A negative electrode active material having high cycle durability contains an alloy represented by the following chemical formula (1):
Si.sub.xSn.sub.yM.sub.zA.sub.a(1)
(in the chemical formula (1), M is at least one metal selected from the group consisting of Ti, Zn, C, and combinations thereof, A is unavoidable impurities, x, y, z, and a represent % by mass values, and in that case, 0<x<100, 0<y<100, 0<z<100, 0a<0.5, and x+y+z+a=100), in which the half width of the diffraction peak of the (111) surface of Si in the range of 2=24 to 33 by X ray diffraction measurement of the alloy using the CuK ray is 0.7 or more.

A negative electrode active material having high cycle durability contains an alloy represented by the following chemical formula (1):
Si.sub.xSn.sub.yM.sub.zA.sub.a(1)
(in the chemical formula (1), M is at least one metal selected from the group consisting of Ti, Zn, C, and combinations thereof, A is unavoidable impurities, x, y, z, and a represent % by mass values, and in that case, 0<x<100, 0<y<100, 0<z<100, 0a<0.5, and x+y+z+a=100), in which the half width of the diffraction peak of the (111) surface of Si in the range of 2=24 to 33 by X ray diffraction measurement of the alloy using the CuK ray is 0.7 or more.

A negative electrode for an electrical device includes: a current collector; and an electrode layer containing a negative electrode active material, an electrically-conductive auxiliary agent and a binder and formed on a surface of the current collector, wherein the negative electrode active material contains an alloy represented by a following formula (1): Si.sub.xZn.sub.yM.sub.zA.sub.a (in the formula (1) M is at least one metal selected from the group consisting of V, Sn, Al, C and combinations thereof, A is inevitable impurity, and x, y, z and a represent mass percent values and satisfy 0<x<100, 0<y<100, 0<z<100, 0a<0.5 and x+y+z+a=100), and elongation () of the electrode layer is 1.29<<1.70%.

A negative electrode for an electrical device includes: a current collector; and an electrode layer containing a negative electrode active material, an electrically-conductive auxiliary agent and a binder and formed on a surface of the current collector, wherein the negative electrode active material contains an alloy represented by a following formula (1): Si.sub.xZn.sub.yM.sub.zA.sub.a (in the formula (1) M is at least one metal selected from the group consisting of V, Sn, Al, C and combinations thereof, A is inevitable impurity, and x, y, z and a represent mass percent values and satisfy 0<x<100, 0<y<100, 0<z<100, 0a<0.5 and x+y+z+a=100), and elongation () of the electrode layer is 1.29<<1.70%.

A NiCrFe-based alloy brazing filler material to which Cu is added, and which has a low melting temperature, and is inexpensive and excellent in corrosion resistance and in strength, for use in manufacture of stainless-steel heat exchangers or the like, specifically, a NiCrFe-based alloy brazing filler material, including, in mass %, Cr: 15 to 30%; Fe: 15 to 30%; Cu: 2.1 to 7.5%; P: 3 to 12%; and Si: 0 to 8%; and the balance being Ni and unavoidable impurities, wherein the total content of Cr and Fe is 30 to 54%, and the total content of P and Si is 7 to 14%.

A NiCrFe-based alloy brazing filler material to which Cu is added, and which has a low melting temperature, and is inexpensive and excellent in corrosion resistance and in strength, for use in manufacture of stainless-steel heat exchangers or the like, specifically, a NiCrFe-based alloy brazing filler material, including, in mass %, Cr: 15 to 30%; Fe: 15 to 30%; Cu: 2.1 to 7.5%; P: 3 to 12%; and Si: 0 to 8%; and the balance being Ni and unavoidable impurities, wherein the total content of Cr and Fe is 30 to 54%, and the total content of P and Si is 7 to 14%.

There is provided a Cr-based two-phase alloy including two phases of a ferrite phase and an austenite phase that are mixed with each other. A chemical composition of the Cr-based two-phase alloy consists of a main component, an auxiliary component, impurities, a first optional auxiliary component, and a second optional auxiliary component. The main component consists of 33-61 mass % Cr, 18-40 mass % Ni and 10-33 mass % Fe, and a total content of the Ni and the Fe is 37-65 mass %. The auxiliary component consists of 0.1-2 mass % Mn, 0.1-1 mass % Si, 0.005-0.05 mass % Al, and 0.02-0.3 mass % Sn. The impurities include 0.04 mass % or less of P, 0.01 mass % or less of S, 0.03 mass % or less of C, 0.04 mass % or less of N, and 0.05 mass % or less of O.

There is provided a Cr-based two-phase alloy including two phases of a ferrite phase and an austenite phase that are mixed with each other. A chemical composition of the Cr-based two-phase alloy consists of a main component, an auxiliary component, impurities, a first optional auxiliary component, and a second optional auxiliary component. The main component consists of 33-61 mass % Cr, 18-40 mass % Ni and 10-33 mass % Fe, and a total content of the Ni and the Fe is 37-65 mass %. The auxiliary component consists of 0.1-2 mass % Mn, 0.1-1 mass % Si, 0.005-0.05 mass % Al, and 0.02-0.3 mass % Sn. The impurities include 0.04 mass % or less of P, 0.01 mass % or less of S, 0.03 mass % or less of C, 0.04 mass % or less of N, and 0.05 mass % or less of O.

A composite tube is provided that includes a first tube and a second tube. A chemical composition of the first tube includes, in mass %, C: more than 0.060% to 0.400% or less, Si: 0.01 to 1.00%, Mn: 0.01 to 1.20%, P: 0.0350% or less, S: 0.0150% or less, Sn: 0.0005 to 0.0400%, Al: 0.040% or less, N: 0.050% or less, O: 0.030% or less, and the balance: Fe and impurities. A chemical composition of the second tube includes, in mass %, C: 0.003 to 0.100%, Si: 0.01 to 1.50%, Mn: 0.01 to 2.20%, P: 0.0400% or less, S: 0.0100% or less, Sn: 0.0005 to 0.0300%, Ni: 7.0 to 52.0%, Cr: 15.0 to 27.0%, Al: 0.001 to 0.600%, N: 0.001 to 0.150%, O: 0.030% or less, and the balance: Fe and impurities. The composite tube satisfies formulas [Si.sub.ave+6?P.sub.ave+20?S.sub.ave+2?Sn.sub.ave?1.1000] and [0.0015?4?S.sub.ave+Sn.sub.ave].

A composite tube is provided that includes a first tube and a second tube. A chemical composition of the first tube includes, in mass %, C: more than 0.060% to 0.400% or less, Si: 0.01 to 1.00%, Mn: 0.01 to 1.20%, P: 0.0350% or less, S: 0.0150% or less, Sn: 0.0005 to 0.0400%, Al: 0.040% or less, N: 0.050% or less, O: 0.030% or less, and the balance: Fe and impurities. A chemical composition of the second tube includes, in mass %, C: 0.003 to 0.100%, Si: 0.01 to 1.50%, Mn: 0.01 to 2.20%, P: 0.0400% or less, S: 0.0100% or less, Sn: 0.0005 to 0.0300%, Ni: 7.0 to 52.0%, Cr: 15.0 to 27.0%, Al: 0.001 to 0.600%, N: 0.001 to 0.150%, O: 0.030% or less, and the balance: Fe and impurities. The composite tube satisfies formulas [Si.sub.ave+6?P.sub.ave+20?S.sub.ave+2?Sn.sub.ave?1.1000] and [0.0015?4?S.sub.ave+Sn.sub.ave].