Processes of treating nickel-phosphorus alloy coatings and the resulting modified coatings

• US 3,088,846 A
• Filed: 01/24/1962
• Issued: 05/07/1963
• Est. Priority Date: 01/24/1962
• Status: Expired due to Term

• Current Assignee: Warren G. Lee
• Original Assignee: Warren G. Lee
• Inventors: Lee, Warren G.
• Application Number:
  US04/168,526
• Time in Patent Office: 468 Days
• US Class Current: 428/628
• CPC Class Codes: C23C 18/36 using hypophosphites
• CPC Class Codes: C23C 22/24 containing hexavalent chromium compounds
• CPC Class Codes: Y10S 428/926 Thickness of individual layer specified
• CPC Class Codes: Y10S 428/936 Chemical deposition, e.g. electroless plating
• CPC Class Codes: Y10T 428/12583 Component contains compound of adjacent metal
• CPC Class Codes: Y10T 428/1275 Next to Group VIII or IB metal-base component
• CPC Class Codes: Y10T 428/24967 Absolute thicknesses specified
• CPC Class Codes: Y10T 428/261 In terms of molecular thickness or light wave length
• CPC Class Codes: Y10T 428/31678 Of metal

Claims

1. THE PROCESS OF INCREASING THE CORROSION RESISTANCE OF NICKEL-PHOSPHORUS COATING CARRIED BY A METAL WORKPIECE AND APPLIED THERETO BY CHEMICAL PLATING FROM AN AQUEOUS PLATING BATH OF NICKEL CATION-HYPOPHOSPHITE ANION TYPE, WHEREIN SAID COATING COMPRISES BY WEIGHT ABOUT 85% TO 97% NICKEL AND ABOUT 3% TO 15% PHOSPHORUS;

SAID PROCESS COMPRISING EMMERSING SAID COATED WORKPIECE DURING A SUITABLE TIME INTERVAL IN A TREATMENT BATH SAID TREATMENT BATH ESSENTIALLY COMPRISING AN AQUEOUS SOLUTION OF A WATER SOLUBLE COMPOUND SELECTED FROM THE CLASS CONSISTING OF CHROMIC ACID ANHYDRIDE, ALKALI METAL CHROMATE AND ALKALI METAL DICHROMATE, SAID TREATMENT BATH CONTAINING BY WEIGHT AT LEAST ABOUT 1 2% CHROMATE IONS.