Multi c-BN Coatings by r.f Diode Sputtering and Investigation of Wear Behavior

Area of Science:

• Materials Science
• Surface Engineering
• Tribology

Background:

• Cubic boron nitride (c-BN) films on tool substrates often suffer from delamination, limiting their application.
• Research focuses on improving c-BN synthesis and deposition for enhanced performance.

Purpose of the Study:

• To investigate the improvement of c-BN layer adhesion by depositing multi c-BN layers.
• To evaluate the performance of multi c-BN layer systems in industrial cutting applications.

Main Methods:

• Multi c-BN layers were deposited using radio frequency (r.f.) diode sputtering on cemented carbide tool substrates with a TiAlN adhesion layer.
• Turning and milling experiments were conducted under dry and high-speed cutting conditions.

Main Results:

• Fine grain size substrates extended tool lifetimes by over 4 times compared to raw substrates.
• Multi c-BN layer systems demonstrated significantly longer tool lifetimes than mono TiAlN layers in turning.
• Improved adhesion properties were observed for milling performance with binary multi c-BN layer systems.

Conclusions:

• Multi c-BN layer systems enhance adhesion and tool lifetime, particularly on fine grain size substrates.
• These findings confirm the high potential of c-BN coatings for cutting tools in demanding applications.