Improving the ductility of a high-Fe die-casting aluminum alloy via TiB2-induced formation of metastable Fe-rich intermetallics

Vacuum-assisted high-pressure die casting (HPDC) is widely employed in high-end sectors such as base station equipment and new energy vehicles, owing to its exceptional forming precision and outstanding casting performance. Concurrently, with the progress of green manufacturing, recycled aluminum alloys have emerged as a vital option for meeting sustainable development needs, thanks to their high resource utilization and cost-effectiveness. However, accumulation of Ferrum (Fe) in recycled aluminum can lead to the formation of coarse and irregularly shaped Fe-rich intermetallics, leading to the impairment of the mechanical characteristics of the material. This work explores the impact of TiB₂ particles on the mechanical performance of an AlSi10Mg alloy containing up to 0.7 wt% Fe prepared by vacuum-assisted HPDC process. The study confirms that the use of TiB₂ particles improved the ductility of the castings markedly. The modified alloy achieves a tensile strength of 312 ± 10 MPa and an elongation of 9.2 ± 0.3 %. The elongation has recorded an improvement of 50.8 % with respect to the base alloy. The microstructural observation demonstrated that such an improvement can be primarily attributed to transformation of Fe-rich intermetallics from π-AlSiMgFe to β-AlSiFe type, as an unprecedent results of the TiB₂ incorporation.