摘要:
A method for manufacturing a fuel cell separator, including: forming by a PVD method a precious metal layer on a surface of a substrate, as a fuel cell separator, made of Ti or a Ti alloy, wherein the precious metal layer includes at least one precious metal selected from Ru, Rh, Pd, Os, Ir, Pt and Au and has a thickness of 2 nm or more, and a heat treatment wherein the substrate on which the precious metal layer was formed in the precious metal layer forming is subjected to a heat treatment at a predetermined heat treatment temperature and under a predetermined oxygen partial pressure. According to the method, a fuel cell separator made of Ti or a Ti alloy having excellent corrosion resistance, good adhesion of a precious metal layer, low contact resistance, and further excellent productivity can be produced.
摘要:
A titanium material for an electrode comprising a titanium alloy substrate containing at least one noble metal element selected from platinum group elements, Au and Ag; and a layer of a mixture formed on the titanium alloy substrate, said mixture comprising the noble metal element precipitated from the titanium alloy substrate and titanium oxide, and said layer having an average thickness of up to 200 nm; wherein the mixture layer on the surface and the titanium alloy substrate have a conductivity in terms of contact resistance as determined by the following method of up to 12 mΩ·cm2. The contact resistance is determined by placing a carbon cloth having an average thickness of 0.3 mm on opposite surfaces of the titanium alloy substrate having the mixture layer formed thereon; sandwiching the titanium alloy material with a pair of copper electrodes via the carbon cloth, the copper electrodes each having a contact area with the titanium alloy material of 1 cm2; measuring voltage drop between the carbon cloths by using a four terminal ohmmeter while pressing the copper electrodes against the titanium alloy material at a surface pressure of 5 kg/cm2 by using a hydraulic press and applying an electric current of 7.4 mA between the copper electrodes; and calculating the contact resistance from the measured value.
摘要:
A separator for a fuel cell comprising a titanium alloy substrate containing at least one noble metal element selected from platinum group elements, Au and Ag; and a layer of a mixture formed on the titanium alloy substrate, said mixture comprising the noble metal element precipitated from the titanium alloy substrate and titanium oxide, and said layer having an average thickness of up to 200 nm; wherein the mixture layer on the surface and the titanium alloy substrate have a conductivity in terms of contact resistance as determined by the following method of up to 12 mΩ·cm2. The contact resistance is determined by placing a carbon cloth having an average thickness of 0.3 mm on opposite surfaces of the titanium alloy substrate having the mixture layer formed thereon; sandwiching the titanium alloy material with a pair of copper electrodes via the carbon cloth, the copper electrodes each having a contact area with the titanium alloy material of 1 cm2; measuring voltage drop between the carbon cloths by using a four terminal ohmmeter while pressing the copper electrodes against the titanium alloy material at a surface pressure of 5 kg/cm2 by using a hydraulic press and applying an electric current of 7.4 mA between the copper electrodes; and calculating the contact resistance from the measured value.
摘要:
A titanium material of the present invention includes a base material composed of a titanium alloy containing at least one alloying element selected from the group consisting of gold, silver, and platinum group elements; and a concentrated layer integrally disposed as a layer on the surface of the base material. In the concentrated layer, the alloying elements are concentrated by elution of Ti from the surface of the base material. The average thickness of the concentrated layer is 2.5 nm or more. The total alloying element concentration in the concentrated layer is 40 to 100 atomic percent. The total content of the alloying element in the base material is 0.01 to 1.0 percent by mass. Electrodes composed of the titanium material of the present invention are suitable for use in separators of fuel cells, and can readily be produced, so that the cost can be reduced.
摘要:
Disclosed herein is a surface treatment method of a titanium material for electrodes characterized by including: a titanium oxide layer formation step S1 of forming a titanium oxide layer with a thickness of 10 nm or more and 80 nm or less on the surface of a titanium material including pure titanium or a titanium alloy; a noble metal layer formation step S2 of forming a noble metal layer with a thickness of 2 nm or more including at least one noble metal selected from Au, Pt, and Pd on the titanium oxide layer by a PVD method; and a heat treatment step S3 of heat treating the titanium material having the noble metal layer formed thereon at a temperature of 300° C. or more and 800° C. or less.
摘要:
A titanium substrate, for forming a separator for a fuel cell, is made of titanium or a titanium alloy and has surface layers containing carbon having binding energy in the range of to 284 eV as measured by x-ray photoelectron spectroscopy in a carbon content of 25% at. or below.
摘要:
A titanium alloy material includes a Ti—Al alloy and an oxide film on the Ti—Al alloy. The Ti—Al alloy contains 0.50-3.0 mass % Al and a balance of Ti and unavoidable impurities. The titanium alloy material has excellent hydrogen absorption resistance and can be used as a basic structural material in hydrogen absorption environments.
摘要:
The present invention provides a titanium material having high-temperature oxidation resistance at high temperatures above 800° C. and an exhaust pipe made of this titanium material for an engine. A titanium alloy contains 0.15 to 2% by mass Si, has an Al content below 0.30% by mass, and has equiaxial structure having a mean grain size of 15 μm or above. The high-temperature oxidation resistance of the titanium alloy at high temperatures above 800° C., such as 850° C., is improved by means including adding Nb, Mo and Cr in combination with Si to the titanium alloy, forming equiaxial structure of coarse grains, creating acicular structure, Si-enrichment of a surface layer of the titanium alloy, and reducing impurities including copper, oxygen and carbon contained in the titanium alloy.
摘要:
A titanium alloy having excellent high-temperature oxidation and corrosion resistance is disclosed which comprises, by mass, Al: 0.30–1.50%, and Si: 0.10–1.0%. Preferably, amass ratio Si/Al is not less than 1/3. More preferably, the titanium alloy further comprises Nb: 0.1–0.5% by mass. The titanium alloy is useful as an exhaust system material for a vehicle or a motorbike, which enhances corrosion and high-temperature oxidation resistance, while utilizing inherent lightness and corrosion resistance of an original titanium alloy without impairing economy and workability.
摘要:
A corrosion resistant Ti based alloy comprising:Cr: 0.005-2.0 wt %, and further comprising one or more of elements selected from:Ni: 0.005-2.0 wt %, Pd: 0.005-2.0 wt %, Ru: 0.005-2.0 wt %, Pt: 0.005-2.0 wt %, Os: 0.005-2.0 wt %, Ir: 0.005-2.0 wt %, Rh: 0.005-2.0 wt %, andthe balance of Ti and inevitable impurities.Cr may be replaced with one or more of 0.005-1.5 wt % of Cu and 0.005-1.5 wt % of Si, or 0.005-2.0 wt % of Al. The corrosion resistant Ti based alloy has excellent corrosion resistance also in a non-oxidative atmosphere and also has an excellent crevice corrosion resistance.