A CHROMIUM-CONTAINING COATING, A METHOD FOR ITS PRODUCTION AND A COATED OBJECT
First Claim
1. 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 crystalline phase or phases of chromium (Cr) and/or Cr compounds, Cr being electroplated from a trivalent chromium bath, characterized in that the coating 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.
1 Assignment
0 Petitions
Accused Products
Abstract
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.
-
Citations
32 Claims
- 1. 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 crystalline phase or phases of chromium (Cr) and/or Cr compounds, Cr being electroplated from a trivalent chromium bath, characterized in that the coating 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.
-
17. A method for producing a chromium-based coating on an object by trivalent chromium plating, the method comprising the steps of
a) depositing a layer of nickel phosphorus alloy (NiP) on the object; -
b) depositing a layer of chromium from a trivalent chromium bath on the object; and c) subjecting the coated object to at least one heat treatment at a temperature of 650-950°
C., preferably at a temperature of 750-900°
C., to amend the mechanical and physical properties of the coating and to produce a CrNiP phase. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
-
Specification