Wear Mechanisms of Coated Carbide Tools in Dry Boring of Titanium Alloys

This paper deals with an experimental research on the wear mechanism of coated carbide tools in dry boring of the titanium alloys TC11 which are commonly used for aero-engines. The wear mechanism of coated tool inserts was investigated at various combinations of cutting speed, feed rate, and depth of cut. Analysis carried out with the SEM suggests that adhesive wear and coating delamination are the dominant wear mechanisms under low speed and feed rate and depth of cut; while chipping and breakage are the dominant wear mechanisms for the combinations of high cutting speed, feed rate, and depth of cut. There was no observation of oxygen existing based on the analysis of SEM which indicated no oxidation wear generated during the boring machining. The excellent chemical stability of TiAlN coating and oxidation resistance performance made contribution to prevent oxidation wear. Another reason was that boring temperature was lower than oxidation temperature.