Residual Stress Development in Laser Machined PVD-Coated Carbide Cutting Tools

Residual Stress Development in Laser Machined PVD-Coated Carbide Cutting Tools

Categories Zeitschriften/Aufsätze (reviewed)
Year 2013
Authors Denkena, B., Breidenstein, B., Gey, C.:
Published In Materials Science Forum, Vols. 768-769 (2014), S. 391-397.

There is growing interest in laser machining as an alternative to abrasive processes for creating cutting tool micro geometries. This technology is also suitable for creating micro geometries on cutting edges of superhard cutting tools. The pulsed nanosecond lasers, which are commonly used for this type of application, induce high thermal loads in the tool. This heat is believed to cause temperature gradients which result in tensile residual stresses at the cutting edge surface. They are generally unfavorable for the cutting tool performance because of the tendency to crack formation and propagation. Different levels of compressive residual stress are observed after each step (sintering, grinding, shot peening, etching and PVD-coating). From investigations of commercial processes for manufacturing PVD-coated carbide cutting tools it is known that the final residual stress state of the carbide subsurface is a result of the superposition of the stress states resulting from the individual process steps. In contrast to that, laser machining is expected to produce tensile residual stress due to the temperature gradient. The present work describes the influence of a substitution of grinding by laser machining in the process chain for the production of PVD-coated carbide cutting tools on the residual stress state in the finished tools.

DOI 10.4028/