Metallurgical aspects of chip morphology control in machining of steel

摘要

The influence of workpiece microstructure on chip morphology was investigated using a number of iron alloys both in the hardened and unhardened condition. Previous work has shown the importance of work-hardening capacity of the alloy in serrated chip formation through shear angle rotationin the primary shear zone within each periodic cycle of serration. In the present work, the approach is extended to include the effects of matrix hardening (thermal softening potential), second phase particles (geometric softening potential), temperature corrected strain rate (cutting speed and feed) and tribological conditions of seizure at the tool-chip interface. The mechanism of shear localised chip formation and its consequences on tool wear are discussed.