Cubic Boron Nitride Tool Wear in Interrupted Hard Cutting
Y K. Chou, Christopher J. Evans
Cubic boron nitride (CBN) tool wear in interrupted turning of hardened M50 steel has been investigated. The goal was to identify dominant wear mechanism during interrupted cutting, and in particular, to study the effect of CBN content. Results show significantly different wear characteristics between high (CBN-H) and low (CBN-L) CBN content tools. Contrary to Taylor's tool life equation, tool life of CBN-L is optimized at a medium cutting speed. In contrast, CBN-H shows a monotonic decrease of tool life with increasing cutting speed. Moreover, CBN-H is less sensitive to interrupted cutting than CBN-L which shows consistent decrease of tool life with increasing interrupted frequency. It is suggested that the higher hardness and fracture toughness of CBN-H result in greater resistance to mechanical wear that becomes more dominant in interrupted cutting. However, the metallic binder in CBN-H has high affinity with workpiece materials and therefore, results in rapid thermally activated wear at high cutting speeds.
CBN tools, hard turning, interrupted cutting, tool wear
and Evans, C.
Cubic Boron Nitride Tool Wear in Interrupted Hard Cutting, Wear
(Accessed June 3, 2023)