Assessment of Tool Wear Based on Surface Texture Parameters

This research presents a new way to determine the condition of a cutting tool based on high definition surface texture parameters. Recently, a laser holographic interferometer has been developed to rapidly measure the whole workpiece surface (e.g. 300mm×300mm) and generate a 3D surface height map with micron level accuracy. This technique enables on-line surface measurement for machined parts. By measuring the surface texture of workpieces, the interaction between the tool’s cutting edges and the surface can be extracted as a spatial signature. It can then be used as a warning sign for tool change because the workpiece produced by a heavily worn tool exhibits more irregularities than those produced by a normal tool. Three surface texture parameters: image intensity histogram, surface peak-to-valley height and surface waviness are employed to detect the onset of severe tool wear. Furthermore, surface waviness can also be used to classify the different phases of tool wear. In this work, nine surface samples under different tool wear phases are created and analyzed using surface texture parameters combined with Statistical Process Control (SPC) charts to assess tool conditions. The results verify that these surface texture parameters can be used for on-line tool wear monitoring.