Cast Shop Technology: Analysis / Special Wagstaff
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Stephen Instone, Speira Gmbh; Mertol Gokelma, Izmir Institute of Technology; Samuel Wagstaff, Oculatus Consulting; Dmitry Eskin, Brunel University
Monday 2:00 PM
February 28, 2022
Location: Anaheim Convention Center
Session Chair: Sam Wagstaff, Oculatus Consulting
2:00 PM Introductory Comments
Microalloying to Inhibit Oxidation of Al-Mg Alloys: Nicholas Smith-Hanssen1; Martin Syvertsen1; Anne Kvithyld1; 1SINTEF
The oxidation of liquid Al-Mg alloys during holding and casting can lead to issues resulting in a poor metal quality and dross formation. Historically, beryllium as a microalloying element has been used to inhibit the oxidation of high Mg alloys. Due to the negative health consequences an alternative is desired for beryllium.Potential alternative microalloying elements to Be were investigated in gram and kg scale TGAs. The effects of Ca, Ce, Ga, Gd, La, Sc and Sr on the oxidation of a 5 % Mg alloy was investigated in a gram scale TGA. Additions of Ce, Ga, Gd, La and Sc were found to have no measurable inhibiting effect on the oxidation with additions up to 1000 ppm. Ca and Sr showed a potential inhibiting effect and were investigated in a kg scale TGA. The results on the effects of Ca and Sr on the oxidation will be presented.
Heat Treatment of Mg-containing Aluminum Alloys 5182 and 6016 in an Oxidizing Atmosphere with 4 % CO2: Cathrine Solem1; Per Erik Vullum2; Gabriella Tranell1; Ragnhild Aune1; 1Norwegian University of Science and Technology; 2SINTEF Industry
Oxidation of aluminum (Al) during production is a widely known problem, and magnesium (Mg) as a typical alloying element increases the oxidation rate with increasing content. It has been established that small additions of CO2 (≥ 4%) in an oxidizing atmosphere have significant inhibiting effect on the oxidation rate of AA5182 (AlMg4.5Mn0.4) and AA6016 (AlSi1.2Mg0.4) discs in the view of oxide layer thickness and mass gain when heat treated at 750░C for 7h. The phases present in each alloy have now been identified and compared with discs heated in synthetic air and argon under the same experimental conditions. The XRD analyses revealed the presence of MgO and MgAl2O4 for all discs, and Mg2C3 for the 5182 alloy when heated in the CO2 gas mixture. The CO2-mixture also resulted in a nanometer-thin amorphous C-layer retarding the evaporation of Mg and inhibiting the oxidation rate for both alloys.
Quality Defects Metallurgical Root Cause Analysis for Aluminium Thin Foil Production: Feyza Denizli1; Yusuf Ízšetin1; Ali Ulus1; Canan İnel1; 1Asas Alumuninum
Aluminium thin foil products are mainly used for food contact materials such as flexible packaging, container and household foils. As the thickness of foil is becoming thinner, the possiblity of occuring some quality problems are increased such as hole, pinhole and scratch. Heterogeneous grain structure, inter-metallic compounds, undesirable impurities transferred from ceramic foam filters and poor liquid metal refining are some of the reasons for these quality problems of the thin foil material produced by twin-roll continuous casting method. In this study, the root cause of the defects such as intermetallic compounds, Al2O3 and SiO2 particles on the aluminium casted coil surface and their effects on final product quality were investigated. Scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) were used for the characterization of the defects both on the casted coil and thin foil materials.
3:20 PM Break
The Origins of Wagstaff Inc. Part 1- Two Emerging Technologies Collide: Frank Wagstaff1; Robert Wagstaff2; Samuel Wagstaff2; 1Retired; 2Oculatus
The journey from machine shop to a position of global leader in Direct Chill (DC) aluminum casting technology began when a distressed father with six mouths to feed purchased a new lathe for the backyard shop housed in the pump house and paid for the lathe by machining components for the lathe manufacturer. Eventually, his two sons, Bill and Frank Wagstaff, would focus their visions in life at the root of two developing technologies: (1) the dawning of computer-controlled machine tools, and (2) the emergence of DC casting for the production of semi-finished aluminum products, i.e., extrusion ingot and large format rolling slab ingot, as the dominant process after WWII. In doing so, they merged their skills in machine tool design and materials research into a business known and recognized across the world as the premier molten aluminum solidification technology.
The Origins of Wagstaff Inc. Part 2- Aggressive R&D: Frank Wagstaff1; Robert Wagstaff2; Samuel Wagstaff2; 1Retired; 2Oculatus
Wagstaff, Inc. grew as the manufacturing capabilities developed into mainstream large-scale computerized numerical control (CNC) machining centers, sometimes even ahead of the commercial machine tool manufacturers. This unique capability positioned the leadership to take on new market opportunities in extrusion ingot, large format rolling slab ingot, and forging ingot as advances in tribology, surface segregation and heat transfer hit the scientific journals in the 1990‘s. The development of new technology based on these scientific advances positioned the company to deliver cutting-edge aluminum solidification technology to the curious but cautious aluminum industry well into the next century. Eventually, the technologies grew and developed into concepts that outpaced the comfort of the owners; thus, they sought a suitable industry partner.
4:25 PM Panel Discussion