HETEROCIRCAL · Intermetallic Phase Heterostructured Circular Aluminium Alloys

A tenet in metallurgy is that the purer metals and alloys are, the better are their properties. However, as recycling in material production increases in importance, so do impurity levels. In aluminium the consequences are particularly harmful because the solubility of most elements in aluminium is very small, resulting in the formation of brittle intermetallic phases. Moreover, once impurities have entered aluminium, it is nearly impossible to remove them. The HETEROCIRCAL project aims to break the paradigm of „harmful“ impurities.HETEROCIRCAL’s main contribution will be to develop a new, ground-breaking class of upcycled materials that can tolerate high levels of impurities. We will achieve this goal by designing intermetallic phase containing heterostructured alloys where previously detrimental intermetallic phases become impurity sinks – sinks which also form a novel heterostructure which features an excellent trade-off between strength and ductility. Here we aim to reverse the common view of primary intermetallic phases in aluminium wrought alloys, and to extend their admitted volume fraction to unexplored regions. Our preliminary work gives evidence that structures with such properties are in fact possible.The main challenge will be to develop viable means of creating beneficial intermetallic phase heterostructures, that are applicable in large-scale. We will address it by manipulating intermetallic phases during solidification and solid-state processing and applying a high-throughput method. HETEROCIRCAL’s aim is also to gain insights into the formation of intermetallic phases at high resolution and their role in the novel heterostructures. The project will meet the enormous challenge of creating sustainable aluminium alloys for a future circular economy, and reduce both the need to dilute alloys with pure aluminium produced from natural resources and the continuous downcycling of alloys. HETEROCIRCAL will also advance European metallurgy in general.