Towards Quantitative Understanding of the Particle-Substrate Bonding During Supersonic Microparticle Impacts
Veera Panova, Massachusetts Institute of Technology
Fundamental understanding of metallic bonding at the substrate-particle interface is crucial for evaluating engineering performance of the parts produced by cold spray. Our recent works have aimed at developing quantitative understanding of particle bonding through the use of the in-situ imaging capabilities of laser-induced particle impact tests (LIPIT) and microstructural characterization using advanced microscopy techniques. The single-particle approach allows systematic exploration of the state of bonding under carefully controlled conditions and reveals the increase in bonding above the critical adhesion velocity as well as a subsequent decrease in bonding at higher velocities closer to the erosion region. Various approaches to quantitatively assess the fraction of area that is bonded are described, and experimental influences on that bonding fraction are subsequently explored. By combining single-particle experiments with advanced microscopy characterization, we are able to evaluate the morphology of the bonding interface and gain insights into the mechanism behind this complex process.