摘要:
To produce a chromium-containing multilayer coating on an object, alternate layers of nickel phosphorus alloy and trivalent chromium are deposited on the object until a desired thickness of coating has been reached. The coated object is then subjected to one or more heat treatments to improve the mechanical and physical properties of the coating and to produce multiphase layers comprising layers containing crystalline Ni and crystalline Ni3P and layers containing crystalline Cr.
摘要:
The invention relates to a chromium-based coating comprising at least one layer rich in crystalline phase or phases of nickel (Ni) and/or Ni compounds, and at least one layer rich in crystal-line phase or phases of chromium (Cr) and/or Cr compounds, Cr being electroplated from a trivalent chromium bath. The coating is characterized in that the it further comprises one or more crystalline phases of chromium-nickel-phosphorus (CrNiP), which CrNiP phase has been produced by heat treating a coating comprising at least one layer of nickel-phosphorus (NiP) and at least one layer of Cr. The invention also relates to a method for producing a chromiumbased coating and to a coated object.