Wire-powder-arc additive manufacturing of alternating graded TiC and B ₄ C particles reinforced aluminum matrix composite structures

Functionally graded materials (FGMs) have attracted significant interest due to their ability to tailor properties throughout the volume. However, achieving cross-scale structural regulation of FGMs, from macro to micro, is difficult using traditional fabrication methods. This study employed a novel arc additive manufacturing process involving wire and powder co-deposition in order to fabricate aluminum matrix composite (AMC) components reinforced by alternating graded TiC and B4C particles along the build direction. The particle-melt coupling behaviour and the FGM microstructure evolution were investigated. A dual-gradient structure of particle content and microstructure was created through precise process control. The variation in mechanical and wear properties across the different layers of the FGM component was analyzed. Meanwhile, the strengthening and wear mechanisms are discussed. Overall, the FGM structure exhibits a gradient of performance characteristics: good plasticity in the lower part, high strength (especially at high temperatures) in the middle part and strong wear resistance in the upper part. Therefore, this FGM structure demonstrates a good balance of strength, ductility and abrasion resistance, and is expected to be used in advanced composite components that require multiple performance integrations.