The present invention relates to a spiral spring for a balance wheel made of an alloy of niobium and titanium with an essentially single-phase structure, and the method of manufacture thereof which comprises: a step of producing a blank in a niobium-based alloy consisting of: niobium: balance to 100 wt %, titanium: between 40 and 49 wt %, traces of elements selected from the group consisting of O, H, C, Fe, Ta, N, Ni, Si, Cu, Al, between 0 and 1600 ppm by weight individually, and cumulatively less than 0.3 wt %, a step of type β hardening of said blank at a given diameter, in such a way that the titanium of the niobium-based alloy is essentially in the form of a solid solution with niobium in β phase, the content of titanium in α phase being less than or equal to 10 vol %, at least one deformation step of said alloy alternating with at least one step of heat treatment, the number of steps of heat treatment and of deformation being limited so that the niobium-based alloy obtained retains a structure in which the titanium of the niobium-based alloy is essentially in the form of a solid solution with niobium in β phase, the content of titanium in α phase being less than or equal to 10 vol % and it has an elastic limit greater than or equal to 600 MPa and an elastic modulus less than or equal to 100 GPa, a step of winding to form the spiral spring being carried out before the last heat treatment step.

A balance spring intended to equip a balance of a horological movement, wherein the balance spring is made of an alloy consisting of Nb, Ti, H and possible traces of other elements selected from O, C, Fe, N, Ni, Si, Cu and Al, with the following weight percentages: a Ti content comprised between 1 and 80 wt %, a H content comprised between 0.17 and 2 wt %, a total content of all other elements of less than or equal to 0.3 wt %, the remainder to 100 wt % consisting of Nb. A manufacturing method for the balance spring is also disclosed and includes a step of thermochemically treating a blank made of a Nb and Ti alloy in an atmosphere including hydrogen so as to enrich the Nb and Ti alloy with hydrogen in interstitial form.

A balance spring intended to equip a balance of a horological movement, wherein the balance spring is made of an alloy consisting of Nb, Ti, H and possible traces of other elements selected from O, C, Fe, N, Ni, Si, Cu and Al, with the following weight percentages: a Ti content comprised between 1 and 80 wt %, a H content comprised between 0.17 and 2 wt %, a total content of all other elements of less than or equal to 0.3 wt %, the remainder to 100 wt % consisting of Nb. A manufacturing method for the balance spring is also disclosed and includes a step of thermochemically treating a blank made of a Nb and Ti alloy in an atmosphere including hydrogen so as to enrich the Nb and Ti alloy with hydrogen in interstitial form.

The present invention relates to a spiral spring for a balance wheel made of an alloy of niobium and titanium with an essentially single-phase structure, and the method of manufacture thereof which comprises: a step of producing a blank in a niobium-based alloy consisting of: niobium: balance to 100 wt %, titanium: between 40 and 49 wt %, traces of elements selected from the group consisting of O, H, C, Fe, Ta, N, Ni, Si, Cu, Al, between 0 and 1600 ppm by weight individually, and cumulatively less than 0.3 wt %, a step of type β hardening of said blank at a given diameter, in such a way that the titanium of the niobium-based alloy is essentially in the form of a solid solution with niobium in β phase, the content of titanium in α phase being less than or equal to 10 vol %, at least one deformation step of said alloy alternating with at least one step of heat treatment, the number of steps of heat treatment and of deformation being limited so that the niobium-based alloy obtained retains a structure in which the titanium of the niobium-based alloy is essentially in the form of a solid solution with niobium in β phase, the content of titanium in α phase being less than or equal to 10 vol % and it has an elastic limit greater than or equal to 600 MPa and an elastic modulus less than or equal to 100 GPa, a step of winding to form the spiral spring being carried out before the last heat treatment step.

The present invention relates to a spiral spring for a balance wheel made of an alloy of niobium and titanium with an essentially single-phase structure, and the method of manufacture thereof which comprises: a step of producing a blank in a niobium-based alloy consisting of: niobium: balance to 100 wt %, titanium: between 40 and 49 wt %, traces of elements selected from the group consisting of O, H, C, Fe, Ta, N, Ni, Si, Cu, Al, between 0 and 1600 ppm by weight individually, and cumulatively less than 0.3 wt %, a step of type β hardening of said blank at a given diameter, in such a way that the titanium of the niobium-based alloy is essentially in the form of a solid solution with niobium in β phase, the content of titanium in α phase being less than or equal to 10 vol %, at least one deformation step of said alloy alternating with at least one step of heat treatment, the number of steps of heat treatment and of deformation being limited so that the niobium-based alloy obtained retains a structure in which the titanium of the niobium-based alloy is essentially in the form of a solid solution with niobium in β phase, the content of titanium in α phase being less than or equal to 10 vol % and it has an elastic limit greater than or equal to 600 MPa and an elastic modulus less than or equal to 100 GPa, a step of winding to form the spiral spring being carried out before the last heat treatment step.

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.

The invention relates to a method for cutting refractory metals, in which a solid body (1) made of a refractory metal is mechanically machining cut with a cutting apparatus (4, 7), wherein the cutting apparatus (4, 7) is wetted for cutting with a fluid (6) having at least 50 weight % water, wherein the cutting apparatus (4, 7) is brought to a positive electrical potential in relation to the solid body (1) during cutting. The invention also relates to a disc produced from a refractory metal using such a method, and such a disc that has an oxide layer with a thickness of between 2 nm and 1,000 nm on the cutting surface.

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.