COMPARISON OF ABRASION MODEL TEST-RESULTS AND MACHINING TESTS WITH PVD-COATED INDEXABLE INSERTS

The development of physical vapour deposition (PVD) coatings for improved wear resistance of cutting tools now is addressing more complex coating systems. For example, this is verified by the fact that most of the commercial PVD coating companies now are offering ternary coating systems, such as TiAlN or Ti(C, N), in addition to the standard TiN. Quaternary and quinternary systems are in development. While developing these new coating systems, more parameters have to be optimized which is resulting in larger series of experimental runs. Because it is impossible to consider all the coating variations in machining tests under real turning or milling conditions, it has to be proved how far model wear tests can help in preselecting the coatings with a good potential to perform successfully. The fact that model tests are able only to prove a single wear mechanism needs very careful verification. In this paper, we compare the results of turning or milling tests using TiN-, TiCN-, TiZrN-, ZrCN-and TiZrCN-coated tools with the results of abrasive wear tests. It is shown how far the model test result can give information about the potential of a coating in special cutting conditions, if the whole tribological system with the other affecting factors is to be evaluated.