New Generation of Castable Al Alloys Possessing High Strength and Elevated Electrical Conductivity

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The demand for high strength castable Al-based alloys possessing high conductivity is continuously increasing. One of the main applications of these Al alloys is on fabrication of electric vehicle (EV) components. These components are usually made through high pressure die-casting (HPDC) process, which requires high hot tearing resistance. Hence, in addition to high yield strength and improved electrical conductivity (EC), good castability is also required. However, developing such a new Al alloy is quite challenging, as the abovementioned requirements are contradicting factors. Therefore, a comprehensive and systematic research plan is required to develop high strength Al-based alloys exhibiting high EC with sufficient castability. Three principal short term objectives of the current research program are to: 1) Develop castable Al conductors strengthened by nanosized precipitates/dispersoids using a systematic integration of thermodynamic models and experimental data; 2) Investigate the influence of heat-treatment parameters on the formation of nanosized precipitates/dispersoids; 3) Develop high-strength castable aluminum matrix composites conductors reinforced by Al2O3 nanoparticles (nanop) and conduct pilot HPDC-manufacturing trials. Al-Ni-based alloys containing various Si, Mg, Fe, Ce and Zr contents will be considered. Thermodynamic modeling will be employed to simulate the impact of the alloying elements on solidification path, microstructure evolution, and hot tearing susceptibility. The castability, mechanical properties and EC of the promising alloys will be investigated by experimental trials. An innovative heat treatment process will be developed to promote the nanostructured precipitates/dispersoids. Advanced microstructure characterisation will be conducted to study the formation kinetics of the precipitates/dispersoids. A property model will be developed to identify the contribution of underlying strengthening factors on strength and EC. Furthermore, Al matrix composites conductors reinforced by Al2O3 nanoparticles (nanop) will also be explored. The Al melt will be synthesized by NiO particles, to promote Al2O3 nanop in Al matrix through an aluminothermy reaction. A pilot manufacturing HPDC trials will also be conducted to validate the developed products' processability and performance. The long-term objective of this ND program, aligned with the Al industry's priorities, is to establish an inclusive and diverse research group capable of answering the practical and fundamental challenges related to Al transformation. Over the next 5 years, achievement of these long-term research goals will provide the foundation for future projects. This program will also provide multidisciplinary training for 5 HQPs who will be competitive in the job market. The program will also encourage many fruitful national and international collaborations, and contribute to the evolution of science-based improvements in Al products and process development.