Modeling and experimental study of different discontinuous micro-grinding tools

In this paper, two different types of discontinuous micro-grinding tools are designed and fabricated, which respectively are straight-type effective units (STR) tool and screw-type effective units (SC) tool, and the number of effective grinding zones is designed as three and four respectively. The grinding mechanism between the workpiece and the abrasive grains of discontinuous micro-grinding tools is studied. Grinding force model of two different types of discontinuous micro-grinding tools is established. In order to verify the correctness of the grinding force model and the superiority of the designed discontinuous micro-grinding tools, a series of contrast experiments between the designed discontinuous micro-grinding tools and regular cylindrical (RC) micro-grinding tool are designed. It is experimentally and then theoretically validated that grinding forces of discontinuous micro-grinding tools are much lower than RC grinding tool. Besides, the grinding force amplitude and the grinding force fluctuation degree of RC tool are greater than that of the four kinds of discontinuous micro-grinding tools. Besides, because the discontinuous micro-grinding tools have good ability of chip removal and chip capacity, the machined surface quality of the four-SC micro-grinding tools is better than that of the RC grinding tool with the increase of feeding velocity. Meanwhile, the fabricated four different types of discontinuous micro-grinding tools were compared in terms of tool wear, workpiece surface quality, and grinding force. Among them, chip removal ability of the four-SC grinding tool is superior to the other micro-grinding tools; therefore, the four-screw-type effective units grinding tool own a better tool wear-resisting property, a longer tool life.