Material Microstructure Effect-based Investigation of Tool Wear in Micro-endmilling of Multi-phase Materials

This paper presents an investigation of the microstructure effects of multi-phase materials on tool wear at microscale machining. A new generic method is developed to estimate the tool wear when machining multi-phase materials. The average values of cutting edge radius and tool flute profile were used to estimate the tool wear. A new experimental setup was proposed to determine these two parameters, and series of experiments on two materials with distinctive properties were conducted in order to assess the validity of the proposed method. Especially, the machining response of pearlite and ferrite were studied independently to capture differences in their cutting conditions, and thus to model the effects of each phase on the tool wear. Then, based on the experimental data two regression models were created to estimate the increase of the cutting edge radius for pearlite and ferrite steel independently. To demonstrate the applicability of the proposed generic method and at the same time to validate the models, they were used to estimate the tool wear of AISI1040 as an example of dual-phase steel. A good agreement between the estimated tool wear and the experimental results was obtained; the average error was 17.9%. This empirical study demonstrates the validity of the proposed generic method for estimating the tool wear when machining multi-phase materials.