Nippon Steel Corporation

Sintokogio, Ltd.

Other

Nippon Steel Sumitomo Metal Corporation

Sintobrator, Ltd.

Wataru Hisada

Hiroshi Kihira

Michio Kaneko

Koki Tanaka

Mitsuharu Yamagata

Yoichi Ikematsu

Yoichi Matsuzaki

Kazuto Kawakami

Youichi Ikematsu

Tamotsu Itoh

Suguru Suzuki

Kazuhiro Takahashi

Kiyonori Tokuno

Mitsuo Shintani

Manabu Yamaguchi

Yoshiki Aramatsu

The present invention provides a polymer electrolyte fuel cell separator made of pure titanium or a titanium alloy superior in contact resistance with carbon paper and a method of production of the same, that is, a separator having a surface layer part to which conductive compound particles are affixed, characterized in that the surface oxide has a thickness of 3 to 15 nm in range, an average carbon concentration in a range from an outermost surface, including the oxide layer, to a depth of 100 nm is 0.02 to 6 at %, and the conductive compound particles have an average particle size of 0.01 to 20 &#x3bc;m. Further, the method of production of the present invention is characterized by forming, blast treating a surface of the formed article by particles comprised of conductive compound particles of an average particle size of 0.01 to 20 &#x3bc;m covering a surface of superhard core particles, impregnating it by a nitric acid aqueous solution of a concentration of 15 to 71 mass % and a temperature of 40 to 100&#xb0; C. for 30 seconds to 180 minutes by spraying or dipping, then washing it.

Polymer electrolyte fuel cell separator made of pure titanium or titanium alloy and method of production of same

The present invention provides a method of production of a separator for a solid polymer type fuel cell characterized by shaping a substrate comprised of stainless steel, titanium, or a titanium alloy and then spraying the substrate surface with superhard core particles comprised of conductive compound particles of an average particle size of 0.01 to 20 &#x3bc;m mixed with a coating material and coated on their surfaces under conditions of a spray pressure of 0.4 MPa or less and a spray amount per cmof the substrate of 10 to 100 g in blast treatment. The ratio of the conductive compound to the mass of the core particles is 0.5 to 15 mass %.

Solid polymer type fuel cell separator and method of production of same

The present invention releases a method of producing a metal separator for a solid polymer fuel cell by stainless steel, titanium, or titanium alloy during which securing lower cost and mass producibility by using a material having a high workability to form a complicated shape by a high productivity, then using an inexpensive blast process to drive a conductive substance into the surface of the metal separator member, that is, provides a stainless steel, titanium, or titanium alloy solid polymer fuel cell separator comprised of stainless steel, titanium, or titanium alloy in the surface of which a low ion release conductive substance is buried, having an arithmetic mean roughness (Ra) of the separator surface of 0.5 to 5.0 &#x3bc;m, having a 10-point mean roughness (Rz) of 3 to 20 &#x3bc;m, having an average spacing of surface relief shapes (Sm) of 300 &#x3bc;m or less, having values of a warp rate and twist rate of a separator of 0.1 or less, and having a contact resistance value with respect to carbon paper of 15 m&#x3a9;cmor less at a surface pressure of 1 MPa.

Stainless steel, titanium, or titanium alloy solid polymer fuel cell separator and its method of production and method of evaluation of warp and twist of separator

The present invention provides a separator for a solid polymer type fuel cell superior in low contact resistance of the fuel cell separator surface with carbon paper and flatness and a method of production of the same, that is, a separator for a solid polymer type fuel cell comprising a substrate of stainless steel or titanium or a titanium alloy having a surface layer part on which conductive compound particles are fixed, wherein said conductive compound particles are comprised of one or more types of metal borides, metal carbides, and metal nitrides with an average particle size of 0.01 to 20 &#x3bc;m, said conductive compound particles are present in a region from said substrate surface to a depth of 10 &#x3bc;m, and a distribution of concentration of the metal element forming the conductive compound in said region satisfies relations between a concentration C of the metal element forming the conductive compound and a depth x from the substrate surface shown by equation &#x3c;1&#x3e; (C=A&#xb7;exp(&#x2212;x/t)+B) and equation &#x3c;2&#x3e; (10&#x2266;A&#x2266;90, &#x2212;4.0&#x2266;B&#x2266;1.0, 0.5&#x2266;t&#x2266;4.0).

An apparatus for measuring a flow rate of a powder when a powder is conveyed by using air as a carrier gas, which apparatus measures the flow rate based on the change of capacitance of the powder to be measured. The apparatus that can measure the flow rate of a powder with high accuracy by compensating for the effect of the thermal drift of the capacitance. It includes a protecting pipe for conveying a powder, a housing pipe having measuring electrodes, and a transducer for outputting an output of the measuring electrode to a display. It further includes an atmospheric temperature sensor and a carrier gas-temperature sensor. The sensoris directly fixed to the protecting pipeat a place that does not overlap the housing pipe, and includes a circuit for compensating for the output of the measuring electrode, which output is the capacitance determined based on a graph of a curve of the relationship between a capacitance and a flow rate, based on the difference between the output of the atmospheric temperature sensor and the output of the carrier-gas-temperature sensor.

Apparatus for measuring a flow rate of a powder

A method for depositing a metal having a high corrosion resistance and a low contact resistance against carbon to a separator for a fuel cell enabling provision of an inexpensive separator for a fuel cell by depositing a metal having a high corrosion resistance and a low contact resistance against carbon to the surface of a metal conveniently by simple equipment while using as a preform a metal such as stainless steel or aluminum as a material having a high productivity and low price and in addition capable of reducing the weight by making the sheet thickness thin, comprising projecting to a separator of a unit cell for forming the fuel cell a solid plating material comprised of core particles having a higher hardness than the separator and coated with a metal having a high corrosion resistance and a low contact resistance against carbon so as to compulsorily deposit the metal coated on this solid plating material to the separator.

Method for depositing metal having high corrosion resistance and low contact resistance against carbon on separator for fuel cell

Growing community of inventors

Kitanagoya, Japan

Wataru Hisada