レーザー誘起粒子射出法の開発と高ひずみ速度域における塑性変形挙動

抄録

It is well known that plastic deformation behavior of metallic material depends on the length-scale and time-scale due to dislocation motions in material. The plasticity affected by scale down and higher strain rate is still open to discuss. In other words, both size effect and strain rate effect are critical issue for plasticity. Macro-scale experiment of bulk materials for higher strain rate have been well established. On the other hand, experiment of the micro and nano scales with higher strain rate has not been established. This study developed an experimental method to conduct micro-particle collisions, causing high strain rate deformation on the target materials surface. This is called laser-induced projectile impact test (LIPIT), which is impact indentation test. Due to laser ablation, we could successfully project micro-particles, resulting in particle collision with the material surface at higher strain rate. By changing the laser energy, the indentation crater depth can be changed. We established an impact testing method which is capable of higher strain rate at micro-scale. In addition, finite element method (FEM) was carried out to simulate the plastic deformation behavior due to particle collision at higher strain rate, so that we investigate plastic deformation behavior at the micro scale under higher strain rate.