Effect of Strain Rate on Microstructure Evolution and Compressive Deformation Behavior of High Strength Copper Coating Materials Fabricated by the Kinetic Spray Process

The effects of strain rates on the compressive deformation behavior of pure copper materials manufactured using kinetic spray processes were presented. The deformed microstructures that change according to strain rates were also analyzed. Pure copper materials manufactured through kinetic spraying showed distinctive structures wherein high-density dislocation structures had been accumulated because individual powder particles collided at high speed. These materials showed very high compressive yield strength and low strain rate sensitivity. In low strain rate conditions, even dynamic recovery occurred in internal dislocation structures, thereby showing strain softening phenomena even at room temperature. On the other hand, in high strain rate conditions, strain localization occurred similarly to general severe plastic deformed materials, exhibiting deformation hardening phenomena. It could be seen that kinetic spray processes make for a new process through which materials with excellent mechanical properties can be manufactured. (supported by "the program for the Training of Graduate Students in Regional Innovation", Korea)