In the discussion of the background that follows, reference is made to certain structures and/or methods. However, the following references should not be construed as an admission that these structures and/or methods constitute prior art. Applicant expressly reserves the right to demonstrate that such structures and/or methods do not qualify as prior art.
Currently available tool materials use nitrides or carbides of Ti, mixed with cubic boron nitride (cBN), to form a sintered compact. At speeds greater than 200 m/min, in continuous cutting of materials such as hard steel (greater than about 45-50 HRC), frictional heat can cause rapid wear of current tool materials. Adding heat resistant ceramic, such as TiN, can improve performance in continuous cutting, but at the expense of reduced fracture toughness. Reduced fracture toughness can become a problem in interrupted cutting because the tool fails by chipping. Thus, there is a need to provide a tool material that can machine hard steel parts (>45 HRC) at greater speeds and for longer than is currently possible.