Study on Ultra High Speed Machining (Report 1)

In this paper, the experimental results of ultra high speed machining is reperted. Cutting velocities are reached to 200-700 m/s. We are used a Cal. 30 gun tube (removed rifle) for the purpose of realising these ultra high speeds. Experimental apparatus are composed of a projectile recovery device, a tool holder and a projectile (specimen) firing device. Main cutting forces are measured by a tool dynamometer (semiconductor strain gages are used). The deformed layer under finished surface is investigated by the etch-pit method. As the results, we found out that cutting mechanism is the shearing. There are marked features of chip shapes ; width of chips are widened, length of chips are almost similar to length of cut. There are also some characteristic features on tool wear and finished surface.