Tool wear as-modified by particle generation in dry machining

Abstract

This paper deals with the relationship between wear resistance of diamond tools and the emission of particles while machining metal matrix composites reinforced with silicon carbides particles. Metal matrix composite is a difficult to machine material. Due to abrasive action of the reinforcement, diamond tool seems to be the more appropriate tool. Nanostructured diamond coated tool and various PCD tools were used in this study to investigate their wear resistance and their impact on particle generation. Bar turning tests were conducted on aluminum alloy reinforced with different level of particles (0, 15, 25 and 35% of SiCp). Airborne particles were measured in situ with a spectrometer and sorted in 15 size channels each six seconds. Morphology of chip and tool rake face was observed. The quantity of particles and the metrology of the airborne aerosol were linked for each tool and each level of reinforcement to tool wear resistance and chip morphology. The increase of particle size is associated to extraction of SiC particles from chip on shear plane and form workpiece material, whereas the increase of quantity of particles corresponds to diamond grains removed due to abrasive wear mode. Tool behaviour had important effect on aerosol metrology and on its consequences on airway if inhaled.