Influence of pulsed laser ablation on the surface integrity of PCBN cutting tool materials

• Published in: International journal of advanced manufacturing technology 2019-04, Vol.101 (5-8), p.1687-1698
• Main Authors: Denkena, Berend, Krödel, Alexander, Grove, Thilo
• Format: Article
• Language: English
• Subjects: Ablation; Ablative materials; Boron; Boron oxides; CAE) and Design; Computer-Aided Engineering (CAD; Cubic boron nitride; Cubic lattice; Cutting tool materials; Cutting tools; Engineering; Fluence; Hexagonal lattice; Industrial and Production Engineering; Laser ablation; Lasers; Machining; Mechanical Engineering; Media Management; Nickel base alloys; Original Article; Phase transitions; Pulse duration; Pulsed lasers; Raman spectroscopy; Recrystallization; Superalloys; Surface hardness; Surface properties
• ISSN: 0268-3768; 1433-3015
• DOI: 10.1007/s00170-018-3032-4

Polycrystalline cubic boron nitride (PCBN) is widely used in industry as a cutting tool material for the machining of hardened steels, cast, or nickel-based super alloys. For the generation of geometrical features of such tools, laser ablation is a novel and promising technology, which offers wear-free processing, high automation potential, and geometrical flexibility. In this study, the ablation mechanism is experimentally investigated for a wide range of laser pulse durations (fs-ns regime) and laser-induced effects on the surface properties are presented. It could be shown by using Raman spectroscopy that laser-induced transformations of cubic boron nitride to the hexagonal lattice structure (hBN) or boron oxide (B 2 O 3 ) are strongly determined by the single pulse and areal fluence of the laser source. Furthermore, a pulse duration of few picoseconds or below reduces the thermally induced phase transformations. Moreover, it was shown that the use of ns-laser leads to significant melting and recrystallization processes of the binder material, which reduces surface hardness. This mechanism was not found for the use of fs- and ps-laser sources.