| 摘要 |
Process for chemical deposition, in the vapour phase, of titanium nickelide, on the surface of metal objects made of nickel or of nickel-based alloys. The invention consists of a process for chemical coating, in halide vapour phase, of the surface of metal objects made of nickel or of nickel alloys or of ferrous metallic materials coated beforehand with nickel by electrolytic or chemical methods, resulting in the formation of a single-phase surface layer of titanium nickelide, of hexagonal structure and of high hardness (close to 1200 Hv 0.025), and of a diffusion sublayer, characterised by a gaseous case-hardening under argon atmosphere at a temperature of between 500 and 1100 DEG C, the cement consisting of metallic titanium in fragmented form, to which is added a proportion of ammonium chloride of between 0.3 and 0.7 % by weight. The coating process according to the invention applies both to metal objects made of nickel, to objects made of nickel alloys and also to any ferrous metallic materials coated with nickel beforehand by electrolytic or chemical methods.
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