Ball-end micro-milling of material measures: wear behavior in field use

Micro-milling is a precise method for micro-structuring component surfaces. When complex or free-form structures like material measures are to be manufactured, ball-end milling tools are particularly suitable. In preliminary studies by the authors, areal material measures for the calibration of optical topography measuring instruments were manufactured via micro-milling. The demands on the surface quality of the material measures are extremely high. Therefore, worn tools must not be used if the wear has a direct effect on the resulting topography of the manufactured material measures. At the same time, the micro-milling tools used are very costly and should therefore be used as long as possible. A comprehensive experimental study was carried out on the wear behavior of different ball-end micro-milling tools for the specific use case of areal material measures. In the investigations, brass CuZn39Pb3 was machined and different areal material measures were manufactured. The tool life dependent wear was determined and critical wear was identified.