摘要:
Process for producing an elongated superconductor with a bismuth phase having a high transition temperature and a superconductor produced according to this process. An elongated superconductor with at least one conductor core made of high-T.sub.c Bi-containing superconductor material with the 2212 or 2223 phase is to be manufactured. For this purpose, the cross section of a structure made of Ag matrix material and a precursor of the superconductor material is reduced. Subsequently the raw conductor thus obtained is annealed in an oxygen-containing atmosphere. According to this invention, a temperature variation between a higher temperature (T1) and a lower temperature (T2) is provided for the annealing. The higher temperature (T1) is at most 7 K above the decomposition temperature (Tz), and the lower temperature (T2) is at most 9 K below the decomposition temperature (Tz).
摘要:
A carrier material for a tool for treating surfaces is composed of a metal alloy with a homogeneous, fine-grained structure. The carrier material is treated in a material removing manner to obtain a predetermined size and a roughness. Then an activating layer, a pure metal layer and a transition layer composed for example from nitrogen are applied, so that the outermost region of the tool contains a non-metallic hard layer. The non-metallic hard layer has a high hardness and elasticity so that the tool is suitable especially for treating surfaces of structural parts.
摘要:
A tool for machining of openings, shafts and the like has a body having concentrical stepped cylindrical working regions, grooves provided between the working regions, and transitional regions arranged between the grooves and the cylindrical working regions. The transitional regions extend substantially tangentially in a machining direction and a deformation process of an outer surface of the workpiece to be machined is performed without material removal by compression.
摘要:
A composite superconductor comprises a matrix of an alloy which is normally conductive at operating temperatures with the alloy being copper and another alloying element. Several superconducting filaments are embedded in the matrix with these filaments being formed by a diffusion reaction between at least two elements. An aluminum jacket surrounds the matrix. A barrier layer formed from at least one intermetallic copper-aluminum compound is disposed between the aluminum jacket and the alloy matrix. The aluminum jacket may be formed by extrusion at an elevated temperature with the boundary layer between the aluminum jacket and the alloy matrix being concurrently formed by diffusion.
摘要:
The invention concerns a method for the manufacture of a superconductor which comprises a superconductive, intermetallic compound including at least two elements. A ductile component of at least one element of the compound is brought into contact with a ductile carrier metal bearing the other elements of the compound. The structure so obtained is heat-treated in a vapor formed over a separate melt of the elements found in the carrier metal in such a manner that the intermetallic compound is formed through reaction of the vapor, diffusing through the carrier metal, with the ductile component. The heat treatment applied until the ductile components and the other elements reach the same temperature is performed in a vacuum with a residual maximum gas pressure of 10.sup.-.sup.2 Torr or in an inert gas at a maximum gas pressure of 500 Torr.