Titanium-Nickel Alloy, Method for Modifying Titanium-Nickel Alloy Surface, Biocompatible Material
OwnerTakayuki Yoneyama, Osamu Fukushima +2inventors
InventorsTakayuki Yoneyama, Osamu Fukushima, Takao Hanawa, Hisashi Doi
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Abstract
Provided is a titanium-nickel alloy improved in corrosion resistance due to the reduced Ni content in the surface layer. Since a film (modified layer) extremely reduced in Ni concentration compared to the interior can be formed on the surface of a titanium-nickel alloy, by applying electrolysis treatment in a properly controlled electrolytic solution, the corrosion resistance of the alloy is improved. Specific examples of the electrolytic solution may include a mixture of glycerol, lactic acid and water (H2O).
Claims10
A titanium-nickel alloy having a composition in which titanium and nickel are contained mutually in a molar ratio of 48.5 to 51.5%, characterized in that a modified layer reduced in nickel content compared to the interior is formed on the surface, thereby having corrosion resistance in which current increase due to pitting corrosion is not observed until a voltage of 1300 mV.
(canceled)
A method for modifying the surface of a titanium-nickel alloy comprising the step of electrolyzing a titanium-nickel alloy having a composition in which titanium and nickel are contained mutually in a molar ratio of 48.5 to 51.5%, in an electrolytic solution containing weak acid to form a modified layer reduced in nickel content compared to the interior on the surface, characterized in that the electrolytic solution is composed of 10 vol % to 40 vol % of glycerol, 0.1 vol % to 80 vol % of lactic acid and water (the remainder).
Dependencies are inferred from the claim text.