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.

A multiple-element composite material for negative electrodes, a preparation method therefor, and a lithium-ion battery using the negative electrode material. The lithium-ion battery uses multiple-element composite material for negative electrodes has a core-shell structure containing multiple shell layers. The inner core consists of graphite and nano-active matter coating the surface of the graphite. The outer layers of the inner core are in order: the first shell layer is of an electrically conductive carbon material, the second shell layer is of a nano-active matter, and the third shell layer is an electrically conductive carbon material coating layer. The multiple-element composite material for negative electrodes of the present invention combines coating processing technology with surface composite modification and coating modification technology to successfully prepare a multiple-element composite material for negative electrodes having a core-shell structure containing multiple shell layers, and allows for high load and high dispersion for the nano-active matter, thereby substantially enhancing the material specific capacity, cycle performance, and initial efficiency. Additionally, the multiple-element composite material for negative electrodes of the present invention has high compacted density and good processing performance. The negative electrode material has simple preparation technique and low raw material cost, is environmentally friendly, and causes no pollution.

A multiple-element composite material for negative electrodes, a preparation method therefor, and a lithium-ion battery using the negative electrode material. The lithium-ion battery uses multiple-element composite material for negative electrodes has a core-shell structure containing multiple shell layers. The inner core consists of graphite and nano-active matter coating the surface of the graphite. The outer layers of the inner core are in order: the first shell layer is of an electrically conductive carbon material, the second shell layer is of a nano-active matter, and the third shell layer is an electrically conductive carbon material coating layer. The multiple-element composite material for negative electrodes of the present invention combines coating processing technology with surface composite modification and coating modification technology to successfully prepare a multiple-element composite material for negative electrodes having a core-shell structure containing multiple shell layers, and allows for high load and high dispersion for the nano-active matter, thereby substantially enhancing the material specific capacity, cycle performance, and initial efficiency. Additionally, the multiple-element composite material for negative electrodes of the present invention has high compacted density and good processing performance. The negative electrode material has simple preparation technique and low raw material cost, is environmentally friendly, and causes no pollution.

The invention relates to a substantially equiatomic FeCo-alloy cold-rolled strip or sheet, and to a magnetic part cut from same, as well as to a method for fabricating a FeCo-alloy cold-rolled strip or sheet. A fully recrystallized hot-rolled sheet or strip is prepared, with a thickness of 1.5-2.5 mm and the following composition: 47.0%Co51.0%; tracesV+W3.0%; tracesTa+Zr0.5%; tracesNb0.5%; tracesB0.05%; tracesSi3.0%; tracesCr3.0%; tracesNi5.0%; tracesMn2.0%; tracesO0.03%; tracesN0.03%; tracesS0.005%; tracesP0.015; tracesMo0.3%; tracesCu0.5%; tracesAl0.01%; tracesTi0.01%; tracesCa+Mg0.05%; tracesrare earths500 ppm; the remainder being iron and impurities. A first cold-rolling step is carried out with a reduction rate of 70 to 90%, to bring the strip or sheet to a thickness of 1 mm. Intermediate annealing is carried out when running, leading to a partial recrystallization of the strip or sheet, running at a speed (V), and where its temperature, in the useful zone of the furnace of useful length (Lu), is between Trc and 900 C., the strip or sheet remaining therein for 15 s to 5 min at a temperature (T) such that 26 C..Math.minTTrc).Math.Lu/V160 C. min. The strip or sheet is cooled to at least 600 C./hour. A second step of cold-rolling the annealed strip or sheet is carried out, with a reduction rate of 60 to 80%, to bring the strip or sheet to a thickness of 0.05 to 0.25 mm. And final annealing (Rf) of the cold-rolled strip or sheet is carried out to achieve complete recrystallization followed by cooling at 100 to 500 C./hour.

Magnetic part, such as a magnetic core, obtained from a strip or sheet manufactured by this method.

The invention relates to a substantially equiatomic FeCo-alloy cold-rolled strip or sheet, and to a magnetic part cut from same, as well as to a method for fabricating a FeCo-alloy cold-rolled strip or sheet. A fully recrystallized hot-rolled sheet or strip is prepared, with a thickness of 1.5-2.5 mm and the following composition: 47.0%Co51.0%; tracesV+W3.0%; tracesTa+Zr0.5%; tracesNb0.5%; tracesB0.05%; tracesSi3.0%; tracesCr3.0%; tracesNi5.0%; tracesMn2.0%; tracesO0.03%; tracesN0.03%; tracesS0.005%; tracesP0.015; tracesMo0.3%; tracesCu0.5%; tracesAl0.01%; tracesTi0.01%; tracesCa+Mg0.05%; tracesrare earths500 ppm; the remainder being iron and impurities. A first cold-rolling step is carried out with a reduction rate of 70 to 90%, to bring the strip or sheet to a thickness of 1 mm. Intermediate annealing is carried out when running, leading to a partial recrystallization of the strip or sheet, running at a speed (V), and where its temperature, in the useful zone of the furnace of useful length (Lu), is between Trc and 900 C., the strip or sheet remaining therein for 15 s to 5 min at a temperature (T) such that 26 C..Math.minTTrc).Math.Lu/V160 C. min. The strip or sheet is cooled to at least 600 C./hour. A second step of cold-rolling the annealed strip or sheet is carried out, with a reduction rate of 60 to 80%, to bring the strip or sheet to a thickness of 0.05 to 0.25 mm. And final annealing (Rf) of the cold-rolled strip or sheet is carried out to achieve complete recrystallization followed by cooling at 100 to 500 C./hour.

Magnetic part, such as a magnetic core, obtained from a strip or sheet manufactured by this method.

A lead-free solder alloy composition includes a lead-free solder alloy; and a flower-shaped metal nano-particle including a metal core and protrusion portions extending from a surface of the metal core, wherein the metal core and the protrusion portions of the metal nano-particle include only one metal element.

A lead-free solder alloy composition includes a lead-free solder alloy; and a flower-shaped metal nano-particle including a metal core and protrusion portions extending from a surface of the metal core, wherein the metal core and the protrusion portions of the metal nano-particle include only one metal element.

A high-entropy austenitic stainless steel and a preparation method thereof are provided. The elemental composition of the stainless steels developed by the invention is as follows: Cr: 5-30%; Ni: 5-50%; Ti: 1-15%; Al: 1-15%; the rest are Fe and inevitable impurities; preferably, the composition is Cr: 5-19%; Ni: 5-29%; Ti: 6-15%; Al: 5-15%; the rest element is Fe. By adjusting the atomic ratio of each element, the nano-sized precipitates are generated as much as possible, and the strength is maximized while maintaining a high plasticity. The stainless steels provided by this invention have only five alloying components, a low manufacturing cost, and high-strength and high-plasticity. They can be widely used in many industrial fields such as aviation, aerospace, marine, and nuclear power with broad market prospects.

A high-entropy austenitic stainless steel and a preparation method thereof are provided. The elemental composition of the stainless steels developed by the invention is as follows: Cr: 5-30%; Ni: 5-50%; Ti: 1-15%; Al: 1-15%; the rest are Fe and inevitable impurities; preferably, the composition is Cr: 5-19%; Ni: 5-29%; Ti: 6-15%; Al: 5-15%; the rest element is Fe. By adjusting the atomic ratio of each element, the nano-sized precipitates are generated as much as possible, and the strength is maximized while maintaining a high plasticity. The stainless steels provided by this invention have only five alloying components, a low manufacturing cost, and high-strength and high-plasticity. They can be widely used in many industrial fields such as aviation, aerospace, marine, and nuclear power with broad market prospects.