SUBSTRATE COATING FOR GENERATING GOOD TRIBOLOGICAL PROPERTIES IN CHROME-NITROGEN ALLOYS AND PROCESS FOR OBTAINING THE SAME

摘要

The substrate coating of the invention is intended to give the substrate good tribological properties and consists of an alloy of chromium and nitrogen containing, for 100 atoms, from 87 to 68 atoms of chromium and 13 to 32 atoms of 'nitrogen. This alloy is biphase, with a phase of cubic microcrystalline chromium containing nitrogen included and a phase of a quadratic chromium nitride in stoichiometric defect compared to the nitride Cr2 N. The ratio of the lattice parameters of this quadratic nitride is understood between 1.02 and 1.5. This quadratic nitride was unknown until now, and can probably only exist in association with chromium. It resists wear up to 5 times better than the known single-phase chromium-nitrogen alloys, and does not exhibit the inherent brittleness of biphase alloys containing hexagonal Cr2 N nitride. BR/ These coatings are obtained by chromium magnetron sputtering, with a partial pressure of nitrogen in an atmosphere of rare gas between a maximum and a minimum determined experimentally.