Enhanced chip analysis with computed tomography for estimation of chip segmentation frequency

This work presents an enhancement of a method for analyzing metallic chips produced during turning processes in order to estimate the chip segmentation frequency. Therefore, the resulting 3D image of a computer tomography scan of the chip can be transformed virtually into a straight chip by describing the course of the chip in three-dimensional space by a trajectory. Along this trajectory, the chip point cloud is sliced in thin layers which can be transformed to a straight chip. To estimate the segment rate, the height course describing the segmentation of the chip is extracted on the serrated side of the point cloud by means of nearest neighbor interpolation. The resulting signals are compared with the measurements of the chip surface using an optical microscope, whereby only two straight chips could be analyzed. The comparison shows a nearly perfect match between the two signals and is confirmed by a Pearson correlation coefficient of over 86 % for both signals. Furthermore, a statistical comparison with the acoustic emissions of the turning process reveals satisfying similarities for the chip segmentation frequency with respect to the compression factor.