Papers by Keyword: Aluminium Alloys

Abstract: Aluminium has become a cornerstone of sustainable architectural design due to its lightweight properties, structural strength, corrosion resistance, and high recyclability. However, its primary production remains energy-intensive and a major contributor to greenhouse gas (GHG) emissions. This study presents a comparative Life Cycle Assessment (LCA) of commonly used aluminium alloys in architectural components, evaluating them across key stages—production and end-of-life—based on energy consumption, emissions, and recyclability. The analysis covers 3000, 5000 and 6000-series alloys, as well as recycled, anodized, and coated variants. The study contributes a parameterized LCA-based framework to support sustainable material selection in façade and structural design. It highlights the importance of incorporating recycled content, optimizing alloy use based on application, and adopting circular economy strategies such as closed-loop recycling. These findings offer practical guidance for architects, engineers, and policymakers striving toward low-carbon, net-zero building goals.

Abstract: In this study, a hot stamping process, which delivers ready-to-use parts for the production of aircraft components is applied as an alternative manufacturing method to, for instance, machined parts. The research has been focused on examining the formability of an aluminium alloy at high temperatures. An extensive experimental campaign has been conducted to establish the optimal hot stamping process parameters. As a final stage of the development, a demonstrator corresponding to a wing rib with AA2198 aluminium-lithium alloy has been successfully produced. After the corresponding heat treatment, material properties have been restored.

Abstract: Laser beam welding (LBW) is an advanced welding technique based on keyhole welding, which makes use of a laser in order to join metals or thermoplastics. LBW is employed mainly in high volume applications which require high precision using automation, such as the automotive industry. The weldability, welding speed and penetration depth is mostly dependent on the power supplied to the laser, but the material and thickness of the workpiece also influences these parameters. This paper will present how various welding parameters such as power, frequency, the shape and size of the focal point affect different types of aluminium alloys, in an attempt to find the ideal parameters for the 5083 and 6082 aluminium alloys.

Abstract: We present a novel attempt to combine in-situ and ex-situ measurements -- here exemplary for aluminum alloys. For this research we have chosen an Al-1.7Cu-1.3Mg (at.\%) alloy, which has been cast from high purity elements (5N5 Al, 4N Cu and 4N Mg). DSC (differential scanning calorimetry) serves as a basic method, which is employed to determine different precipitation states towards the final S-phase formation: before the formation starts, at the maximum of the exothermal peak, and after the end of the exothermal reaction. By an abrupt truncation of the heating ramp (5 K/min), i.e. cooling quickly to room temperature, the current sample state is frozen-in for a defined temperature. After truncation all samples have been measured without further preparation by X-ray diffraction (XRD), positron annihilation lifetime spectroscopy (PALS). By this treatment we could correlate exactly different sample states, which is impossible by conventional experiments, i.e. heating to a defined temperature and holding for a certain time. This attempt opens new possibilities to investigate defined and comparable sample states by methods, which require extensive sample preparation, like TEM or 3DAP, and in-situ methods like DSC or XRD / EXAFS / SAXS at synchrotron beam lines.

Abstract: Friction stir welding is a non fusion solid state welding technique where sheets are welded with application of frictional heat and pressure together. In this welding process, the tool pin geometry plays a crucial role for development of good quality welded joints. In this work, Al6061 and Al2014 aluminium alloy plates were welded with use of three different tool pin geometries such as straight square, straight hexagonal and taper threaded. Tensile properties and hardness of the welded joints were evaluated. From the results, the welded joints developed with straight square geometry tool tensile properties are better than the welded joint developed with straight hexagonal and taper threaded profiled tools. The better properties are due to pulsating action and higher dynamic volume to static volume ratio of the straight square geometry tool. A microstructural evaluation revealed that formation of more homogeneous distribution throughout the weld nugget for the welded joint made with straight square geometry pin tool.

Abstract: AA7075 is one of the most resistant aluminium alloys, so it is frequently used in very demanding industries as aeronautics or defence. However, the 7075 alloy falls into the non-weldable category thus hardly processable through additive manufacturing processes, and specially on laser-based DED (Directed Energy Deposition). The low absorption together with cracking behaviour remain a challenge for the industrialisation of these processes. Alloying with minor elements or addition of nano-reinforcement have been proven as a successful approach to increase its manufacturability. In this work, the feasibility of printing 7075 with nano-TiC as additive was evaluated. Two compositions with 0.5 and 2% in weight were developed by dry mixing. The powders were characterized by scanning electron microscopy (SEM) and flowability was compared with the unreinforced alloy. With the optimal laser process parameters, 3D coupons were printed to be characterized microstructurally, thermally, and mechanically. Process monitoring using thermal and high-speed cameras was carried out to gain insight into the thermal behaviour of the melt-pool and resulting process stability. After printing, aspect ratio of single tracks was measured, and dilution was also evaluated. Although addition of 0.5% of n-TiC promotes a slight improvement on the alloy, allowing it to be mechanically tested, it still presents some defects as porosity. By increasing the content up to 2%, both the quality and the mechanical performance were enhanced significantly.

Abstract: Additive manufacturing (AM) provides numerous advantages compared to conventional manufacturing methods, such as high design freedom and low material waste. Among the available materials, precipitation-hardenable aluminum alloys are highly attractive for AM due to their high specific strength and low density. Precise control of the processing conditions during AM and post heat treatment (HT) is required to tailor the final mechanical properties. Consequently, many variables, such as the chemical composition and process and HT parameters, must be considered to design suitable alloys for AM. Experimental investigations are, however, limited in variation of these variables. Therefore, computational alloy design approaches allowing for a faster evaluation of many possible variations must be developed. This work presents a high-throughput approach to determine the precipitation kinetics and thermodynamic properties based on the CALculation of PHAse Diagrams (CALPHAD) method. The developed approach is successfully validated for an Al-Mg-Si-Ti-Fe alloy and is applied to screen 243 combinations of chemical compositions and HT parameters. The results confirm the microstructural stability of the Al-Mg-Si-Ti-Fe system to small composition variations.

Abstract: The need to reduce the cost and, therefore, the processing time of metallic materials has pushed academia and industry toward the use of additive manufacturing (AM) technologies. This paper aims to study the effectiveness of a green electropolishing treatment of AlSi10Mg aluminium alloy components produced using Selective Laser Melting (SLM) technology. The influence of treatment duration in relation to specimen surface polishing and the effect on corrosion resistance were evaluated. Morphological characterizations, roughness measurements and electrochemical tests were performed. Specifically, the study identified a set of parameters to achieve a significant reduction in roughness and an increase in the electrochemical characteristics of the components. Green electropolishing could be a viable post-processing treatment substitute to the classical treatment in which environmentally harmful acids are used.

Abstract: Metamaterials, including materials with regularly distributed porous structures, are currently a very intensively developing area of the technology industry. They bring a number of advantages compared to components produced in the classic way. The primary focus of such porous structures is to lighten the product and at the same time preserve its physical or mechanical properties, which subsequently conveys benefits in the form of saving material for the production of the device, and when used in aeroplanes or cars, they also save the amount of fuel consumed, so it can be said that such products and equipment are more user-friendly and environmentally friendly. There are many types of structures with different configurations, different types of basic cells, and different distributions of pores or their topology, so it is very important for the designer to know and decide which type of structure is most advantageous to use in the proposed product that will be subjected to a specific load. The article deals with the investigation of the mechanical properties of porous structures produced by the Direct Laser Metal Sintering (DLMS) method. It is focused on experimentally tested samples made of AlSi10Mg alloy with the Neovius structure, which were produced with four different relative weights. Results of quasi-static pressure testing at a crossbar speed of 10 mm/min (testing machine 250 kN Instron 8802 servo-hydraulic machine) point out that the trend of the influence of the relative weights on the First Peak Local Maximum best described by a second-order polynomial function.

Abstract: In this study, activation energies required for the static recrystallization behavior during the annealing process after cold deformation of Al-Mg-Si alloy to which zirconium was added in various proportions were investigated. Depending on the zirconium content, the activation energies of the alloys were found and compared both experimentally and by calculation. For this purpose, alloys containing 0.1, 0.2 and 0.3 wt-% Zr were cold rolled after taking into solution and quenching. And then, the alloys were annealed at 375 °C and 500 °C for different annealing times. After the alloys were prepared metallographically, their grain structures were examined microscopically. Depending on the temperature, recrystallization-% was found by image analysis and experimental recrystallization-% curves were drawn. The time taken for recrystallization-50% to experimentally find the activation energy required for recrystallization to occur was found from the curves. These values were replaced in the relevant formulations and the required activation energy was experimentally found from the slope of the Arrhenius equation and the ln t_50% and 1/T graph. In order to find the recrystallization-% by calculation, the nucleation rate and growth rate of the new recrystallized grains were found by image analysis. By substituting these values in Johnson-Mehl-Avrami equation, the calculated recrystallization-% curves of the alloys were found. From here, using the relevant equations, Arrhenius equation was passed and the activation energy was calculated from the slope of ln k and 1/T graph. The results showed that the activation energy increased with the increase of the zirconium ratio, and even the most effective zirconium ratio was between 0.1-0.2% by weight in increasing the activation energy. Therefore, this ratio should be considered in processes where recrystallization, which also affects other properties of the alloy, is not desired.