Polycrystalline cubic boron nitride (PCBN) tool life and wear in turning of amorphous-crystalline iron-based coatings

Abstract

The paper presents PCBN-Ciborit cutting tools life and wear test results. The effects of the machining regime when turning amorphous-crystalline Fe 80B 20 and Fe 79Cr 16B 5 coating systems applied to conventional workpiece materials were assessed. It has been shown that the observed tool wear mechanisms are complex in their character and are dominated by abrasive-mechanical, adhesive and chemical effects in the cutting zone. Under changing turning conditions tool life is affected by the structural-phase composition and by the non-homogeneous structure of the coating. Specifically, when turning gas-flame coatings deposited with a Fe 80B 20 electrode and electro-arc coatings with a Fe 79Cr 16B 5 electrode the lowest wear and the highest tool life was achieved at cutting speeds of v = 1.1 to 1.2 m/s and a back rake angle of γ = -10°. It has been demonstrated that a change of the back rake angle from γ = 0 to -10° does not have a great effect on tool life contrary to the case with . = -20°. © 2011 Journal of Mechanical Engineering.