High throughput approach to investigate the effect of varying cooling rates on intermetallic phase formation in high-impurity wrought Al alloys

Breaking the source-sink paradigm in aluminium recycling requires the development of alloys that can tolerate high levels of foreign elements. However, the decreasing solubility of most elements in aluminium with declining temperature leads to the formation of brittle intermetallic phases (IMPs), which can deteriorate the mechanical properties. Understanding how to modify and control these primary phases throughout the processing route is key for the design of novel impurity tolerant wrought aluminium alloys. Various methods of IMP manipulation are reported in literature, with the cooling rate playing a significant role in the size and morphology controlment of the primary IMPs. To investigate the effect of additional IMP modification parameters such as superheating and alloy composition in combination with different cooling rates, a special cooling gradient crucible was designed. This setup allows for a controlled gradient of cooling rates, ranging from rapid to slow cooling, within a single ingot. This ingot can be further subjected to thermomechanical treatments on a laboratory scale, allowing the investigation of a wide parameter field with coupling effects within the sample. High-throughput analysis methods are used to efficiently screen and analyse the data obtained. Results show that this approach not only facilitates a detailed investigation of IMP formation but also allows for an in-depth analysis of the effect of thermomechanical processing on IMP morphology, while reducing the need for large and time-consuming test series.