Ceratizit Austria Gesellschaft M.b.h.

Schwarzkopf Development Corporation

Wolfgang Glätzle

Andreas Lackner

Rolf Kösters

Helmut Beirer

Erwin Hartlmayr

Johannes Glätzle

Gerhard Knünz

Udo Gennari

A component is produced by powder metallurgy from hard metal. The alloy includes at least one grain growth-inhibiting additive from the group consisting of V, Cr, Ti, Ta and Nb with, at least locally, a graduated concentration profile. As a result, the mechanical properties also have a graduated profile. In the fabrication process, a dispersion or solution which contains the grain growth-inhibiting additive in finely distributed or dissolved form is applied to the surface of a green compact. Penetration of this dispersion or solution along open pores leads to a graduated distribution of the grain growth-inhibiting additive in the green compact. There is also described a process in which the grain growth-inhibiting additive in the form of a solution is distributed uniformly in the green compact and is then gradually broken down from edge regions by a heat treatment or a solvent.

Method of producing a hard metal component with a graduated structure

A hard metal granulate is produced by wet milling and spray drying in a spray tower using pure water as the liquid phase. The spray tower is configured and operated in such a way that a ratio of the quantity of water added via the slurry (in liters per hour) to tower volume (in m) is between 0.5 and 1.8 and in that a maximum of 0.17 kg of slurry is atomized per mof incoming drying gas. The slurry has a solid particle concentration within a range of 65-85% by weight. Under these conditions, the addition of a water-soluble, long-chain polyglycol to the slurry prior to spraying previously required in order to prevent oxidation of the hard metal granulate is no longer necessary.

Method for producing hard metal granulate

Process for producing an ODS sintered alloy

The invention relates to a process for producing a superconducting wire, using, e.g., Chevrel phases as superconductors, in particular PbMo.sub.6 S.sub.8. Until now, it was not possible to produce superconducting wires from such materials in a technically usable quality. According to the process of the invention, the superconducting Chevrel phase is loaded vacuum-tight into a molybdenum shell and the unit is advantageously sealed in another jacket made of steel. The powdery superconducting phase has an average grain size of less than 1 .mu.m. For shaping the superconducting wire, the unit is extruded in a first process step at temperatures between 1000.degree. and 1600.degree. C. and reduced in cross section in excess of 1:10, and subsequently further treated in a plurality of process steps by additional extruding and/or hot drawing. Superconducting wires produced as specified above exhibit values for the critical quantities such as current bearing capacity, critical current density and limit values of the magnetic field that conform to those of the technically sophisticated superconductors of type II, or surpass the values of the latter type in individual instances. At the same time, it was possible to wind such wires to form coils without impairing the superconducting values due to the brittleness of the Chevrel phases.

Process for producing a superconducting wire having a Chevrel phases

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Reutte, Austria

Wolfgang Glätzle