Suppression of notch wear of a whisker reinforced ceramic tool in air-jet-assisted high-speed machining of Inconel 718

• AJA machining extends the life of a SiC whisker reinforced ceramic tool dramatically.
• Notch of the ceramic tool in machining Inconel 718 is largely reduced by AJA method.
• Tribochemical reaction between SiC and water is a possible reason for wear reduction.
• CFD analysis shows that air jet pushes the coolant toward the tool tip.

This paper describes the notch and flank wear specific to a SiC whisker reinforced alumina tool in air jet assisted (AJA) turning of nickel-base superalloy Inconel 718 at high cutting speeds. An AJA machining experiment has revealed that the air jet applied to the tool tip in addition to coolant dramatically reduces the depth-of-cut notch wear. As a result, the width of flank wear, but not the size of notch wear, determined the life of a ceramic tool in AJA machining of Inconel 718. This is a reason for the large extension and small variation of the tool life when high speed AJA machining is adopted. The maximum tool life length reached 2160 m at a cutting speed of 660 m/min under the given cutting conditions. Finally, the mechanisms of the notch and flank wear of a SiC whisker reinforced alumina tool in AJA machining are discussed from the viewpoints of tribochemical reactions and tool wear anisotropy.