A method for manufacturing a Cu—Ni—Al-based sintered alloy according to the present invention includes: adding pure Al powder to alloy powder containing Cu, Ni, and Al and mixing them to produce raw material powder with a composition ratio of Ni: 1% to 15% by mass, Al: 1.9% to 12% by mass, and a Cu balance containing inevitable impurities; compacting the raw material powder to form a green compact; and sintering the green compact in a mixture gas atmosphere of hydrogen gas and nitrogen gas that contains 3% by volume or more of hydrogen gas.

A method for manufacturing a Cu—Ni—Al-based sintered alloy according to the present invention includes: adding pure Al powder to alloy powder containing Cu, Ni, and Al and mixing them to produce raw material powder with a composition ratio of Ni: 1% to 15% by mass, Al: 1.9% to 12% by mass, and a Cu balance containing inevitable impurities; compacting the raw material powder to form a green compact; and sintering the green compact in a mixture gas atmosphere of hydrogen gas and nitrogen gas that contains 3% by volume or more of hydrogen gas.

Fuel cell alloy bipolar plates. The alloys may be used as a coating or bulk material. The alloys and metallic glasses may be particularly suitable for proton-exchange membrane fuel cells because of they may exhibit reduced weights and/or better corrosion resistance. The alloys may include any of the following Al.sub.xCu.sub.yTi.sub.z, Al.sub.xFe.sub.yNi.sub.z, Al.sub.xMn.sub.yNi.sub.z, Al.sub.xNi.sub.yTi.sub.z, Cu.sub.xFe.sub.yTi.sub.z, Cu.sub.xNi.sub.yTi.sub.z, Al.sub.xFe.sub.ySi.sub.z, Al.sub.xMn.sub.ySi.sub.z, Al.sub.xNi.sub.ySi.sub.z, Ni.sub.xSi.sub.yTi.sub.z, and C.sub.xFe.sub.ySi.sub.z. The alloys or metallic glass may be doped with various dopants to improve glass forming ability, mechanical strength, ductility, electrical or thermal conductivities, hydrophobicity, and/or corrosion resistance.

Fuel cell alloy bipolar plates. The alloys may be used as a coating or bulk material. The alloys and metallic glasses may be particularly suitable for proton-exchange membrane fuel cells because of they may exhibit reduced weights and/or better corrosion resistance. The alloys may include any of the following Al.sub.xCu.sub.yTi.sub.z, Al.sub.xFe.sub.yNi.sub.z, Al.sub.xMn.sub.yNi.sub.z, Al.sub.xNi.sub.yTi.sub.z, Cu.sub.xFe.sub.yTi.sub.z, Cu.sub.xNi.sub.yTi.sub.z, Al.sub.xFe.sub.ySi.sub.z, Al.sub.xMn.sub.ySi.sub.z, Al.sub.xNi.sub.ySi.sub.z, Ni.sub.xSi.sub.yTi.sub.z, and C.sub.xFe.sub.ySi.sub.z. The alloys or metallic glass may be doped with various dopants to improve glass forming ability, mechanical strength, ductility, electrical or thermal conductivities, hydrophobicity, and/or corrosion resistance.

A system to attach valve seat inserts to an aluminum cylinder head of an automobile vehicle includes a cylinder head of an automobile vehicle engine having a valve seat portion. A valve seat insert is positioned in the valve seat portion of the cylinder head. A fusion bond is created between the valve seat insert and the valve seat portion by laser welding thereby fusing the valve seat insert to the valve seat portion.

A system to attach valve seat inserts to an aluminum cylinder head of an automobile vehicle includes a cylinder head of an automobile vehicle engine having a valve seat portion. A valve seat insert is positioned in the valve seat portion of the cylinder head. A fusion bond is created between the valve seat insert and the valve seat portion by laser welding thereby fusing the valve seat insert to the valve seat portion.

A sintered bearing 1 is formed by sintering a raw material powder containing aluminum fluoride. The sintered bearing 1 has a structure obtained by sintering an aluminum-copper alloy and contains 3 to 13 mass % aluminum and 0.05 to 0.6 mass % phosphorus, copper as a main component of the remainder, and inevitable impurities. The sintered bearing 1 is manufactured by performing sintering in a closed space 23, and by, under the assumption that all aluminum fluoride contained in the raw material powder is gasified in the closed space 23, controlling the concentration of the aluminum fluoride gas to be 5 ppm or more, thus performing the sintering.

Fuel cell alloy bipolar plates. The alloys may be used as a coating or bulk material. The alloys and metallic glasses may be particularly suitable for proton-exchange membrane fuel cells because of they may exhibit reduced weights and/or better corrosion resistance. The alloys may include any of the following Al.sub.xCu.sub.yTi.sub.z, Al.sub.xFe.sub.yNi.sub.z, Al.sub.xMn.sub.yNi.sub.z, Al.sub.xNi.sub.yTi.sub.z, Cu.sub.xFe.sub.yTi.sub.z, Cu.sub.xNi.sub.yTi.sub.z, Al.sub.xFe.sub.ySi.sub.z, Al.sub.xMn.sub.ySi.sub.z, Al.sub.xNi.sub.ySi.sub.z, Ni.sub.xSi.sub.yTi.sub.z, and C.sub.xFe.sub.ySi.sub.z. The alloys or metallic glass may be doped with various dopants to improve glass forming ability, mechanical strength, ductility, electrical or thermal conductivities, hydrophobicity, and/or corrosion resistance.

The present invention discloses a Nb and Al-containing titanium-copper alloy strip, characterized in that the weight percentage composition of the titanium-copper alloy strip comprises: 2.00-4.50 wt % Ti, 0.005-0.4 wt % Nb, and 0.01-0.5 wt % Al, balance being Cu and unavoidable impurities. Preferably, in the microstructure of the titanium-copper alloy strip, the number of Nb and Al-containing intermetallic compound particles with a particle size of 50-500 nm is not less than 1×10.sup.5/mm.sup.2, and the number of Nb and Al-containing intermetallic compound particles with a particle size greater than 1 μm is not more than 1×10.sup.3/mm.sup.2. Under the condition of ensuring excellent bendability, the titanium-copper alloy strip has excellent stability, especially the stability of mechanical properties at high temperatures. The present invention also relates to a method for producing the titanium-copper alloy strip.

The present invention discloses a Nb and Al-containing titanium-copper alloy strip, characterized in that the weight percentage composition of the titanium-copper alloy strip comprises: 2.00-4.50 wt % Ti, 0.005-0.4 wt % Nb, and 0.01-0.5 wt % Al, balance being Cu and unavoidable impurities. Preferably, in the microstructure of the titanium-copper alloy strip, the number of Nb and Al-containing intermetallic compound particles with a particle size of 50-500 nm is not less than 1×10.sup.5/mm.sup.2, and the number of Nb and Al-containing intermetallic compound particles with a particle size greater than 1 μm is not more than 1×10.sup.3/mm.sup.2. Under the condition of ensuring excellent bendability, the titanium-copper alloy strip has excellent stability, especially the stability of mechanical properties at high temperatures. The present invention also relates to a method for producing the titanium-copper alloy strip.