| Abstract Scope |
Aluminum recycling has become increasingly necessary as there is a clear need for sustainable aluminum alloy production. Aluminum and its alloys are highly recyclable, though there are many challenges with separating distinct alloys from one another in the aluminum scrap stream. Depending on the scrap source and type, the aluminum scrap may accumulate several different alloying elements, such as Si, Fe, Mn, Cr, and Cu, which may impact use of that scrap for demanding markets such as aerospace. The “twitch” scrap stream is one which consists of 90-98% aluminum by weight and includes aluminum intensive vehicles and parts which have reached their "end-of-service-life". In this study, in addition to using scrap for conventional markets, conversion of the twitch scrap for additive manufacturing and welding feedstocks is being explored. Compositions within the twitch composition space processed with arc wire directed energy deposition (AW-DED) have been shown to have a similar hardness to 6061-T6, which has a high solidification cracking susceptibility. Current Al weld fillers like 4043 and 5356 are highly weldable but are much softer than 6061, therefore there is an opportunity to discover a composition in the twitch composition space that combines high strength with good weldability. In this presentation, we show predictions of solidification cracking susceptibility of alloys within the twitch composition space. We also discuss results of the SigmaJig weldability test of select twitch compositions. We compare the model predictions against experimental results of the twitch alloy in comparison to commercial alloys 6061, 4043, and 5356. This work shows that alloys combining good weldability and high strength can be identified within the twitch scrap stream which can increase the sustainability of aluminum production. |