The linear economy follows a “take-make-dispose model, while the circular economy aims for closed-loop system where resources are reused, recycled and regenerated, minimizing waste and environmental impact. Following that, the surge in integration from linear economy to circular economy has been widely witnessed in various European industries for past few years. In automotive industry, aluminium and its alloys are defined as the most suitable candidates, that meets circular economy principles along with technical requirements. However, as per publication by European Commission (EC) on Critical Raw Materials (CRMs), aluminium and its major alloying elements, i.e. silicon and magnesium are declared as CRMs. This poses new constraints to usage of these elements in various automotive structural components. Under these premises, the aim of this work is to implement an innovative roadmap for the development of high-performance aluminium alloys with low content of CRMs and enhanced casting processability. The presented approach shows that by incorporating low criticality concept with high casting processability, it is possible to come up with advanced aluminium alloys with higher mechanical performance that fulfills the requirements of todays manufacturing while addressing global resource challenges. This work also envisioned that researchers in foundry could utilize the descripted approach in designing new aluminium alloys for future applications. Graphic Abstract

The fifth critical raw materials (CRMs) list published by the European Commission (EC) in 2023 poses new restrictions to the usage of lightweight materials in the transportation industry. As per the publication, aluminium (one of the most widely used lightweight metals in the aerospace and automotive industry) has been declared as CRM and an increased criticality trend in its major alloying elements e.g. silicon and magnesium has been observed. Therefore, a novel approach is required to implement the criticality concept in developing new aluminium alloys and their processing for different components in the automotive industry. The present study aims to describe the strategy required to reduce the usage of CRMs in aluminium alloys along with enhanced high-pressure die casting (HPDC) processibility. By integrating criticality and castability assessment, a contribution to the development of sustainable and high-strength aluminium alloys to meet the demands of modern manufacturing while addressing the global resource challenges is presented. This study will also support the implementation of the CRMs concept in materials research and development.

Aluminium thin wall castings are gaining wide acceptance in the automotive industry because of their incomparable design flexibility and higher mechanical properties. For these thin wall castings, fluidity plays a vital role in determining the quality of the final product. The aim of this work is to provide a detailed insight into the development of a multi-channel testing methodology to evaluate the fluidity of aluminium foundry alloys for thin wall applications. AlSi10MnMg foundry alloy has been used to conduct a series of experiments with the aim of designing operative protocols that achieve higher repeatability of the results. The fluidity of the investigated alloy was observed in channels of various cross-sections at three different pouring temperatures, i.e., 680, 710, and 740 °C. The obtained results show that experiments conducted following closely the designed operative protocols, result in achieving higher repeatability. It was also observed that by increasing the pouring temperature, the fluidity and repeatability of the alloy increased greatly. The 3D transient simulations were conducted by means of Altair^® Inspire™ Cast 2021.2 software to study the molten metal behaviour, i.e., solidification temperature and time at the end of each strip for the studied pouring temperatures. The results further reveal that the design methodology, if executed with intrinsic accuracy and precision, will provide a reliable pathway to determine the fluidity of aluminium alloys for various industrial applications.

The aluminum casting industry plays a pivotal role in modern manufacturing, contributing to sectors such as automotive, aerospace, and construction. However, the increasing demand for aluminum, coupled with environmental concerns, necessitates a critical evaluation of its raw material sourcing and energy-intensive casting processes. This study explores the dual challenges of raw material criticalities and furnace selection choices in primary and secondary aluminum casting, aiming to chart a pathway toward more sustainable foundry practices. The study is based on the definition of criticality and environmental assessments for a more circular and climate-resilient future. Raw material criticality assessment is assessed through six factors: (1) abundance of elements in the Earth’s crust, (2) sourcing and geopolitical risk, (3) environmental country risk, (4) supply risk, (5) economic importance, and (6) recycling input, while the environmental assessment is made through two major loads: (i) embodied energy, and (ii) carbon footprints. A comparative analysis of common furnace types, including crucible, induction, reverberatory, and stack furnaces, with varying in-house return rates, is conducted to examine the trade-offs in performance from a sustainability perspective. The findings of the proposed work will emphasize the importance of material and process selection in foundries to save the reserves of critical raw materials, implement better closed-loop recycling systems, integrate renewable energy sources, and develop smart furnace operations to minimize environmental footprints. This comprehensive approach is vital for transitioning the foundry industry toward a more circular and climate-resilient future. Graphical Abstract