Aluminum Alloys, Processing and Characterization: Alloy and MMC Development
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Dimitry Sediako, University of British Columbia
Monday 2:00 PM
March 15, 2021
Room: RM 27
Location: TMS2021 Virtual
Session Chair: Dimitry Sediako, University of British Columbia
2:00 PM
Introductory Comments: Aluminum Alloys, Processing and Characterization: Dimitry Sediako1; 1University of British Columbia
Introductory Comments
2:05 PM Invited
Anodization Compatibility of Eutectic Aluminum-Cerium Alloys: Zachary Sims1; David Weiss2; Hunter Henderson3; Orlando Rios4; Jiheon Jun5; Sur Debashish6; Max Wiener7; Ryan Ott8; Fangqiang Meng8; 1University of Tennessee; 2Eck Industries; 3Lawrence Livermore National Laboratory; 4University of Tennessee Knoxville; 5Oak Ridge National Laboratory; 6University of Virginia; 7Auto Anodics; 8Ames Laboratory
Anodizing is the most common method for producing corrosion resistant conversion coatings for aluminum alloys. It is possible to use anodizing with most commercial aluminum alloys to increase material corrosion resistance, but often the brittle, passive oxide layer formed during anodization does not adhere well to the material reducing effectiveness and overall compatibility. Therefore, it is important for the compatibility and effect of anodization to be studied for any newly developed alloys. Eutectic Al-Ce alloys are a recent discovery and offer great advantages for producing economic high-temperature alloys for next generation applications. Anodizing of Al-Ce alloys shows good compatibility with current processes and may exhibit novel passivated layer adhesion properties whereby intermetallic phases anchor the anodized product to unconverted bulk. The source of these properties and their effect on material corrosion and layer adhesion properties of Al-Ce alloys will be discussed and compared with results from common commercial aluminum alloys.
2:35 PM
Al-Sm Alloys Under Far-from-Equilibrium Conditions: Can Okuyucu1; Burçin Kaygusuz1; Cemil Işıksaçan2; Onur Meydanoglu2; Amir Motallebzadeh3; Sezer Özerinç1; Yunus Kalay1; 1Middle East Technical University; 2Assan; 3Koç University
Traditional Al alloys have shown tremendous potential in the aerospace industry due to its attractive properties such as ductility, fracture toughness, and fatigue resistance. However, modern aerospace applications call for next-generation Al alloys with a stringent combination of properties such as high strength, low density, and excellent environmental stability. In that sense, we studied highly driven Al-Rare-Earth (RE) alloys under far-from-equilibrium conditions to investigate the possible effects of cooling rate on the expected microstructure, thus mechanical properties. Al94Sm6 was produced using a copper wheel melt-spinner. XRD analysis showed the Sm is entirely trapped within the Al matrix. The heat-treated specimens resulted in the formation of the nanocrystalline Al4Sm phase embedded in the Al matrix, with a two-step precipitation sequence. The hardness values determined by nanoindentation shows that the initial supersaturated solid solution has 3.83 GPa hardness, while the heat-treated ones have 3.34 GPa. The mechanisms behind this extreme strength and ductility through solute trapping and subsequent heat-treatments were discussed in detail using a combined study of micromechanical characterization, electron microscopy, XRD, and DSC.
2:55 PM
Effect of Minor Additives to Al-Zn-Mg Alloys on Welding and Corrosion Performance for Building Constructions: Alexander Gradoboev1; Dmitriy Ryabov1; Viktor Mann2; Aleksandr Krokhin2; Roman Vakhromov1; Anna Ivanova1; Anton Legkikh1; 1Light Materials and Technology Institute LLC; 2RUSAL Management JSC
Al-Zn-Mg alloys are common structural materials used in building constructions for their high specific strength and good weldability. The limiting factor in the use of these alloys in welded structures is their tendency to exfoliation corrosion and to stress corrosion of both the base metal and especially the welded joint. Meanwhile there are some possibilities to improve stress corrosion cracking susceptibility by different approaches including heat treatment and microalloying. The influence of minor additives of transition metals, including rare-earth metals, on the mechanical properties and corrosion resistance of extruded semi-products and welded joints obtained by MIG welding was investigate. The present study also shows the influence of heat treatment conditions on the tendency to stress corrosion of extruded semi-products of Al-Zn-Mg alloys and their welded joints. It is shown that the balanced additives can lead to significant improvement in the characteristics of weld joints.
3:15 PM Cancelled
Mechanism Behind Al/Cu Interface Reaction: The Kinetics and Diffusion of Cu in Forming Different Intermetallic Compounds: Yongqiong Ren1; Jie Chen1; Bingge Zhao2; 1Yonggu Group Corporation Co., Ltd.; 2Shanghai University
The dissimilar welding of Al/Cu is widely used in power industry system because it realizes satisfying mechanical and electrical property with low cost. As the key factor influencing the property of welds, the formation of Al/Cu intermetallic compounds has attracted much attention. In this study, liquid-solid reaction between Al and Cu was realized at different temperatures, producing various IMCs. With morphology observation, the dependence of IMC formation on reaction temperature was determined. As the diffusion of Cu was taken into consideration, the inner kinetics was discussed. Moreover, with the aid of focused ion beam (FIB) and high-resolution transmission electron microscopy (HRTEM), the phase transformation of IMCs and its mechanism of IMCs was illustrated. c
3:35 PM
Phase Formation of Mo- and Cr-rich Compounds in an Al-Si Cast Alloy: Peer Decker1; Jan Steglich1; Anna-Lena Kauws1; Andreas Kiefert1; Luisa Marzoli1; Marcel Rosefort1; 1Trimet Aluminium SE
Ongoing development of Al-Si cast alloys leads to an increased usage of alloying elements to fulfill different property demands. This new complexity of composition may lead to the formation of various phases, of which some are desired and others unwanted. In the present case, a model Al-Si alloy was developed on a laboratory scale and analyzed. The idea behind the alloy was to reduce die sticking while increasing its mechanical properties by adding the transition metals Cr, Mn, and Mo. Special attention was given to the formation of phases rich in the above mentioned elements. During permanent mold experiments, an unintended formation of a phases rich in the added elements was discovered. Recommendations on how to avoid the formation of this phase are given as well.
3:55 PM
Understanding the Effect of Quench Delay and Alloy Chemistry on Various 6000 Series Alloys Systems
: David Shoemaker1; Robert Matuska1; 1Kaiser Aluminum
It is well known that the strengthening of 6000 series aluminum can be achieved via billet heating, direct extrusion and subsequent water or air quenching. The metallurgical characteristics of the Al-Mg-Si alloy system renders it relatively quench insensitive thus allowing billet preheats and the heat of extrusion to substitute for a separate, more expensive solution heat treat step. However, the linkage of direct extrusion to the quench comes with a risk of quench interruptions that, under certain conditions, can reduce the localized strength of the extrusion. These localized areas reduce the consistency in performance and therefore it is desirable to minimize the strength variation that result from these events. The work presented in this paper is intended to better understand two key inputs to these quench interruptions (quench delay time and alloy chemistry) with the goal of making the process more robust and therefore less sensitive to quench delays.
4:15 PM
Effect of Heat Treatment on the Microstructure and Mechanical Properties of LB-PBF AlSi10Mg and Scalmalloy: Shaharyar Baig1; Seyed Ghiaasiaan1; Nima Shamsaei1; 1Auburn University
Laser beam powder bed fusion (LB-PBF) process is an attractive additive manufacturing (AM) technology applicable for numerous metallic alloying systems. AlSi10Mg and Scalmalloy are two of aluminium alloys are recently receiving a lot of of attention from AM processes. The test specimens for this study were produced using LB-PBF technology on an EOS 290 machine. The objective of the study the effect of heat treatments on microstructure and mechanical properties of both LB-PBF aluminium alloys. The microstructural study was carried out using both hardness measurements and optical microscopy. Hardness testing was performed by Instrumented Indentation Testing standard using Anton Paar NT2 machine. Furthermore, uniaxial tensile properties of both of AM LB-PBF aluminium alloys were measured in various heat-treated conditions.
4:35 PM
Thermal Properties of Hybrid Al-Cu-Components Produced by Combining Powder Pressing and Semi-solid Forming Strategies: Marco Speth1; Mathias Liewald1; Kim Rouven Riedmueller1; 1Universtiy of Stuttgart, Institute for Metal Forming Technology
Hybrid material structures offer the possibility of combining different material properties and thus meeting diverse functional requirements in one single component. Here, particular attention must be paid to the transition zones between the metallic compound partners. These transition zones need to show homogeneous and materially bonded structures to ensure ideal transmission of material properties and to prevent component failure due to material defects. In this respect, an innovative process for producing hybrid components has been developed in which a powder metallurgical route is combined with semi-solid forming technology. The aluminium alloy AlSi7Mg0.6 (A357) is heated into the semi-solid state and subsequently formed onto a porous copper green body. In order to analyse the connection mechanisms, copper green bodies of varying densities were used, resulting in different joints of the components. The paper deals with thermal properties of components produced in this way.
4:55 PM Question and Answer Period Dr. Dimitry Sediako