Abstract Scope |
Microparticle impacts such as micrometeorite collisions or cold spray adaptive manufacturing create an extreme loading environment in the projectile and target bodies. Plastic deformation in metals is controlled by the complex motion and evolution of dislocations within the crystal lattice. Propagating shock waves cause a wide range of stain rates from quasi-static to rates in excess of 108 s-1. To accurately capture the material response, a flow stress model that precisely captures both the thermal barriers to dislocation motion, during low-rate loading, and phonon drag effects, during high-rate loading, is needed. Additionally, a complex network of evolving mobile and immobile dislocations must be represented. In this work, the recently developed mean first passage time model (MFPT) along with an analytical model for the generation, storage, and annihilation of dislocations, developed by Hunter and Preston, is used to simulate metallic polycrystalline microparticle impacts. |