Abstract: A Co-base alloy which has a basic composition including, in terms of mass proportion, 0.1%-10% Al, 3.0-45% W, and Co as the remainder and has an intermetallic compound of the Ll2 type [Co3(Al,W)] dispersed and precipitated therein. Part of the Co may be replaced with Ni, Ir, Fe, Cr, Re, or Ru, while part of the Al and W may be replaced with Ni, Ti, Nb, Zr, V, Ta or Hf. The intermetallic compound [Co3(Al, W)] has a high melting point, and this compound and the matrix are mismatched little with respect to lattice constant. Thus, the cobalt-base alloy can have high-temperature strength equal to that of nickel-base alloys and excellent structure stability.

Abstract: A shape memory alloy comprises Co, Ni and Al with a two-phase structure comprising a ?-phase having a B2 structure and a ?-phase having an fcc structure, at least 40% by area of crystal grain boundaries of the ?-phase being occupied by the ?-phase. The shape memory alloy can be produced by a first heat treatment step comprising heating at 1200 to 1350° C. for 0.1 to 50 hours and cooling at 0.1 to 1000° C./minute, and a second heat treatment step comprising heating at 1000 to 1320° C. for 0.1 to 50 hours and cooling at 10 to 10000° C./minute.

Abstract: A member having a separated structure made by an alloy consisting of two regions having different compositions with each other is formed by casting a molten alloy into a prescribed shape, or by spray-quenching the same from a temperature of Tc+10° C. or more, wherein the molten alloy exhibits two phase separation in a liquid state having a temperature difference ?T between the maximum temperature Tc (° C.) and minimum temperature Td (° C.) in the region of two phase separation in the liquid state being 10° C. or more, and the molten alloy has a mean composition with a difference of the volume fraction between the two liquid phases of 5% by volume or more. The suitable alloy is a Cu—Fe—X alloy, a Cu—Cr—X alloy, a Cu—Co—X alloy, a Cu—Bi—X alloy, an Al—Sn—X alloy or an Al—In—X alloy.

Abstract: A thermoelectric module comprises a plurality of thermoelectric elements which are arranged between a pair of substrates having electrode patterns and which are bonded with the electrode patterns via solder in which at least one dispersion phase is dispersed into a matrix phase, wherein the melting temperature of the dispersion phase is higher than that of the matrix phase (i.e., 240° C. or over), and the dispersion phase comprises fine particles whose average diameter is 5 ?m or less. The solder is constituted by an alloy so as to realize a volume ratio of 40% or less, wherein it is composed of a Bi—Cu—X alloy or a Bi—Zn—X alloy (where ‘X’ represents at least one element selected in advance). Preferably, the solder is constituted by powder containing fine particles whose average diameter is 100 ?m or less or thin plates whose average thickness is 500 ?m or less.

Abstract: Guide wires and catheters made from a functionally graded alloy comprising 3-10 weight % Al and 5-20 weight % Mn, the balance being substantially Cu and inevitable impurities. The functionally graded alloy is produced by forming the copper-based alloy, maintaining it at a temperature of at least 500° C. and rapidly cooling it, and then subjecting the alloy to an aging treatment by a gradient temperature heater.

Abstract: A shape memory alloy comprises Co, Ni and Al with a two-phase structure comprising a ?-phase having a B2 structure and a ?-phase having an fcc structure, at least 40% by area of crystal grain boundaries of the ?-phase being occupied by the ?-phase. The shape memory alloy can be produced by a first heat treatment step comprising heating at 1200 to 1350° C. for 0.1 to 50 hours and cooling at 0.1 to 1000° C./minute, and a second heat treatment step comprising heating at 1000 to 1320° C. for 0.1 to 50 hours and cooling at 10 to 10000° C./minute.

Abstract: A copper alloy having superior thermal conductivity comparable to that of conventional materials, can be produced at low cost. An oxygen free copper, a base material of a Cu—B alloy were melted in vacuo by a casting method, B and at least one element selected from Mg, Ni, Co, Al, Si, Fe, Zr, and Mn are added into the molten metal wherein the content of each element or the alloy of Ni—B, Fe—B, Cu—Mg, and so forth becoming the predetermined content. This alloy is cast into an ingot of 12 mm square, heated at 600 to 900° C. for 1 hour, and the cast was rolled to be 3 mm by hot rolling. After these steps, heat treatment at 600 to 900° C. was provided and processed into predetermined shape.

Abstract: A member having a separated structure made by an alloy consisting of two regions having different compositions with each other is formed by casting a molten alloy into a prescribed shape, or by spray-quenching the same from a temperature of Tc+10° C. or more, wherein the molten alloy exhibits two phase separation in a liquid state having a temperature difference &Dgr;T between the maximum temperature Tc (° C.) and minimum temperature Td (° C.) in the region of two phase separation in the liquid state being 10° C. or more, and the molten alloy has a mean composition with a difference of the volume fraction between the two liquid phases of 5% by volume or more. The suitable alloy is a Cu—Fe—X alloy, a Cu—Cr—X alloy, a Cu—Co—X alloy, a Cu—Bi—X alloy, an Al—Sn—X alloy or an Al—In—X alloy.

Abstract: The present invention provides a copper-based alloy having high shape memory properties and superelasticity while maintaining an excellent workability, members such as a wire, plate, pipe, etc. made of the copper-based alloy, and methods for producing them. The copper-based alloy has a recrystallization structure substantially composed of &bgr;-single phase, and can be produced by a method comprising the steps of: forming an alloy by cold-working with a particular maximum cold-working ratio; and subjecting the cold-worked alloy to at least one solution treatment for improving a crystal orientation of the &bgr;-single phase, a quenching and an aging treatment. The maximum cold-working ratio is set so that the crystal orientation density of the &bgr;-single phase measured by an electron back scattering pattern method is 2.0 or more in a cold-working direction.

Abstract: Guide wires and catheters made from a functionally graded alloy comprising 3-10 weight % Al and 5-20 weight % Mn, the balance being substantially Cu and inevitable impurities. The functionally graded alloy is produced by forming the copper-based alloy, maintaining it at a temperature of at least 500° C. and rapidly cooling it, and then subjecting the alloy to an aging treatment by a gradient temperature heater.

Abstract: The functionally graded alloy having a composition comprising 3-10 weight % of Al, 5-20 weight % of Mn, the balance being substantially Cu and inevitable impurities has a first portion composed essentially of a &bgr;-phase, a second portion composed essentially of an &agr;-phase and a Heusler phase, and a third portion having a crystal structure changing continuously or stepwise from the first portion to the second portion. The functionally graded alloy can be produced by forming a copper-based alloy having the above composition, keeping it at 500° C. or higher and rapidly cooling it, and then subjecting it to an aging treatment by a gradient temperature heater. Such functionally graded alloy can suitably be used for guide wires and catheters.