• Introduce Laser Ablation, Particle Acceleration and Observation (LAPAO). • Study single particle impacts for spherical Al2O3. • Propose new deposition characteristics for spherical Al2O3. • Study single particle impacts for angular Al2O3. • Propose new deposition characteristics for angular Al2O3. Metal matrix composites (MMCs) are an important branch of materials capable of being manufactured using cold spray. These coatings comprise of metal powders mixed with a low weight percentage of ceramic powders which act as a reinforcement for the metallic coating, which in turn improve its mechanical properties. Previously, numerical studies have been utilized to better understand the ceramic-substrate interaction, specifically fragmentation which is considered necessary for ceramic particle deposition in metallic substrates. However, these studies have been restricted to spherical powder morphologies which are less common in MMCs. In this work, Laser Ablation, Particle Acceleration and Observation (LAPAO) is used to study the fragmentation and embedment velocities of alumina particles as they impact aluminium substrates to better understand how the coating-substrate interface can be improved in Al-Al2O3 MMCs. Through varying particle size, morphology and velocity, a better understanding of the primary mechanism behind ceramic particle embedment is gained, concluding that spherical ceramic particles fragmentation and embedment are less dependent on velocity, but more dependent on irregularities formed during the powder fabrication process. Additionally, angular ceramic particles fragment and embed at much lower velocities making them much more suitable for the fabrication of MMCs.
Devlin et al. (2026) studied this question.