Flank wear of multi-layer coated tool

Flank wear analysis on the multi-layer (TiCN/Al2O3/TiCN) coated carbide inserts has been performed after turning AISI 1045 steel. Using advanced microscope and image processing techniques including wavelet transform, we have obtained the flank wear profiles and analyzed the surface roughness and groove sizes on the coating layers to understand the progress of flank wear and its wear mechanisms. The dominant wear mechanism was found to be the abrasion by the cementite phase in the work material. The adhesion took over after carbide substrate was exposed as the notch wear also became more significant. Based on the experimental result, it was concluded that the hardness of the coating is the most important requirement to resist flank wear due to its high wear resistance against abrasion. Therefore, the multilayer coating scheme does not provide any significant benefit to resist flank wear.

► Using confocal microscope, the progress of flank wear has been studied on multi-layer coated carbide tools.
► Tool wear patterns have been analyzed using wavelet transformation, which enable us to understand the development of flank wear on multi-layer coated carbide tools.
► Based on the observation, we have identified the mechanisms involved in tool wear. This paper challenges the established reason for the benefit of having multi-layer cutting tools. At least, for flank wear, the multi-layer scheme does not help to prolong the tool life. It is better to have a single thick hard coating than the coating in a multi-layer scheme.