The design of hardmetal substrates for coated cutting tools is a major challenge in the hardmetal production. (Ti,W)C-based functionally graded hardmetals (FGHMs) were produced by sintering in reactive atmosphere and coated with a multilayer coating of the type substrate/TiN/Ti(C,N)/Al_2O_3-ZrO_2. The microstructure of the FGHMs covered a Ti(C,N)-enriched surface and a graded distribution of carbonitride phase towards the bulk. For comparison, also "fcc-phase-free layer" hardmetals were coated and subjected to cutting tests together with the uncoated grades. The cutting tests were performed in dry conditions and showed that 1) uncoated FGHMs are superior to uncoated fcc-phase-free layer hardmetals and 2) the coated FGHMs have superior performance as compared to coated fcc-phase-free layer hardmetals especially at a high cutting speed.
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