A coupled in-situ measurement of temperature and kinematic fields in Ti-6Al-4V serrated chip formation at micro-scale

• Published in: International journal of machine tools & manufacture 2018-08, Vol.130-131, p.20-35
• Main Authors: Harzallah, M., Pottier, T., Gilblas, R., Landon, Y., Mousseigne, M., Senatore, J.
• Format: Article
• Language: English
• Subjects: Calibration; Chip formation; Cutting speed; Diffusion rate; Digital image correlation; Engineering Sciences; Experiments; Fast imaging; Infrared imagery; Infrared thermography; Kinematics; Measurement; Micro scale; Optical distortion; Optics; Post-processing; Primary shear zone; Spectrum analysis; Strain rate; Temperature; Titanium base alloys; Visible spectrum
• ISSN: 0890-6955; 1879-2170
• DOI: 10.1016/j.ijmachtools.2018.03.003

The present paper describes and uses a novel bi-spectral imaging apparatus dedicated to the simultaneaous measurement of kinematic and thermal fields in orthogonal cutting experiment. Based on wavelength splitting, this device is used to image small scale phenomenon (about 500×500μm area) involved in the generation of serrated chips from Ti-6Al-4V titanium alloy. Small to moderate cutting speeds are investigated at 6000 images per second for visible spectrum and 600 images per second for infrared measuresments. It allows to obtain unblurred images. A specific attention is paid to calibration issue including optical distortion correction, thermal calibration and data mapping. A complex post-processing procedure based on DIC and direct solution of the heat diffusion equation is detailed in order to obtain strain, strain-rate, temperature and dissipation fields from raw data in a finite strains framework. Finally a discussion is addressed and closely analyzes the obtained results in order to improve the understanding of the segment generation problem from a kinemtatic standpoint but also for the first time from an energetic standpoint. •Coupled measurement of kinematic and thermal fields at tool tip are presented.•The strain mechanisms are strongly affected by the cutting speed.•The heat generated is mainly generated in the primary shear zone.•The cutting temperature is strongly heterogeneous at the tool tip vicinity.•The cutting temperature do not rise linearly with the cutting speed.