Microstructure evolution of composite during in-situ reaction of aluminum and titanium oxide based on SANS characterization

The high-temperature performance of aluminum matrix composites (AMCs) is pivotal for their applications in extreme environments. This study focuses on a heat-resistant (Al₂O₃+Al₃Ti)/Al composite synthesized via sol-gel and powder metallurgy, leveraging the in-situ reaction between Al and titanium oxide. While previous work demonstrated its exceptional thermal stability, the reaction process remained poorly understood due to limitations in conventional characterization techniques. Here, an integrated multi-scale approach combining small-angle neutron scattering (SANS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) was employed to unravel the reaction dynamics. SANS analysis quantitatively revealed the reaction initiation (580 °C) and completion (620 °C) temperatures, while TEM and SEM identified the sequential formation of Al₂O₃ and Al₃Ti phases. This methodology bridges macro-scale scattering data with atomic-scale microstructural evolution, overcoming statistical limitations of traditional techniques. The findings establish a universal framework for real-time monitoring of nanoscale reactions and microstructure optimization in AMCs, offering critical insights for designing high-performance composites through controlled in-situ synthesis.