Achieving sustainable high-performance alloys through master alloy and commodity approaches

The need to achieve ever-better performance in the alloys being developed has led to an excessive increase in the consumption of metals that are now considered critical, resulting in using up the material reserves at an alarming rate. This growth has reached its limit with the emergence of high-entropy alloys and multi-principal element alloys. It is therefore necessary to rethink our sources of raw materials so that we can exploit the possibility of developing alloys- without the direct use of pure metals. This paper reviews two approaches to alloy development, and both approaches enable the development of alloys without relying on high-purity elemental inputs: the master alloy approach and the commodity alloy approach. The development of complex alloys from these two families of alloys is now a real possibility thanks to the powerful design tools at our disposal. These include thermodynamic software and artificial intelligence (AI). The use of a design approach based on master alloys and commodity alloys allows complete exploration of the potential for reusing wastes and scrap metal, promoting more comprehensive recycling, although it still presents relevant long‑term sustainability challenges.