Structure and properties of PVD coated PM high-speed steels

The paper presents results of investigations concerning structure and properties of TiN and Ti(C,N) coatings deposited onto PM high speed steels of the P 6-5-3 and P 6-5-3-8 types produced by the ASEA-Stora process. It has been confirmed that TiN and Ti(C,N) coatings had very good adherence to the substrate, low friction coefficient and high hardness. The structure of coatings is dense and columnar shaped. The erosion resistance of sintered high speed steels coated in the PVD process is extended and limited to the coating material only during the initial period-unlike in the case of uncoated steels where an erosion rate is constant from the very beginning.