The formation of a sheared surface is an important factor in punching. The fine-blanking method is known as a method for forming a sheared surface by applying compressive stress to a work material during punching. The element used for continuously variable transmission (CVT) has been put into practical use for fine-blanked carbon steel. Since this element has a different shape and a different plate thickness, there is a problem that compressive stress cannot be sufficiently applied, causing cracks occur during punching. In this study, the shoulder part of the punching die was changed in multiple steps from one step to three steps. The fine-blanked work materials were observed by scanning electron microscope (SEM) and electron backscatter diffraction (EBSD). The damage value was analyzed by the finite element method (FEM). Through these experiments and verifications, we identified a basic phenomenon in the formation of the sheared surface of the element and devised a design guideline for the die shoulder shape. When the punching die shoulder changed to the optimized three-step shape, the work hardening ability was maintained during punching. Then the sheared surface was formed with low plastic strain conditions in the deformed state of the grains.

A new material model based on dislocation dynamics was developed specifically for cold spraying (CS) under supersonic impact conditions. It can adequately capture the following four physical phenomena occurring within nanoseconds: (1) strain hardening, (2) normal-range strain rate hardening, (3) ultrahigh-strain-rate hardening, and (4) thermal softening/hardening. The parameters of the new material model for pure Ni were systematically determined by mathematical fitting. Moreover, a cold spray experiment focusing on a single Ni microparticle was carried out and the particle’s deformation was measured, which agreed well with the simulated one, thereby proving the high accuracy of this material model.