Recycling and Sustainability in Cast Shop Technology: Joint Session with REWAS 2022: On-Demand Oral Presentations
Sponsored by: TMS Extraction and Processing Division, TMS: Recycling and Environmental Technologies Committee, TMS: Aluminum Committee
Program Organizers: Mertol Gokelma, Izmir Institute of Technology; Stephen Instone, Speira Gmbh
Monday 8:00 AM
March 14, 2022
Room: Light Metals
Location: On-Demand Room
Process-related Characterization of the Influence of the Die Design on the Microstructure and the Mechanical Properties of Profiles Made from Directly Recycled Hot Extruded EN AW-6060 Aluminum Chips: Alexander Koch1; Sarah Laskowski1; Frank Walther1; 1TU Dortmund University, Chair of Materials Test Engineering (WPT)
In times of climate change, the possibility of producing profiles by direct recycling of aluminum scrap represents a promising alternative to conventional remelting. A new, innovative process chain for direct recycling of aluminum chips consists of a pre-compaction process to consolidate the chips and finally a hot extrusion process to produce the profiles. Particular importance in the process is attached to the removal of oxide layers on the individual chips in order to enable adequate welding. Parameters like pressure and shear strain influence the quality of the interface and can be adapted by the extrusion ratio. Therefore, the defect structure of the profiles, determined by computed tomography, was shown to mainly depend on the extrusion ratio and significantly influence the fatigue life by up to one decade. The findings could be used to establish an extrusion ratio-dependent fracture mechanics-based model for the estimation of the fatigue properties.
Recycling Aluminum Casting Alloy Scrap Using Molten Salt Electrolysis: Xin Lu1; Kyosuke Watanabe1; Osamu Takeda1; Hongmin Zhu1; 1Tohoku University
Currently, approximately 1/3 of aluminum is supplied from aluminum scrap. However, the current aluminum recycling is using downgrading and dilution techniques. The final sink of the recycled aluminum is the aluminum casting alloy products, such as engine blocks and transmission cases used for automobile industry. However, the transition to electric vehicles will drastically reduce the demand for such aluminum casting alloy products. In this study, an upgrade-recycling of aluminum casting alloy containing high content of silicon and copper is achieved using molten salt electrolysis process.
Towards Formulation of AlSi10Mg Alloy from Incinerator Bottom Ash: Astrid Marthinsen1; Joachim Graff1; Martin Syvertsen1; Kjerstin Ellingsen1; Mohammed M'hamdi1; 1SINTEF
In this work, we aim to formulate an AlSi10Mg alloy from aluminium recovered from IBA (IBA-Al) towards potential applications such as Additive Manufacturing and High Pressure Die Casting. To this end we use arc melting as a fast material screening method and controlled melting technique for alloy formulation. We first investigate the effect of arc melting of (un-alloyed) IBA-Al on resulting microstructure and chemical composition using EDS analyses. IBA-Al typically contains oxides which must be handled, as these may promote nucleation of defects such as cracks. We explore the potential of arc melting for partial oxide removal from IBA-Al and compare with IBA-Al treated with salt to remove oxides. Finally, we show initial microstructure analysis of formulated AlSi10Mg from IBA-Al, and the impact of using salt-treated IBA-Al vs. non-salt-treated IBA-Al. This work demonstrates the initial potential as well as challenges with alloy formulation of from IBA-Al.