Development and application of TiC-Ni-based plasma sprayed coatings

This paper describes results of fundamental studies of APS for different alloying steps in the production of TiC-based coatings from agglomerated and sintered powders and results of application of APS coatings on piston rings. APS is, besides DGS and HVOF, a suitable technology for producing such coatings. The introduction of nitrogen into the hard phase does not result in an increase of dry abrasion wear resistance for APS coatings, but has a significant effect on coating wear when used as a piston ring coating in a passenger car engine. If spraying is done by APS, it is economic advantage that Ar/H2 plasma gases can be used for reaching optimum results instead of Ar/He, which must be used for WC-Co or Cr3C2-NiCr. With respect to dry abrasive wear, TiC-based coatings are fully competitive with commercially introduced systems and can be compositionally tailored for use in simultaneously abrasive and corrosive media.