Direct-Hip Aluminium Matrix Composites For Lightweight Structural Rotorcraft Component Performance And Supply Chain Efficiency

Abstract

This paper investigates the performance and manufacturing of aluminium metal matrix composites (MMCs) reinforced with silicon carbide (SiC) for lightweight rotorcraft and aerospace structural components. New data is presented on MMC grade 2009/SiC/15p, produced via powder metallurgy and direct hot isostatic pressing (HIP). Topics evaluated include fatigue behaviour, formability and microstructural characteristics. Results demonstrate that powder metallurgy MMCs offer up to twice the high-cycle fatigue of the highest strength conventional aluminium alloys, with only minor reductions in performance for direct-HIP forms compared to the HIP+forged condition. Advanced characterisation, including synchrotron X-ray tomography, confirmed homogenous microstructure and structural stability under elevated temperature. Compression testing indicated hot formability comparable to conventional 2000-series aluminium alloys, enabling forging, extrusion or rolling where needed. Finally, recent advancements in near net shape (NNS) HIP processing highlight significant opportunities to improve material buy-to-fly ratios and streamline raw material supply chains. These findings position MMCs as a promising solution for weight reduction and performance optimisation in rotorcraft and aerospace applications.