Abstract: Micro-grooves on tool rake surface can improve cutting performance, but it is very difficult to perform a micro-machining towards superhard CBN cutter. Thus, a micro-grinding is proposed to fabricate 54 m-height micro-grooves on CBN cutter rake surface for dry cutting of steel. A metal-bonded #600 diamond wheel V-tip is employed to fabricate micro-grooves along different orientations to cutting edge; heat-up experiments are performed to analyze the correlation between rake surface temperature and cutter tip temperature; dry cutting experiments of #45 steel are performed to investigate the effects of micro-groove orientations and cutting conditions on dry cutting temperature. It is shown that the regular and smooth micro-grooves on CBN cutter rake surface may be machined. Rake surface temperature may be used to predict cutter tip temperature because they are very relative. The parallel and diagonal micro-grooves on cutter rake surface produce quicker hear transfer, which can contribute to excluding cutting heat from cutter tip. It is confirmed that parallel micro-grooves on cutter rake surface may decrease dry cutting temperature by 18% compared with traditional plane cutter. However, diagonal and vertical micro-grooves produce the largest cutting temperature because the cutting edge shape due to micro-grooves is changed. In the case of large removal rate, parallel micro-grooved cutter produces much less cutter tip temperature than diagonal and vertical micro-grooved cutters, leading to much less cutter wear.

Key words: micro-grinding;micro-structured arrays;CBN turning tool;dry cutting