TITANIUM MATERIAL OR TITANIUM ALLOY MATERIAL HAVING SURFACE ELECTRICAL CONDUCTIVITY, AND FUEL CELL SEPARATOR AND FUEL CELL USING THE SAME

摘要

The composition ratio of a titanium hydride [ITi—H/(ITi+ITi—H)]×100 found from the maximum intensity of metal titanium (ITi) and the maximum intensity of the titanium hydride (ITi—H) of the X-ray diffraction peaks measured at a surface of a titanium or a titanium alloy at an incident angle to the surface of 0.3° is 55% or more, a titanium oxide film is formed on an outermost surface of the titanium or the titanium alloy, and C is at 10 atomic % or less, N is at 1 atomic % or less, and B is at 1 atomic % or less in a position where the surface has been subjected to sputtering of 5 nm with argon. The titanium oxide film is formed by performing stabilization treatment after performing passivation treatment in prescribed aqueous solutions, and has a thickness of 3 to 10 nm.

主权项

1. A titanium material or a titanium alloy material, wherein
the composition ratio of a titanium hydride [ITi—H/ITi+ITi—H)]×100 found from the maximum intensity of metal titanium (ITi) and the maximum intensity of the titanium hydride (ITi—H) of the X-ray diffraction peaks measured at a surface of a titanium or a titanium alloy at an incident angle to the surface of 0.3° is 55% or more, a titanium oxide film is formed on an outermost surface of the titanium or the titanium alloy, C is at 10 atomic % or less, N is at 1 atomic % or less, and B is at 1 atomic % or less in a position where the surface has been subjected to sputtering of 5 nm with argon, and each of the amounts of increase in contact resistance from before to after deterioration test 1 and deterioration test 2 below is 10 mΩ cm2 or less, deterioration test 1: immersion for 4 days in a sulfuric acid solution at 80° C. and pH 3 containing 2 ppm F ions, deterioration test 2: application of an electric potential of 1.0 V (vs. SHE) for 24 hours in a sulfuric acid solution at 80° C. and pH 3.