Graded SiC reinforced magnesium wires: Towards high throughput composite alloy discovery

Abstract

High-throughput methods can accelerate the development of metal alloys and (nano)composites, both empirically and as input to computational methods. This study introduces a new route to fabricating composite wires with longitudinally varying composition using the byproduct of stationary-shoulder friction stir channelling (SS-FSC); this sample format is attractive for a variety of rapid read-out options in the future. The concept is illustrated by preparing Mg composite wires with a longitudinally graded concentration of SiC-particles. Spark plasma sintering (SPS) was used to encode a step-change in SiC concentration within a feedstock billet. Subsequent SS-FSC transformed this discrete compositional step into a continuous, graded extruded wire. Microstructural analysis revealed significant grain refinement from the SPS billet (44.3 ± 2.3 µm) to the SS-FSC wire (7.4 ± 0.5 µm), with even finer grains in SiC-loaded regions (5.1 ± 0.5 µm), attributed to particle-stimulated nucleation. Mechanical characterisation confirmed a hardness increase, from 65.8 ± 1.2 HV3 to 68.9 ± 2.7 HV3 (high SiC-content). This proof-of-concept study confirms the effectiveness of SS-FSC in producing high-quality wires with tailored microstructural and mechanical gradients. Additional compositions could be readily multiplexed in the original billet, providing a robust high-throughput technique for comprehensive structure–property investigations of advanced alloys and composites.