CHARACTERIZATION OF TIN-COATED HIGH-SPEED STEEL CUTTING EDGES BY LOAD-INDENTATION MEASUREMENTS

The recently introduced differential load feed (DLF) analysis of load- indentation measurements has been applied to the investigation of the near-edge regions of TiN-coated high speed steel samples. Samples with edge angles of 30 degrees, 54 degrees and 90 degrees were hardened, p olished and coated with TiN under defined deposition conditions by con ventional and unbalanced magnetron sputtering. The indents were set at distances of 10, 50 and 100 mu m from the edge as well as at 5 mm edg e distance on the coated surface. The obtained DLF plots indicate the existence of a property distribution vs. the edge distance. The near-e dge regions showed a marked substrate softening and coating hardening in comparison with the central sample surface regions.