Mechanical Behavior of Single Crystal Copper for Different Shearing Directions

The mechanical behavior of the surface of metals is strongly affected by surface fracture occurring in the process of mechanical shearing, especially in shaper-type cutting performed for the application of ultra-fine optical manufacturing and several types of nanotechnology. This discussion aims to elucidate the tribological behavior of pure Cu. In ultra-precise cutting, the physics of crystallographic interfaces is extremely important for controlling surface fracture behavior. In this study, surface fracture behavior was evaluated using single crystal copper cut in two different directions (along the (100) and (111) planes). For V-shaped groove cutting, the flat copper surface was cut with a diamond-tip cutting tool (with a V angle of 90 degrees, a rake angle of 0 degrees, and an escape angle of 7 degrees) at a machining speed of 4-4000 mm/min and a cutting depth of 0.2-10 mu m. The machined surface was observed with a laser scanning microscope and compared with two groove shapes, in which the cutting grooves in the two cutting directions were found to be different. This result was considered to depend on whether the cutting tool moved along the slip planes {111}, which are oriented in the <1 <(1)over bar> 0> direction. In the case of shallow cutting (under 1 mu m), the springback behavior became apparent for cutting in the slip plane direction, where the mechanism of this behavior would be associated with the interface between slip-plane fractures created by the cutting tool.