Method of making a trivalent chromium plated engine valve
First Claim
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1. A method for providing a wear resistant chromium coating on a metallic internal combustion engine valve stem, said method including the steps of:
- (a) electro-depositing a coating made solely from trivalent chromium ions and devoid of hexavalent chromium ions on the valve stem and,(b) heating the coating of step (a) to a temperature of at least about 150°
F. for at least about 30 minutes.
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Abstract
An internal combustion engine valve (100) is provided having a stem (4) onto which a plating or coating of trivalent chromium is electrodeposited and which is then heated at a temperature of at least about 150° F. for at least about 3 hours to provide a wear resistant surface that is superior to coatings of hexavalent chromium heretofor used for such purpose.
29 Citations
8 Claims
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1. A method for providing a wear resistant chromium coating on a metallic internal combustion engine valve stem, said method including the steps of:
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(a) electro-depositing a coating made solely from trivalent chromium ions and devoid of hexavalent chromium ions on the valve stem and, (b) heating the coating of step (a) to a temperature of at least about 150°
F. for at least about 30 minutes. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A metallic engine valve having a stem having a wear resistant coating of chromium thereon, said chromium having been electro-deposited solely as trivalent chromium ions and devoid of hexavalent chromium ions thereon and then heated at a temperature of at least about 150°
- F. for at least 30 minutes.
Specification