THE PERFORMANCE OF (TI,AL)N-COATED FLOWDRILLS

Abstract

The oxidation resistance of (Ti,Al)N coatings at elevated temperatures makes them suitable for applications where other coatings fail. Results about the performance of (Ti,Al)N coatings at elevated temperatures have been published for metal cutting operations, but much less is known about the behaviour of (Ti,Al)N-coated tools in contact with molten metals. Uncoated cemented carbide flowdrills were compared with (Ti,Al)N coated flowdrills. Respectively about 5000 holes and over 100 000 holes in austenitic stainless steel AISI 304 have been produced. The tool wear and the deposition of workpiece material on the tool were examined by means of scanning electron microscopy and energy-dispersive X-ray analysis. In particular, the influence of these deposits on the tool life is discussed.