ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Melt-quenched Cu-Nb-(Ti, Zr, Hf) ternary alloys have been found to be amorphous possessing high strength and good bend ductility. The niobium content in the amorphous alloys was limited to less than 35 at % and the titanium, zirconium or hafnium contents from 25 to 50 at %. The Cu40Nb30(Ti, Hf)30 alloys showed a superconducting transition above the liquid helium temperature (4.2 K) after annealing at appropriate temperatures. The highest transition temperatures attained were 5.6 K for the Cu40Nb30Ti30 alloy annealed for 1 h at 873 K and 8.4 K for the Cu40Nb30Hf30 alloy annealed for 1 h at 1073 K. In addition, these alloys exhibited upper critical magnetic fields of 1.8 to 2.3×106 Am−1 at 4.2 K and critical current densities of 2×103 to 1×104 A cm−2 at zero applied field and 4.2 K. Since the structure of the superconducting samples consisted of ordered phases based on a b c c lattice with a lattice parameter of 0.31 nm, it was concluded that the superconductivity in the Cu40Nb30Ti30 and Cu40Nb30Hf30 alloys was due to the precipitation of the metastable ordered b c c phases.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01033856
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