Effect of coating type on dry cutting of glass/epoxy composite

This work aims to investigate the effect of coating type on the properties of both fiber and matrix phases when dry cutting glass/epoxy composites. The cutting experiments were performed on three different specimens with glass fibers oriented at 0°, 45°, and 90° with respect to the cutting direction. Uncoated tungsten carbide (WC), CVD monolayer diamond coated (CVD MNL) and CVD multi-layers titanium carbonitride/ceramic/titanium nitride coated (CVD MTL) inserts were used to conduct orthogonal cutting tests. Nano-scale analyses using Atomic Force Microscope (AFM) were performed to evaluate the interface consumption within the tool/phase pairs. Scanning Electronic Microscope (SEM) was employed to inspect the tool wear patterns. The thrust force was measured and correlated with the wear generated on the tool flank face. The CVD MTL coated tool showed better ability to dissipate the thermo-mechanical cutting energy due to the good adhesion of the coating layer to the substrate. This acts to prevent catastrophic failure to the detriment of progressive wear compared to MNL coating. Scanning thermal analysis of fiber and matrix within the surface finish indicated that the thermal conductivity of each of phases is proportional to wear. AFM micro-scratch tests using sliding contact probe revealed that the friction at surface finish strongly depends on the multiplicity of rough asperities favoring hence the thermal conduction on wear track.