Abstract
Single- and multilayer coated inserts were fully characterized by chemical analysis and metallography before monitoring their wear behaviour under high-speed machining conditions when turning annealed En 24 steel. The multilayer insert showed superior behaviour in resisting both flank and crater wear. Examination of worn inserts using Auger electron spectroscopy and scanning electron microscopy indicated that similar wear mechanisms operated for the different coated inserts. The reasons for the improved behaviour of multilayer coatings are discussed.