Alloys & Billet Process

John D. Lee, Logemann Brothers Company; University of Arizona Department of Engineering Capstone Sponsor, USA 

Logemann, a leading U.S. supplier of scrap processing equipment to the metal fabrication industry for over 140 years, proposes a collaborative study with the University of Arizona engineering capstone program and key aluminum foundry partners to evaluate how scrap aluminum bale density impacts remelt efficiency and sustainability metrics. Bale density will be tested as a controllable input variable during the remelt process. The study will measure its influence on yield, dross generation, carbon emissions, energy consumption, and transportation efficiency. Controlled trials across multiple density levels will support development of a density-yield performance curve and quantify the return on density optimization. By partnering with remelt operators, the project aims to define an industry standard for optimal bale density. The findings will inform best practices for scrap preparation across the secondary aluminum supply chain, with global relevance for extrusion, rolling, and casting operations seeking to reduce costs and carbon footprint. 

Evangelos Giarmas, Anastasia Kotsiaridi, Stavros Arvanitis, Alumil S.A., Production Division; Helen Kamoutsi and Gregory Haidemenopoulos, Department of Mechanical Engineering, University of Thessaly, Greece

This study explores sustainable manufacturing of 6060 aluminum alloy by increasing Copper (Cu) and Zinc (Zn) alloying content, emphasizing recycled aluminum use in casting process. Strategies to boost scrap utilization during remelting include furnace and burner upgrades and impurity removal through sorting lines. The research examines how recycling content affects energy consumption, dross formation, CO₂ emissions, and alloy composition, emphasizing the need to expand tolerance limits for Cu and Zn to improve recyclability. Three alloy compositions were assessed: a primary alloy with minimal Cu (0.01%) and Zn (0.02%), and two scrap-based variants with higher Cu (0.017%, 0.028%) and Zn (0.034%, 0.06%) plus excess Silicon (Si). Mechanical tests, grain size analysis, and corrosion resistance evaluations—including filiform corrosion and acetic salt spray—were conducted. Results show increased Cu and Zn, with excess Si, enhance tensile strength without notably affecting corrosion resistance or anodizing behavior. The findings support sustainable alloy design without compromising performance.

Myrsini Ntemi, Ilias Gialampoukidis, Stefanos Vrochidis, and Ioannis Kompatsiaris, CDXi solutions; Evangelos Giarmas and Anastasia Kotsiaridi, Alumil Group, Greece

Advanced aluminum recycling demands precise insight into scrap melting and dross behavior, yet existing monitoring relies on operator interpretation. We introduce a cost-efficient machine learning framework that transforms a single heat-resistant camera into a source of quantitative furnace intelligence. Real-time semantic segmentation and spatiotemporal inference models estimate scrap volume and surface roughness dynamics to determine delacquering progression with objective accuracy. In parallel, dross coverage and formation rate are continuously quantified to support proactive impurity control and yield stability. The system also identifies operational actions and hazardous heat zones, enabling safer, more consistent interventions. All indicators are integrated into actionable decision support tools that help operators optimize reload timing, avoid excess dross generation, reduce furnace idle periods, and preserve molten aluminum quality. The framework has been validated in a full-scale industrial recycling furnace, demonstrating significant measurable efficiency improvements and emission reductions in real-world production environments.

Eli Harma and Paul Sanders, Michigan Technological University, USA

Alloy 6005A has a recrystallized microstructure due to low dispersoid concentration, which enhances formability but reduces strength. Modifying 6005A alloy to maintain the fibrous microstructure by replacing Mn and Cr with Sc and Zr to produce a finer dispersion of Al3Sc-Zr dispersoids could improve strength without impacting formability. To examine the effect of dispersoid type on hot deformation, four alloys were tested through compression testing and extrusion: baseline 6005A without dispersoid formers, 6005A with Mn and Cr dispersoids, 6005+ with Sc and Zr replacing Mn and Cr and increased Cu, and 6005++ with increased Sc and Zr additions and similar Cu. The 6005++ alloy had the highest flow stress under all conditions, a non-recrystallized extruded microstructure, and texture components of copper, brass, and S. This resulted in the highest mechanical properties, with a yield strength (YS) of 304MPa, ultimate tensile strength (UTS) of 326MPa, and 12.5% ductility.

Veerendra R, Jindal Aluminium Ltd., India

Titanium Boron Aluminum (TiBAl) rod is commonly used during the casting of aluminum alloys to prevent crack formation and refine the grain size. At the incoming inspection stage, it is essential to verify the composition of TiBAl, which typically contains Titanium (5%) and Boron (1%). However, due to the non-availability of Certified Reference Material (CRM) samples with such high concentrations of Ti and B, we are currently unable to conclusively determine the acceptability of the measured compositions. CRM samples with these elevated levels are not readily available in the market. To overcome this limitation, we have developed a method for the in-house preparation of secondary reference samples, which will be subsequently certified through 2–3 independent testing laboratories. This will help to ensure consistent and accurate assessment of TiBAl composition, thereby enhancing the quality of output of the log casting process.

Vipul Sharma, Jindal Aluminium Ltd., India 

During the casting of 7075 aluminum alloy logs, frequent crack formation was observed, resulting in rejection and inconsistent quality. A detailed study was conducted to identify the various possible causes like casting speed, metal temperature, degassing efficiency, water temperature, and homogenizing parameters. Systematic trials were carried out to optimize these process variables. By optimizing the casting speed, metal and water temperatures and modifying the homogenizing cycle, the crack tendency was significantly reduced. The optimized process produced sound billets with uniform structure and improved mechanical consistency. Comparative analysis before and after optimization showed a significant reduction in surface and internal cracks. This study demonstrates how controlled process parameters and metallurgical understanding can effectively resolve 7075 alloy casting issues, improving both yield and product reliability. 

Ali Elashery, Norwegian Univeristy of Science and Technology (NTNU), Norway; X-G. Chen, University of Quebec; and Nick Parson, Rio Tinto, Canada 

Zirconium is widely used as a dispersoid forming addition to Al-Zn-Mg general extrusion alloys such as AA7003 and aerospace alloys such as AA7150. Although some AA6XXX alloy specifications include a Zr addition these are the exception and additions of manganese and chromium are more widely used. This paper examines the dispersoid distributions formed in Al-Mg-Si-Zr compositions with varying; silicon contents subjected to a range of homogenization treatments. Finally, the effects of single and combined additions of Mn and Zr on the extruded microstructure and properties of an AA6082 composition are compared. 
 

Giovanni Battino, Presezzi Extrusion S.p.A., Italy 

This abstract presents an advanced aluminum melting process integrating an automatic scrap charging system with a permanent magnet stirrer controlled by artificial intelligence. The automatic scrap charger enables optimized and continuous feeding of aluminum scrap, minimizing thermal losses, oxidation, and operator dependency. Melt homogenization is achieved through a Presezzi’s patented permanent magnet stirrer whose operating parameters are dynamically adjusted by an AI algorithm embedded in a high-temperature industrial camera installed on the melting furnace. The vision-based system monitors bath surface behavior and scrap dissolution, enabling real-time optimization of stirring intensity and flow patterns. In addition, the process is supported by SPARK (Smart Platform for Assistance Resources and Knowledge), an AI-based assistance tool providing remote troubleshooting and maintenance support through contextual analysis of alarms and operational data. The combined use of automation, AI-driven process control, and intelligent assistance improves thermal uniformity, melting efficiency, process stability, and overall plant reliability. 

Alex Lowery, Wise Chem LLC, USA 

Many companies are blind to the hazards associated with loading and unloading trucks. They only become aware of this hazard when an incident occurs at their workplace. There is a gap in the literature on this hazard that has resulted in many workplaces operating with a hidden hazard on their premises. This paper will explain common pitfalls that result in workers being injured and killed during the unloading and loading of trucks. This paper will provide case studies on how workplaces mitigate this hazard. In addition, this paper will review the proper load securement on flatbed trailers that also injure and kill. Workplaces’ failure to see an obvious hazard in the loading and unloading of trucks as well the proper load securement on trucks will continue to injure and kill workers until our industry places a spotlight on this hazard. 

Jostein Røyset, Eva Mørtsell and Ulf Tundal, Hydro Aluminium Research and Technology Development; Eila Bergene, Department of Physics, Norwegian University of Science and Technology (NTNU); and Trond Furu, Norsk Hydro, Corporate Technology Office, Norway  

Within the Al-Mg-Si alloys there is a tendency to lower ductility with increasing Mg and Si content, for extruded and age-hardened profiles this is particularly evident when the profiles have been air-cooled after extrusion. The reduction in ductility can be countered by small additions of Mn and Cr. It is assumed that the beneficial effect of Mn and Cr is due to the dispersoids formed during homogenization, but it has not been well understood. The present work sums up several studies of base-alloys where the Mn and Cr content has been increased to increase the ductility. The alloys were laboratory cast and extruded, and the extruded profiles were either air-cooled or water quenched. Characterization has been done with mechanical testing, light microscopy, scanning electron microscopy and transmission electron microscopy. It seems that the role of dispersoids is at least twofold; reducing intergranular fracture and influencing the development of the crystallographic texture. 

Jostein Røyset, Martha Indriyati, Eva Mørtsell and Ulf Tundal, Hydro Aluminium Research and Technology Development, Norway 

In the 6005A alloys the added Mn and Cr forms dispersoids during homogenization. When added in sufficient amount one achieves a fibrous grain structure after extrusion, but this also makes the billet much harder to extrude. Therefore, one should seek to add only as much Mn and/or Cr as necessary to achieve the desired microstructure. Also, the effects of Mn and Cr are not identic, and it is not straightforward to determine whether to use Mn, Cr, or a combination of the two. Six alloys with various contents of Mn and/or Cr were studied. Casting and extrusion were on laboratory scale. Two profile types were extruded, one for comparing the maximum extrusion speed before tearing, and one for determining mechanical properties. Profile samples were examined in light microscope and by tensile testing. The results provide a sound basis for optimizing the Mn and Cr contents in these types of alloys. 

Seif Badawy, Yahya Mahmoodkhani and Steve Coates, Signature Aluminum Canada Ltd., Canada 

Inverse segregation is the accumulation of alloying elements in the skin of direct chill–cast aluminum billets at concentrations higher than in the bulk, driven by convection, feeding flow, and shrinkage-induced movement during solidification. This study examines the relationship between inverse segregation severity and billet skin thickness, with emphasis on alloy chemistry, casting speed, and cooling practice. Increased inverse segregation is shown to produce thicker, more highly alloyed surface layers that increase scrap rate during extrusion. Through experimental trials and simulation, the study correlates skin thickness to extrusion recovery, demonstrating that it directly reduces recovery and increases cost per unit length extruded. Even small reductions in inverse segregation can significantly decrease skin thickness, improving yield without compromising press performance. The results highlight DC casting control as a critical upstream lever for improving extrusion recovery, reinforcing the importance of integrated casting–extrusion process optimization for modern aluminum extrusion operations. 

Emrah Ozodogru, Isik Kaya, Aybars Guven, Aleyna Gumussoy and Hilal Colak, Tri Metalurji, Turkey 

The 6063-aluminum billet alloy has been widely used in production of profiles. Homogenization is an essential process for having a good extrudability and high-quality end product. Homogenization process gives a homogeneous microstructure by reducing micro segregation and well-designed intermetallic phases. However, If the iron level is so high, especially in the high recycle content aluminum billet, the AlFeSi phase formation and their behaves during homogenization is different than the primary aluminum billet due to the complex AlFeSi formation. Making an identification of AlFeSi based phases is one of the most important stages for understanding the phase transformation in homogenization process. In this study, microstructural assessment has been applied to the AlFeSi phases for setting the homogenizing cycle and pointing out the importance of the high recycled content aluminum billet production. 

Tanju Çeliker, Harun Uslu, İlhan Karabiyik and İrfan Eker, ONAT Aluminyum SAN. TİC. A.S., Turkey 

This study investigates the influence of secondary aluminum content on the chemical composition, inclusion characteristics, microstructure, mechanical properties, and process stability of EN AW 6082 alloy for automotive extrusion. Billets containing varying proportions of secondary aluminum were produced under controlled casting conditions. Particular attention was given to Mg–Si–Mn balance, impurity accumulation, especially Fe, and the formation of Fe-rich intermetallic phases together with non-metallic inclusions originating from recycled input. Increasing secondary content intensified impurity sensitivity and inclusion-related heterogeneity, promoting β-AlFeSi phase formation when critical Fe levels were exceeded and reducing ductility. However, optimized compositional control and melt treatment practices mitigated inclusion defects and preserved target mechanical properties within industrially acceptable limits. The results demonstrate that high secondary aluminum utilization in 6082 alloy is feasible when elemental impurities and melt cleanliness are carefully controlled, supporting low-carbon and circular aluminum production without compromising structural performance. 

Jostein Røyset, Eva Mørtsell and Ulf Tundal, Hydro Aluminium Research and Technology Development; Hedda Øye and Randi Holmestad, Norwegian University of Science and Technology (NTNU); Sigurd Wenner and Calin Marioara, SINTEF Materials and Nanotechnology, Norway; and Helen Weykamp, Hydro Aluminium Metals, USA   

The effects of Ti and V additions to a 6005-aluminum alloy were investigated with respect to corrosion susceptibility and cooling rate from extrusion. Both Ti- and V-containing alloys exhibited a significant improvement in intergranular corrosion resistance. The depth of intergranular corrosion was substantially reduced by the addition of either element, with Ti showing the strongest effect. Crush-, bend-, and tensile testing demonstrated that the Ti- and V-modified alloys performed comparably. The beneficial effect was most pronounced at slow cooling rates, where both Ti and V increased the bend angle significantly. Peritectic elements such as Ti and V segregate to the centers of dendrite arms during solidification, leading to Ti/V banding during extrusion. These bands were confirmed by optical- and electron microscopy in addition to energy-dispersive X-ray spectroscopy. The hardening precipitates formed during artificial aging were quantified and characterized by transmission electron microscopy and were unaffected by Ti or V additions. 

Endre Hennum, Jon Møretrø and Ulf Tundal, Hydro Aluminium AS, Norway 

This work compares recrystallized and non‑recrystallized Al‑Mg‑Si extrusions for crash applications. Two alloys with identical yield strength but different grain structures were subjected to bending and quasi‑static axial and lateral compression tests after quenching at different rates after solution heat treatment. The recrystallized alloy shows excellent bendability transverse to the extrusion direction at high quench rates but suffers from strong anisotropy and reduced ductility as quench rate decreases, which limits performance in lateral compression. The non‑recrystallized alloy displays lower anisotropy and better bendability along the extrusion direction. Although it loses yield strength more rapidly with slower quenching, it retains ductility more effectively, giving improved performance—particularly in lateral compression. Overall, the results indicate that non‑recrystallized alloys may be advantageous for certain lateral side‑crush applications. 

David Roth, GPS Global Solutions, USA 

Dross processing has moved forward significantly since the 1960s when it was common to take materials directly to the land fill. The industry has shifted from preserved aluminum being in the 20% range to current processing systems preserving and recovering maximum amounts of aluminum in the 60 - 70% range. Also, for the first time there are multiple processes that recover aluminum and produce by products for sale and eliminate land filling of a salt cake material. This paper will detail the historical development and today’s current implementation of all of the commercial dross processing systems used in the aluminum industry. 

Alex Poznak, Martha Indriyati and Ole Runar Myhr, Hydro Aluminium Research and Technology Development; and Trond Furu, Norsk Hydro, Corporate Technology Office, Norway 

Extruded profiles that retain a fibrous, unrecrystallized grain structure can offer significant performance benefits for structural applications, including higher strength and improved damage tolerance. The tendency for an alloy to recrystallize is strongly dependent on the dispersoid density (controlled by Mn, Cr content and homogenization practice), as well as the extrusion process (e.g. temperature, speed, and reduction ratio). Alloys with insufficient recrystallization resistance become sensitive to extrusion process variation, which can cause grain structure to become the limiting factor in extrusion speed. Increased recrystallization resistance, however, typically comes at the cost of reduced extrudability due to increased flow stress and deformation heating. The present work examines this balance through extrusion trials coupled with through-process microstructure modelling. The results highlight how alloy and homogenization can be strategically matched to an extrusion process to optimize extrudability while stabilizing a fibrous grain structure. 

Alyaa Bakr and X. Grant Chen, University of Quebec; and Paul Rometsch, Rio Tinto Aluminium, Canada 

Scandium is a highly effective microalloying element for aluminum, offering precipitation strengthening, improved recrystallization resistance and enhanced microstructural stability. However, its broader industrial use is limited by cost constraints, making it important to maximize benefits from minimal Sc additions. This study investigates the extrusion behavior, microstructural evolution and mechanical and corrosion properties of 1xxx and 3xxx alloys containing ≤0.2 Sc and 0.1 Zr (wt.%). The 1xxx alloys with Sc exhibited extrusion pressures close to those of the 3xxx base alloy but with higher strengthening potential (approaching the strengths of soft 6xxx alloys). Unlike the fully recrystallized base alloys, the Sc-containing variants developed fibrous grain structures, demonstrating enhanced recrystallization resistance. Furthermore, multi-micro port extruded tubes were subjected to simulated brazing and post-braze aging, after which the Sc-containing 1xxx alloys showed yield strengths up to 190% higher than the 3xxx base alloy, highlighting their potential for high-performance niche heat exchanger applications. 

Nicholas Shaber, Wagstaff Inc., USA 

Optimized casting processes and technologies significantly enhance throughput and operational efficiency in the cast house. Optimization extends beyond the casting pit, to downstream processes such as material scalping in large forge stock that is a direct scrap cost impacting profitability. By optimizing individual alloys within a specific mold technology, maximum throughput can be achieved irrespective of the alloy being cast. Improved casting conditions minimize surface shell segregation, which in turn reduces the need for surface scalping to reach final product dimensions, saving millions of pounds of scrap annually. Increasing the packing density of molds within the existing table footprint allows for a higher yield of pounds per drop, leveraging increased furnace capacities. The reduction of center distances between positions mitigates heat loss and temperature gradients across the table, resulting in less wasted thermal energy and more stable, consistent starts for large strand count systems, a common challenge in such setups. 

Sumit Gahlyan, Madhuker Kishan, Pankaj Wanjari, P Mohanraj, and Deepu Sankar, Hindalco Industries Limited, India 

AA6xxx alloys form a major share of extrusion products, where press solutionizing is controlled by maintaining the extrudate exit temperature above the alloy’s solvus. Accurate control of exit temperature is therefore critical, however shop‑floor practice typically relies on literature solvus data, experience, and CALPHAD predictions. Although equilibrium solvus is a natural choice, kinetics of dissolution is usually not considered when deciding the exit temperature. During homogenization, Mg‑Si precipitates develop a broad size distribution dependent on cooling rates, and dissolution time depends on particle size. Hence, the effective solutionizing temperature during extrusion may deviate from the equilibrium solvus. This study replicates typical plant thermal cycle under controlled laboratory conditions—from homogenization through simulated press exit—to quantify the difference between desired exit temperature and equilibrium solvus. Electrical conductivity and hardness were used to estimate dissolution, the findings were validated through DSC, Thermo‑Calc, TEM analysis, and gage  studies confirming methodological robustness. 

Alex Poznak, Hydro Aluminium Research and Technology Development; Tracy Berman, Qianying Shi, Tim Woike, and John Allison, University of Michigan; and Edward Cole, Hydro Extrusions USA LLC, USA 

Due to the challenges of 7xxx extrusion, there is growing interest among extruders and OEMs in high strength 6xxx alternatives. Alloys like AA 6110 are capable of achieving high strengths of around 400MPa yield but are more sensitive to process and equipment variations compared to conventional 6xxx. A key challenge to maximizing strength is the lack of complete dissolution of strengthening elements at the exit of the die. This work evaluates the impact of different homogenization cooling and billet pre-heat strategies through laboratory-scale simulations on an AA 6110 alloy. The resulting effects on Mg, Si, & Cu containing particle distribution and dissolvability are quantified. This provides guidance for process development to better achieve consistent high strengths in AA 6110.  

Takeshi Saito and Scott Rogers, Hydro Aluminium Asia, Singapore; and Malgorzata Halseid, Hydro Aluminium Metal, Norway 

The Japanese Industrial Standards (JIS) H 8602, commonly used in Japan and some countries in Asia, defines thin anodic oxide layers and transparent organic coatings for anodized surface on aluminum and its alloys. The defined surface and its process are different from the ones used in the US, Europe or other regions. Interestingly, it is potentially less susceptible to surface defects as preferential grain etching (PGE) and corrosion, implying lower sensitivity to trace elements as Cu, Zn and Fe. In this study, we will present an investigation of anodized surface under JIS H8602 in 6063 alloy with different concentrations of Cu, Zn and Fe. We will also highlight differences between the JIS standard and standards in Europe/US and discuss the potential 6063 recycled specifications compatible with the JIS anodizing. 

Annica Crispin, Ronnie Pettersson, and Alexis Skubich, Hydro Extruded Solutions AB, I&T, Sweden 

EN AW‑6060 is the standard extrusion alloy due to its extrudability and excellent surface finish. However, its mechanical strength often exceeds functional design requirements, leading to over‑specification that increases cost and reduces aluminum’s competitiveness versus alternative materials. This work presents a sustainable Al–Mg–Si extrusion alloy designed as an alternative to EN AW‑6060, offering lower CO₂ footprint, reduced weight, and improved processability. The concept is based on a lean, precipitation‑efficient Mg–Si system with higher tolerance to residual elements such as Cu and Zn, commonly present in recycled aluminum. The lower alloying level also improves surface appearance, even with elevated Cu and Zn contents. Through optimized alloy design, extrusion parameters, pre‑deformation, and aging strategies, mechanical properties can be tailored from lower application‑specific levels up to standard 6060 performance. The alloy surpasses 6060 in extrudability, surface quality, and corrosion resistance, with yield strength tunable between 120MPa–190MPa and up to 30% higher extrudability. 

Nicholas Shaber and Jacob Kerbs, Wagstaff Inc., USA 

Hands-free billet casting has become a reality, utilizing automated gas control and bleed-out detection systems, significantly improving safety and efficiency. New and enhanced automated gas control systems in AirSlip casting regulate gas flow to the molds at greater maximum pressures to ensure consistency to prevent bubbling or out-of-process conditions. These systems include automated gas control valves that maintain optimal gas flow rates for each mold, thereby reducing the need for manual adjustments that lead to inconsistencies. Optimization of casting gas parameters eliminates manual operator intervention during start-up, a crucial step for maintaining safety and process control. Integrated bleed-out detection systems are critical for enhancing safety by identifying molten metal containment loss in seconds, preventing catastrophic incidents and minimizing safety risks to personnel. The integration of these technologies allows for remote operation and access to critical information and control from a safe distance, thereby improving overall casthouse safety and operational reliability. 

Devesh Chouhan, Brian Milligan, Nicole Overman, Tanvi Ajantiwalay, Matthew Olszta, Jens Darsell, Timothy Roosendaal, Alan Schemer-Kohrn, and Scott Whalen, Pacific Northwest National Laboratory, USA 

Floated fragmentizer aluminum scrap (Twitch) sorted primarily from shredded automobiles (Zorba) is a vast resource that has not found utility in the extrusion industry. Due to high levels of silicon, iron, and copper, the use of Twitch is presently restricted to non-structural casting applications with no route to wrought alloys existing in the secondary recycling industry. New technologies that enable utilization of Twitch as a substantial constituent in wrought products, namely extrusions, would be a significant advancement in the field. This work highlights recent success where Shear Assisted Processing and Extrusion (ShAPE) has been used to fabricate seamless tubing from cast feedstock blended from 99% post-consumer Twitch, 6XXX Re-Melt Scrap Ingot (RSI), and Used Beverage Cans (UBC). Microstructural and mechanical characterization will be presented showing improved yield strength, ductility, and corrosion resistance compared to AA 6082-T6, one of the highest performing extrusion alloys used in the US automotive industry. 

David Mann and Borja Lopez, Innerspec Technologies, USA 

This paper presents the latest evolution of the CHORUS AL-NB system, now implemented as a robotic platform for automated inspection of round aluminum cast ingots. Designed for inspection of extrusion ingots, the system uses non-contact EMAT (Electro-Magnetic Acoustic Transducer) technology to perform rapid, couplant-free normal beam ultrasonic inspection with real-time defect detection and full data traceability. In this configuration, dual EMAT sensors are mounted on an industrial robot and coordinated with laser tracking to ensure precise log positioning and repeatable centerline interrogation. The robotic architecture enables adaptive positioning across varying billet diameters while maintaining optimal sensor alignment. Centerline cracks and internal discontinuities associated with direct-chill casting are detected in real time, with automated marking and quarantine capabilities. The robotic implementation enhances flexibility, durability, and inspection consistency within modern aluminum casting and extrusion facilities. 

Bartlomiej Plonka, Boguslaw Augustyn, Dawid Kapinos, Piotr Korczak and Konrad Zylka, Lukasiewicz Research Network – Institute of Non-Ferrous Metals; and Piotr Benisz, Extral Sp. Z o. o., Poland 

The aim was to produce and test of billets from 6xxx series Al alloys, with a specified scrap content and grade (post-production and post-amortization scrap), and extrude them into profiles. The studies were conducted on AW-6082 and AW-6005 alloys, with scrap content of 70%-95%. Tests were carried out on the casting process of 4-inch-diameter billets in terms of the type and proportion of scrap used and the extrusion process on a semi-industrial scale by a 5MN press. The quality of the liquid metal was assessed including the Prefil Footprinter. Extruded profiles had a correct, defect-free surface and structure. The mechanical properties of the extruded and heat-treated profiles to T5 temper indicate that all variants achieved the minimum requirements for the tested alloys. Variants with a lower scrap content up to 70% achieved slightly higher mechanical properties than those with a higher scrap content of around 80%–95%. 

Sumit Gahlyan and Manu Saxena, Hindalco Industries, Limited, India 

AA2xxx alloys are amongst the earliest commercial heat‑treatable aluminum systems, known for their excellent strength and workability. The strength is achieved through precipitation of Al‑Cu, Al‑Cu‑Mg, and Mg‑Si phases, dependent on alloy chemistry. During homogenization, these alloys also generate nano‑sized Mn‑based dispersoids that inhibit recrystallization and suppress abnormal grain growth (AGG). However, the combined influence of dispersoid size distribution on ageing precipitation behavior and resulting mechanical properties remains insufficiently understood. In this study, two homogenization treatments were applied to a single AA2xxx alloy to evaluate how variations in dispersoid populations affect AGG and aging response. Additionally, the role of identical homogenization cycles on two grades with varied Cu and Si on mechanical properties and AGG is examined. The industrial‑scale experiments, supported by SEM and TEM characterization, provide key insights into thermal‑cycle‑driven interactions between dispersoids and strengthening precipitates, highlighting their collective impact on microstructure stability and final mechanical performance. 

Nicholas Tebbe, Wagstaff Inc., USA 

Metal temperature management is a key challenge for aluminum casting. Molten metal loses significant heat during transit from the furnace to the casting machine. This causes three problems: 1) the initial metal is cold at the start of a cast; 2) the temperature fluctuates from the beginning to the end of a cast; and 3) the temperature fluctuates from one cast to another cast. Internally heated refractory technology addresses these three problems. It is designed to control temperature of the molten metal during transit. This presentation will explain how the system works, what the technology has achieved, why internal heat is uniquely advantageous, and what benefits it offers to the operation. 

Manu Saxena and Sumit Gahlyan, Hindalco Industries Limited, India 

Automotive and critical industrial applications are driving extrusion plants toward automated ultrasonic testing of aluminum logs. This paper presents the industrial implementation and qualification of an online phased array ultrasonic testing (PAUT) system developed to meet ASTM International B594 Class B acceptance requirements. While phased array ultrasonic testing (PAUT) is a practical route for production inspection, transitioning from conventional manual ultrasonic testing (MUT) to online phased array ultrasonic testing (PAUT) involves significant industrial and technical challenges in achieving reliable volumetric coverage and stable signal response. This study demonstrates verification of volumetric (Diameter x Length) interrogation through radial/axial overlap, multi‑diameter qualification, sensitivity control in sectional depth, and repeatability trials under production conditions. Key learnings related to calibration discipline, coupling stability, and production‑scale reliability are presented. The work provides a structured framework for extrusion plants adopting PAUT to achieve standards‑compliant volumetric inspection of aluminum logs. 

Nicholas Nanninga and Alex Fryman, Secat, Inc., USA 

Advanced aluminum alloys are increasingly being used in automotive, aerospace, and structural applications to provide weight reduction and increased fuel efficiency. AA6XXX-series alloys are particularly desirable for the combination of mechanical properties, workability, and corrosion resistance they exhibit. Unfortunately, efforts to promote higher strength in these alloys are often limited by either the solubility limits of Mg and Si or the propensity for intergranular corrosion with additions of Cu. This paper focuses on the development of Cu bearing AA6XXX alloys with Ni additions. Initial work showed improvements in corrosion resistance with Ni concentrations of around 0.3 wt.% in flat rolled samples of an AA6110-like alloy. More resent research explored the influence of Ni (0.30 wt.%) and Cu (0.45 wt.%) on an extrusion grade AA6061 alloy. For these alloys, the corrosion response was slightly worse in the alloy containing elevated Ni and Cu, however the tensile properties were significantly enhanced. 

Aybars Guven, Emrah Ozdogru and Isik Kaya, TRI Metalurji, Turkey 

As the aluminum industry moves toward REACH-compliant materials, lead-free alloys are becoming very important. This study focuses on the Direct Chill (DC) casting and microstructural characterization of the lead-free 2033 alloy. This alloy is a sustainable alternative for high-speed machining applications. Our work investigates the relationship between casting parameters and the distribution of secondary phases. We present a detailed analysis of the as-cast microstructure, focusing on the Al-Cu-Mg intermetallics, distribution of eco-friendly chip-breaking phases and grain refinement. Additionally, we studied the effect of the homogenization process on microstructural uniformity. The dissolution and distribution of the microstructure were evaluated to ensure good extrusion quality and mechanical properties. By combining industrial production with metallurgical analysis, this study shows our progress in producing lead-free solutions. These results provide a practical framework for the production of 2033 alloy grades that meet global sustainability standards while maintaining high machinability. 

Bala Jayachandran and Jeff Victor, Hydro Extrusion USA LLC, USA 

The automotive industry is steadily increasing post-consumer scrap (PCS) use in aluminum alloys to reduce carbon footprint and support circularity. However, higher PCS content in automotive extrusions creates challenges in chemistry control, mechanical property consistency, surface quality, and extrudability. This paper reviews PCS use in automotive extrusion alloys, focusing on how scrap-derived residual elements especially Fe, Cu, and Zn accumulate and influence aging response, tensile strength, ductility, and property variability in common 6xxx-series and emerging high-strength extrusion alloys. Manufacturing risks relevant to customer requirements, including surface defects, weld integrity, and quench sensitivity, are also assessed. Mitigation strategies reported in literature and industry practice are summarized, including dilution with primary metal, melt treatment/filtration, and targeted process-control adjustments. The paper provides a practical, manufacturing-focused framework for increasing PCS utilization while maintaining performance and quality expectations for automotive extruded products. 

Simon Lille, ABB Metallurgy, Sweden 

Understanding how stirrer placement influences molten aluminum behavior is increasingly important as recyclers process lower‑grade, contaminated scrap. Two‑chamber furnaces help reduce oxidation losses by separating the hot melting zone from the colder charging zone, yet natural convection between these chambers is limited. This makes forced circulation essential for improving heat transfer, stabilizing mixing and supporting efficient melting. This paper presents a numerical study of electromagnetic stirring (EMS) in three installation positions within a typical two‑chamber furnace. The analysis compares resulting volume flow rates, circulation patterns and mixing dynamics. The findings highlight how stirrer positioning affects heat transfer, mixing time and overall flow structure, offering guidance for furnace designers and aluminum producers seeking higher productivity and more consistent melt quality. 

Jorge Fernandez, RiA Cast House Engineering LLC, USA 

Efficient scrap charging has developed over the past 20 years, from mechanized units that replaced simple charge chutes and operator driven fork trucks, to heavy duty autonomous operated machines driven by intelligent computers and vision systems. These systems have replaced operators in the most dangerous aspect of the cast house, charging scrap in front of an open furnace. Autonomous skimming can now replace fork truck skimming, eliminating refractory damage, shortening skim cycles and cleaning the furnace much better by removing all the dross automatically. This paper will cover the use of these types of systems. 

Johnny Pangborn, Metalstar Consulting LLC; and JD Schloz, Schloz Technologies, USA 

One of the most important--yet neglected--relationships in the aluminum extrusion industry is between billet supplier and extruder; specifically, the non-commercial, or "technical" relationship. Historically and contemporaneously, there are substantial disconnects between billet production and extrusion, with neither appreciating the others' constraints--financial, logistical, or technical. While these problems may be lessened by vertical integration, they still exist within companies that "silo" information or do not have adequate technical overlap. For open-market billet, it is frustrating to extrusion engineers who cannot directly converse with counterparts in the casthouse and know little about technical difficulties that exist. Similarly, casthouse engineers hear only basic explanations of extrusion problems, severely limiting their ability to solve problems for their customers. This paper will highlight the key technical, logistical, and financial impacts of the billet-extrusion knowledge divide; it also seeks to provide a roadmap to resolving issues through transmission of useful information and general understanding between counterparts. 

Arif Hussain, Gulf Extrusions LLC, United Arab Emirates 

The growing demand for lightweight and crashworthy automotive structures has intensified the need for aluminum alloys that combine high strength, controlled ductility, and stable energy absorption under dynamic loading. This study presents an integrated alloy and process design strategy. The approach optimizes chemistry, homogenization, extrusion parameters, and heat treatment superior crash performance. A modified composition was developed with controlled alloying additions to refined precipitate distribution and controlled Fe-rich phases. Billets were produced under optimized casting conditions, followed by homogenization. Extrusion trials were conducted at varying temperatures and ram speeds. Subsequent solution treatment and artificial aging were tailored. Tensile testing, hardness evaluation, and quasi-static crush testing to assess Average Crush Force (ACF). Micro structural analysis correlated precipitate morphology, grain size, and texture evolution with crash performance. The integrated design approach shows that precise control of alloy and processing improves energy absorption and crush stability over conventional 6xxx alloys. 
 

Arif Hussain, Gulf Extrusions LLC, United Arab Emirates 

The extrudability of 6xxx aluminum alloys is strongly influenced by alloy chemistry and processing parameters that govern flow behavior, microstructure evolution, and surface quality during extrusion. This study examines the combined effects of Mg/Si ratio, Fe content, and microalloying additions alongside billet casting conditions, homogenization practice, and extrusion temperature and ram speed. Controlled variations in composition were designed to regulate precipitate formation, dispersoid density, and the morphology of Fe-rich intermetallic phases. Optimized casting and homogenization reduced segregation and improved billet uniformity, enhancing hot workability. Extrusion trials evaluated press load, metal flow stability, surface integrity, and die performance under different processing windows. Microstructural characterization correlated grain structure and precipitate distribution with extrusion response. Results demonstrate that balanced Mg/Si ratios, minimized detrimental intermetallics, and optimized thermal–mechanical parameters significantly improve extrudability, enabling higher productivity, reduced defect formation, and improved dimensional consistency in 6xxx aluminum profiles.  
 

Robert Matuska, Shape Corp., USA 

Black billets have been a source of curiosity, complaints and the scapegoat of many issues in the extrusion process. Despite this, the cause of this condition and the ramifications it has on the extrusion process is generally not well understood. This work will provide a metallurgical explanation of how black billets form and review some of the challenges they represent in the extrusion process. This paper will thus provide a basis for preventing black billets while also discussing some of the ramifications of this condition on the extrusion process so the impact can be minimized. 

Robert Matuska, Shape Corp., USA 

The aerospace industry has been a driving force of alloy development for most of the aluminum industry’s existence. Many of the original alloys, developed nearly a century ago, are still in use today but new alloys and manufacturing capabilities have significantly changed how airframes are currently made. This work will review the history of these alloy developments and the technical challenges they addressed. Alloy and process solutions relative to fracture toughness, fatigue, tensile strength and stress corrosion resistance will be discussed and explored. Finally, the impact these developments have had on the aerospace extrusion industry will also be discussed and reviewed. 

Muhammad Sajjad, Eystein Vada and Helen Weykamp, Hydro Aluminium Metal, Norway; Mike Heemstra and Brian Losey, UACJ Automotive Whitehall Industries Inc.; Madi Kehoe, Veronica North, David Abraham, and Ken Gryc, Michigan Technological University, USA 

Automobile manufacturers are under increased pressure to minimize time from vehicle design to production. A significant part of this timeline is dependent on how quickly extruders can progress from alloy trials to bid submission. Extrusion simulations can reduce the number of required trials and thereby accelerate this process. However, commercial simulation software typically relies on material models for generic alloys, which are often not representative of alloys specialized for extrudability, strength or crash performance. In this work, two automotive grade 6xxx aluminum alloys were characterized at four different temperatures (450°C, 490°C, 520°C, 570°C) and three different strain rates (0.1, 1, 10 s⁻¹). Based on the flow stress data several constitutive material models were calibrated. The simulation study is conducted to assess the accuracy of the models by comparing the data from the production die. Overall, results showed improved accuracy with the modified models which could significantly reduce development time. 

Isik Kaya, Emrah Ozdogru, Aybars Guven, Aleyna Gumussoy, TRI Metalurji, Turkey 

Homogenization is a critical heat treatment for high-strength 7xxx-series (Al-Zn-Mg-Cu) aluminum alloys. While the initial soaking stage is important, the subsequent cooling process also plays a decisive role in determining the final state of the material. The cooling rate affects residual stress, solute distribution, and secondary phase precipitation. These factors regulate the downstream formability of the billets. Inappropriate cooling paths can lead to the formation of coarse phases, such as η(MgZn₂) and S(Al₂CuMg), which significantly alter the alloy's flow stress and response to subsequent heat treatment. In this study, single-step and double-step cooling conditions were simulated and controlled using in-situ differential scanning calorimetry (DSC). Following DSC analysis, the same samples were used for microstructural characterization. This methodology provides a direct correlation between thermal transitions and phase evolution. The findings emphasize the importance of optimizing cooling to ensure process stability and consistent material performance in industrial applications. 

Eskild Hoff, Hydro Aluminum Metals USA LLC, USA 

A comparative extrusion trial was conducted on an indirect extrusion press using aluminum extrusion billets produced by conventional Direct Chill (DC) casting and Low-Pressure Casting (LPC) technology, evaluated in both scalped and unscalped conditions for a 6xxx series alloy. Extrusion speed capability and extruded material quality were assessed. Paper shows details in difference between conventional DC-cast billets in scalped condition as compared to LPC billets in unscalped condition, including maximum extrusion speed comparison and surface quality assessment. Also compared were DC cast billets in unscalped condition and LPC billets in scalped condition. The results indicate that LPC technology expands the processing window for indirect extrusion while reducing reliance on billet scalping operations. 

Md Hanif Hamzah, Press Metal Aluminium Holdings, Malaysia 

The current sustainability drive towards meeting the standards has driven the remelt process into various challenges. The availability of the scraps has caused the industry shortage of metal to remelt. This has caused the prices of aluminum scrap to be much higher and the cost to make such a billet is far more expensive than buying a normal recycled aluminum billet. It also looks into the percentage of scrap used for the process and its effect is examined on the extruded products. The effect on anodizing is examined and compares the product using a primary billet. The changes in the color tone with the increase in the composition affects the anodizing quality. Thus, it is important that the new drive in sustainability needs a new standard of acceptance in the quality of the extruded product without affecting the mechanical properties. 

Md Hanif Hamzah, Press Metal Aluminium Holdings, Malaysia 

An overview in the billet casting practices is examined with the improved equipment in the casting process. The billet defects examined the surface finish of the billets such as the cold folding and white stains encountered in the process of making the billets. The defects examined the root cause and laboratory results to do the corrective actions. White stains are examined after the homogenization process and examined the stains through metallurgy process. Pin hole defects, which are created from the degassing process are also examined and analyzed. The data from the degassing practices are examined and corrective actions taken to ensure a smooth quality is achieved. Other defects such as the bleeding during casting are also analyzed to find the solutions.