Architected metal matrix composites from Zr-modified Al7075 and zinc via LPBF and HIP for extrinsic healing applications

This work presents the development and characterization of architected metal matrix composites (MMCs) combining high-strength Zr-modified Al7075 and zinc alloys with the objective of facilitating future extrinsic healing applications. The lattice structures were first designed and produced using Laser Powder Bed Fusion (LPBF), capitalizing on the enhanced printability afforded by zirconium modification. After manufacturing, zinc was infiltrated into the lattices, followed by Hot Isostatic Pressing (HIP). HIP parameters were optimized to enhance densification, promote interfacial bonding, and ensure uniform zinc distribution within the aluminum matrix. Extensive characterization methods were employed to assess the resulting composites, including X-ray computed tomography for internal inspection, scanning electron microscopy (SEM) combined with energy-dispersive spectroscopy (EDS) for microstructural and chemical analysis, and mechanical testing to evaluate performance. Local strain fields were subsequently examined using Digital Volume Correlation (DVC) obtained from in-situ testing. The preliminary findings reveal that zinc has been successfully integrated and consolidated within the lattice frameworks, achieving reduced porosity and improved mechanical properties. Although the evaluation of healing behavior is still ongoing, the chosen architecture and materials lay a solid foundation for future investigations into extrinsic healing mechanisms.