Titanium alloy, separator, and solid polymer fuel cell

Abstract

The invention discloses a titanium alloy, a separator, and a solid polymer fuel cell. Provided is a titanium alloy containing a total of 0.01-0.15 mass% of at least one platinum group element, the remainder comprising titanium, oxygen, and impurities, wherein the titanium alloy includes particles of a compound composed of the at least one platinum group element, titanium, and oxygen, the average size of the particles at the surface of the titanium alloy is 1 [mu]m or less, and the numerical density of the particles at the surface of the titanium alloy is 25 per 1,000 [mu]m2 or greater. This titanium alloy can maintain higher corrosion resistance and lower contact resistance, as compared with a conventional titanium alloy having equivalent platinum group element content.

Description

technical field [0001] The present invention relates to a titanium alloy, a fuel cell separator using the titanium alloy, and a solid polymer fuel cell including the separator. Background technique [0002] Since titanium has excellent corrosion resistance, it is widely used as a material for chemical industry equipment, a material for thermal and nuclear power generation equipment, and a material for seawater desalination equipment. However, the environments where titanium can exhibit high corrosion resistance are limited to oxidizing acid (nitric acid, etc.) environments, neutral chloride environments such as seawater, crevice corrosion resistance in high-temperature chloride environments, and non-oxidizing acid solutions such as hydrochloric acid. The corrosion resistance (hereinafter, also simply referred to as "corrosion resistance") is not sufficient. [0003] In order to solve this problem, titanium alloys in which platinum group elements are contained in titanium ha...

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Problems solved by technology

However, in response to the demand for further improvement in properties in recent years, especially when the content of Pd is less than 0.05% by mass, properties such as corrosion resistance are not sufficient.

[0014] Thus, in the prior art, when the content of Pd is less than 0.05% by mass, it cannot sufficiently meet the demand for further improvement of corrosion resistance.

) surface will be oxidized, which may increase the contact resistance with the gas diffusion layer

[0025] On the other hand, carbon-based materials have the advantage of being able to obtain a lightweight separator due to their small specific gravity, but they have problems such as air permeability and low mechanical strength.

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