Use of Ultra High Speed Imaging to Study Material Deformation during High Speed Machining

摘要

The highest frame rate multi-image sequences currently obtainable (around 200 MHz) are provided by ultra high-speed cameras using image intensifiers. However, the image quality is degraded by the intensifier and it is difficult to perform differential image correlation of the images to obtain accurate deformation maps. Working with vendors of Particle Imaging Velocimetry (PIV) systems, we have developed an idea for a new type of non-intensified high-speed multi-frame camera system using laser illumination. Proof-of-concept testing indicates that this system will be capable of comparable frame rates at much better resolution. Using a demonstration prototype of this system, microscopic images have been acquired at high framing rates (up to 2 MHz). Differential image correlation (DIC) of the images has been used to obtain the strain rate distribution in the primary deformation zone in cutting experiments at speeds up to 7.86 m/s under strain rates greater than 10{sup}5 s{sup}(-1).