An alloy material is provided that has a chemical composition consisting of, in mass %, C: 0.030% or less, Si: 0.01 to 1.0%, Mn: 0.01 to 2.0%, P: 0.030% or less, S: 0.0050% or less, Cr: 28.0 to 40.0%, Ni: 32.0 to 55.0%, sol. Al: 0.010 to 0.30%, N: more than 0.30% and not more than 0.000214×Ni.sup.2−0.03012×Ni+0.00215×Cr.sup.2−0.08567×Cr+1.927, O: 0.010% or less, Mo: 0 to 6.0%, W: 0 to 12.0%, Ca: 0 to 0.010%, Mg: 0 to 0.010%, V: 0 to 0.50%, Ti: 0 to 0.50%, Nb: 0 to 0.50%, Co: 0 to 2.0%, Cu: 0 to 2.0%, REM: 0 to 0.10%, and the balance: Fe and impurities, and in which Fn1=Mo+(½)W is 1.0 to 6.0, and a yield strength at a 0.2% proof stress is 1103 MPa or more.

A permanent magnet alloy according to the present disclosure contains Mn at a content not lower than 41% by atom and not higher than 53% by atom; Al at a content not lower than 46% by atom and not higher than 53% by atom; and Cu at a content not lower than 0.5% by atom and not higher than 10% by atom. The alloy contains a stable phase, having a tetragonal structure, at a ratio not lower than 50%.

A low thermal expansion alloy having a high rigidity and a low thermal expansion coefficient comprising, by mass %, C: 0.040% or less, Si: 0.25% or less, Mn: 0.15 to 0.50%, Cr: 8.50 to 10.0%, Ni: 0 to 5.00%, and Co: 43.0 to 56.0%, S: 0 to 0.050%, and Se: 0 to 0.050% and having a balance of Fe and unavoidable impurities, the contents of Ni, Co, and Mn represented by [Ni], [Co], and [Mn] satisfying 55.7≤2.2[Ni]+[Co]+1.7[Mn]≤56.7 and the structure being an austenite single phase.

A low thermal expansion alloy having a high rigidity and a low thermal expansion coefficient comprising, by mass %, C: 0.040% or less, Si: 0.25% or less, Mn: 0.15 to 0.50%, Cr: 8.50 to 10.0%, Ni: 0 to 5.00%, and Co: 43.0 to 56.0%, S: 0 to 0.050%, and Se: 0 to 0.050% and having a balance of Fe and unavoidable impurities, the contents of Ni, Co, and Mn represented by [Ni], [Co], and [Mn] satisfying 55.7≤2.2[Ni]+[Co]+1.7[Mn]≤56.7 and the structure being an austenite single phase.

Disclosed are a BCC dual phase refractory superalloy with high phase stability and a manufacturing method therefor, the alloy comprising one or more of Ti, Zr, and Hf as Group 4 transition metals, one or more of Na and Ta as Group 5 transition metals, and Al, and having a structure of a BCC phase, wherein the BCC phase is composed of a disordered BCC phase and an ordered BCC phase, and wherein the ordered BCC phase is formed by allowing Al, which is a BCC phase forming element, to be soluted in an area of the BCC phase where the contents of the Group 5 transition metals are more than those of the Group 4 transition metals, so that the present disclosure provides a BCC dual phase refractory superalloy with high phase stability, characterized in that when a BCC dual phase with the ordered BCC phase and the disordered BCC phase separated from each other is formed by aging, the aging condition is precisely controlled through the apex temperature (T.sub.c) of the BCC phase miscibility gap, expressed by (Equation 1) below.
T.sub.c(K)=881.4+331.7*x+546.7*y+893.0*x*z (provided that, 0≤x≤1, 0≤y≤0.2, 0≤x+y≤1, and 0≤z≤1)  (Equation 1)

Disclosed are a BCC dual phase refractory superalloy with high phase stability and a manufacturing method therefor, the alloy comprising one or more of Ti, Zr, and Hf as Group 4 transition metals, one or more of Na and Ta as Group 5 transition metals, and Al, and having a structure of a BCC phase, wherein the BCC phase is composed of a disordered BCC phase and an ordered BCC phase, and wherein the ordered BCC phase is formed by allowing Al, which is a BCC phase forming element, to be soluted in an area of the BCC phase where the contents of the Group 5 transition metals are more than those of the Group 4 transition metals, so that the present disclosure provides a BCC dual phase refractory superalloy with high phase stability, characterized in that when a BCC dual phase with the ordered BCC phase and the disordered BCC phase separated from each other is formed by aging, the aging condition is precisely controlled through the apex temperature (T.sub.c) of the BCC phase miscibility gap, expressed by (Equation 1) below.

T.sub.c(K)=881.4+331.7*x+546.7*y+893.0*x*z  (Equation 1)

(provided that, 0≤x≤1, 0≤y≤0.2, 0≤x+y≤1, and 0≤z≤1)

A high-entropy alloy having ultra-high strength and high hydrogen embrittlement resistance due to formation of a microstructure at a low strain may be produced without a severe plastic deformation. A method for producing the high-entropy alloy includes (a) annealing and homogenizing an initial alloy material at 1000 to 1200° C. for 1 to 24 hours; and (b) rolling the annealed and homogenized initial alloy material into a rod, at a cryogenic temperature of −100 to −200° C. while pressing the initial alloy material in multi-axial directions at a strain of 0.4 to 1.2, thereby to produce the high-entropy alloy having intersecting twins as a microstructure, and secondary fine twins formed in the intersecting twins, wherein the initial alloy material contains Co of 5 to 35%, Cr of 5 to 35%, Fe of 5 to 35%, Mn of 5 to 35%, and Ni of 5 to 35%, based on weight %.

A high-entropy alloy having ultra-high strength and high hydrogen embrittlement resistance due to formation of a microstructure at a low strain may be produced without a severe plastic deformation. A method for producing the high-entropy alloy includes (a) annealing and homogenizing an initial alloy material at 1000 to 1200° C. for 1 to 24 hours; and (b) rolling the annealed and homogenized initial alloy material into a rod, at a cryogenic temperature of −100 to −200° C. while pressing the initial alloy material in multi-axial directions at a strain of 0.4 to 1.2, thereby to produce the high-entropy alloy having intersecting twins as a microstructure, and secondary fine twins formed in the intersecting twins, wherein the initial alloy material contains Co of 5 to 35%, Cr of 5 to 35%, Fe of 5 to 35%, Mn of 5 to 35%, and Ni of 5 to 35%, based on weight %.

In the production of an internal-tin-processed Nb.sub.3Sn superconducting wire, the present invention provides a Nb.sub.3Sn superconducting wire that is abundant in functionality, such as, the promotion of formation of a Nb.sub.3Sn layer, the mechanical strength of the superconducting filament (and an increase in interface resistance), the higher critical temperature (magnetic field), and the grain size reduction, and a method for producing it. A method for producing a Nb.sub.3Sn superconducting wire according to an embodiment of the present invention includes a step of providing a bar 10 that has a Sn insertion hole 12 provided in a central portion of the bar 10 and a plurality of Nb insertion holes 14 provided discretely along an outer peripheral surface of the Sn insertion hole 12, and that has an alloy composition being Cu-xZn-yM (x: 0.1 to 40 mass %, M=Ge, Ga, Mg, or Al, provided that, for Mg, x: 0 to 40 mass %), a step of mounting an alloy bar with an alloy composition of Sn-zQ (Q=Ti, Zr, or Hf) into the Sn insertion hole 12 and inserting Nb cores into the Nb insertion holes 14, a step of subjecting the bar 10 to diameter reduction processing to fabricate a Cu-xZn-yM/Nb/Sn-zQ composite multicore wire with a prescribed outer diameter, and a step of subjecting the composite multicore wire to Nb.sub.3Sn phase generation heat treatment.

In the production of an internal-tin-processed Nb.sub.3Sn superconducting wire, the present invention provides a Nb.sub.3Sn superconducting wire that is abundant in functionality, such as, the promotion of formation of a Nb.sub.3Sn layer, the mechanical strength of the superconducting filament (and an increase in interface resistance), the higher critical temperature (magnetic field), and the grain size reduction, and a method for producing it. A method for producing a Nb.sub.3Sn superconducting wire according to an embodiment of the present invention includes a step of providing a bar 10 that has a Sn insertion hole 12 provided in a central portion of the bar 10 and a plurality of Nb insertion holes 14 provided discretely along an outer peripheral surface of the Sn insertion hole 12, and that has an alloy composition being Cu-xZn-yM (x: 0.1 to 40 mass %, M=Ge, Ga, Mg, or Al, provided that, for Mg, x: 0 to 40 mass %), a step of mounting an alloy bar with an alloy composition of Sn-zQ (Q=Ti, Zr, or Hf) into the Sn insertion hole 12 and inserting Nb cores into the Nb insertion holes 14, a step of subjecting the bar 10 to diameter reduction processing to fabricate a Cu-xZn-yM/Nb/Sn-zQ composite multicore wire with a prescribed outer diameter, and a step of subjecting the composite multicore wire to Nb.sub.3Sn phase generation heat treatment.