Claims
- 1. A black chromium electroplating process comprising immersing an anode and a cathode of electrically conductive material to be plated in a plating bath comprising 70 to 1000 g of dissolved chromium trioxide per liter and a radioactive substance selected from the group consisting of a hydroxide, halide, nitrate or acetate of thorium or uranium in an amount of 7.times.10.sup.-2 to 7.times.10.sup.-1 .mu.Ci per 100 parts by weight of chromium trioxide contained in the bath and passing a D.C. current between the anode and the cathode to plate the cathode with a black chromium coating.
- 2. A black chromium electroplating process comprising immersing an anode and a cathode of electrically conductive material to be plated in a plating bath comprising an aqueous solution of chromium trioxide, adding to the bath at least one radioactive substance selected from the group consisting of hydroxides, halides, nitrates and acetates of thorium and uranium, passing a D.C. current between the cathode and the anode to plate the cathode with a chromium coating and activating hexavalent chromium ions present in said bath to cause the chromium coating resulting from said electroplating to be black by the radioactive emissions from said radioactive substance present in said bath.
- 3. A black chromium electroplating process comprising immersing an anode and a cathode of electrically conductive material to be plated in a plating bath comprising 70 to 1000 g. of dissolved chromium trioxide per liter, passing a DC current between the anode and the cathode and during plating applying to the plating bath radiation selected from the group consisting of x-rays, electron accelerator rays and radiations from cobalt 60, cesium 137 and strontium 90 emitted from a radiation source disposed outside said plating bath to provide a black chromium coating on said cathode, the dose of said group radiation being 1.5 to 20 .mu.rad.
Parent Case Info
This is a continuation of application Ser. No. 631,178, filed Nov. 11, 1975 now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3311548 |
Brown et al. |
Mar 1967 |
|
3909404 |
Boycott |
Sep 1975 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
624887 |
Aug 1961 |
CAX |
Continuations (1)
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Number |
Date |
Country |
Parent |
631178 |
Nov 1975 |
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