7452. The influence of the process on surface roughness, residual stresses, hardness, and microstructure was investigated. The results showed that the surface roughness increased with temperature of peening. An optimized peening temperature was identified from the variation of hardness and residual stresses. In-depth microstructural characterization of the surface after peening helped in understanding the surface integrity properties in greater detail.
4:10 PM Break
4:25 PM
Quality Assessment and Features of Microdrilled Holes in Aluminum Alloy Using Ultrafast Laser: Suman Chatterjee1; Abhijit Cholkar1; David Kinahan1; Dermot Brabazon1; 1Dublin City University
In this work, we present the use of a low power femtosecond laser system for the microdrilling of aluminum alloys. Hole sizes of 20 m were fabricated in arrays with sub-micron level precision in terms of diameter and hole location. The Design of Experiment approach was employed to analyse the influences of the laser power, frequency, and exposure time on the resulting quality of the produced micro-holes. The outputs measured were hole size, location and the variability in these measures. The metallurgical and geometrical features were examined using SEM, confocal microscope and laser surface profilometry. Processing throughput is also importance in industrial laser processes. The use of scanning optics and spatial light modulation (SLM) were examined as means towards developing a rapid and scalable ultrafast laser process. The timeframe for conventional galvanometer processing versus SLM processing were compared for different geometric array pattern (number and geometric arrangement of holes) production.
4:50 PM
Surface Characterization Methods to Evaluate Adhesive Bonding Performance of 6xxx Automotive Alloys: Greunz Theresia1; Martina Hafner1; Ralph Gruber2; Tomasz Wojcik3; Jiri Duchoslav4; David Stifter4; 1AMAG rolling GmbH; 2CEST Competence Centre for Electrochemical Surface Technology GmbH; 3Vienna University of Technology; 4Johannes Kepler University Linz
6xxx series aluminum alloys are increasingly used within the automotive industry due to their lightweight potential. For assembling several joining techniques are common. This paper focuses on adhesive bonding, which is widely employed but its mechanism is by far not fully understood. The sheet metal process, including hot and cold rolling, solution heat treatment, pickling and Ti/Zr conversion treatment, contributes heavily to the final bonding performance. Even minor changes in the rolling process may alter the surface near deformation layer or a variation during pickling can lead to unfavorable oxidic conditions. To evaluate these changes X-ray photoelectron spectroscopy (XPS), which is extremely powerful in gathering elemental, chemical and oxidic information from the topmost surface (<10 nm), was performed. Furthermore, transmission Kikuchi diffraction (TKD) in combination with a focused ion beam (FIB) preparation was employed to investigate the surface near grain structure. Additionally, scanning electron microscopy (SEM) provided valuable knowledge concerning the surface topography.
5:15 PM
Investigation of Resistance of Intergranular Attack for Various Heat Treated 2011 Alloys After Hard Anodizing: Ilyas Artunc Sari1; Gorkem Ozcelik1; Zeynep Tutku Ozen1; Onuralp Yucel2; 1ASAS Aluminum; 2Istanbul Technical University
Main alloying element of 2011 aluminum alloy is copper and it is disadvantageous from the point of corrosion compared to other aluminum alloys. 2011 alloy also contains bismuth and lead in their chemical composition. These elements have low melting point and enhance machinability of the alloy. In this way, 2011 alloys are frequently used in areas where machinability is important. In this study, 2011 aluminum billets were produced by direct chill (DC) casting and then homogenization was carried out. As the next step, billets were extruded. Different samples were taken from extruded profiles and heat treated to obtain T4, T6, T79, T73 conditions. Samples were then anodized. After anodizing, samples were taken to corrosive environment. Optical microscope, SEM and EDS were used for characterization and corrosion behavior of 2011 alloy under different heat treatment conditions was investigated. It was found that obtained experimental results agree well with expected properties.