Abstract: 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 ?m 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.

Abstract: 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 m?·cm2. The contact resistance is determined by placing a carbon cloth having an average thickness of 0.

Abstract: A titanium alloy contains Ni in a content of 0.35% to 0.55%; Pd in a content of 0.01% to 0.02%; Ru in a content of 0.02% to 0.04%; and Cr in a content of 0.1% to 0.2%, with the remainder including titanium and inevitable impurities, in which the titanium alloy includes nickel-rich phases, each nickel-rich phase being a phase (other than titanium alpha phase) locally containing Ni in a content of 10 times or more the average Ni content of the titanium alloy, the nickel-rich phases are aligned along a rolling direction to form a row, and a multiplicity of the rows are aligned substantially in parallel in a cross direction. The titanium alloy minimizes the proceeding of intergranular corrosion even in specific environments where the intergranular corrosion may easily proceed.

Abstract: 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.

Abstract: 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 ?m 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.

Abstract: 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.

Abstract: 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 m?·cm2. The contact resistance is determined by placing a carbon cloth having an average thickness of 0.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: (1) A titanium material composed of a substrate of pure titanium or titanium alloy and an aluminum-containing layer formed thereon having a thickness no smaller than 1 ?m and containing no less than 90 mass % aluminum or aluminum plus silicon. (2) A titanium material composed of a substrate of pure titanium or titanium alloy and an aluminum-containing layer formed thereon having a thickness no smaller than 1 ?m and containing no less than 90 mass % aluminum or aluminum plus silicon, with a layer of Al—Ti intermetallic compound interposed between them. (3) A titanium material as defined in (1) wherein the substrate contains 0.5-10 mass % aluminum. (4) A titanium material as defined in (1) wherein that surface of the substrate with which the aluminum-containing layer is in contact contains 20-50 atomic % nitrogen. (5) A titanium material as defined in (1) wherein a layer of aluminum nitride is formed in the interface between the substrate and the aluminum-containing layer.

Abstract: 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.

Abstract: Disclosed are a surface-treated titanium material that is excellent in oxidation resistance and allows the excellent oxidation resistance to last for a long period of time and the surface treatment itself to be applied safely at a low cost; the production method thereof; and an exhaust system thereof. A surface-treated titanium material produced by forming an oxidation-resistant baked film 5 ?m or more in thickness on a substrate comprising commercially pure titanium or titanium-base alloy, and said baked film is formed by filling the gaps among particles comprising Al alloy containing Si by 10 at % or less or commercially pure aluminum with chemical compounds comprising a metallic element M (M represents one or more of Ti, Zr, Cr, Si and Al) and C and/or O.

Abstract: A titanium alloy scarcely undergoing brittling caused by hydrogen even in case of being used under hydrogen-absorbing conditions. This alloy comprises a Ti—Al alloy composed of from 0.50 to 3.0% of Al with the balance of Ti together with unavoidable contaminants. A Ti—Al alloy material excellent in hydrogen absorption-resistance wherein an oxidized film of 1.0 to 100 nm in thickness is formed on a bulk made of a Ti—Al alloy satisfying the chemical composition as described above, and, further, a concentrated Al layer having an Al concentration of 0.8 to 25% higher by 0.3% or more than the bulk is optionally formed between the bulk and the oxidized film.

Abstract: 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 ?. 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.

Abstract: (1) A titanium material composed of a substrate of pure titanium or titanium alloy and an aluminum-containing layer formed thereon having a thickness no smaller than 1 &mgr;m and containing no less than 90 mass % aluminum or aluminum plus silicon. (2) A titanium material composed of a substrate of pure titanium or titanium alloy and an aluminum-containing layer formed thereon having a thickness no smaller than 1 &mgr;m and containing no less than 90 mass % aluminum or aluminum plus silicon, with a layer of Al—Ti intermetallic compound interposed between them. (3) A titanium material as defined in (1) wherein the substrate contains 0.5-10 mass % aluminum. (4) A titanium material as defined in (1) wherein that surface of the substrate with which the aluminum-containing layer is in contact contains 20-50 atomic % nitrogen. (5) A titanium material as defined in (1) wherein a layer of aluminum nitride is formed in the interface between the substrate and the aluminum-containing layer.

Abstract: A pure titanium building material having high secular discoloration resistance is formed of pure titanium having an Fe content of 0.08% by mass or below, a Nb content of 0.02% by mass or below, and a Co content of 0.02% by mass or below.

Abstract: A muffler of a muffler made of a titanium alloy wherein advantages of lightness and corrosion-resistance that the titanium alloy originally has are used, and heat-resistance and oxidization-resistance are heightened without damaging costs or workability so that the span of life and flexibility for design are improved. A muffler made of a titanium alloy, wherein the titanium alloy comprises 0.5-2.3% by mass of Al and optionally one or more other alloying elements. The metal texture may comprise more than 90% by volume of the &agr; phase and 20% or less of the &bgr; phase. This muffler is superior in heat-resistance, oxidization-resistance, weldability and so on.

Abstract: A muffler of a muffler made of a titanium alloy wherein advantages of lightness and corrosion-resistance that the titanium alloy originally has are used, and heat-resistance and oxidization-resistance are heightened without damaging costs or workability so that the span of life and flexibility for design are improved. A muffler made of a titanium alloy, wherein the titanium alloy comprises 0.5-2.3% by mass of Al and optionally one or more other alloying elements. The metal texture may comprise more than 90% by volume of the &agr; phase and 20% or less of the &bgr; phase. This muffler is superior in heat-resistance, oxidization-resistance, weldability and so on.

Abstract: A corrosion-resistant Ti alloy includes Pd in an amount of 0.020-0.050 mass %, and includes one or more platinum group elements other than Pd in an amount of one-third or more of the mass of Pd, with the balance being composed of allowable components and Ti. This alloy exhibits excellent corrosion-resistance. If the Fe content is 0.05% or less and O content is 0.05% or less, excellent cold-workability can be obtained. If the Pd content is 0.030% or less, not only cold-workability and corrosion-resistance but also resistance against hydrogen absorption can be obtained.