Abstract: The sheath (3) is a material, which includes an aluminium (Al) matrix, in which nanometric aluminium oxide particles (Al2O3) are homogenously dispersed, the content of Al2O3 is 0.25 to 5 vol. % and the balance is Al. It is preferred that Al2O3 originates from the surface layer present on Al powder used as feedstock material for consolidation. The superconductor based on magnesium diboride (MgB2) core (1) is fabricated by powder-in-tube or internal magnesium diffusion to boron technology, while the tube is the Al+Al2O3 composite, which is a product of powder metallurgy. A loose Al powder is pressed by cold isostatic pressing, and then the powder billet is degassed at elevated temperature and under vacuum, and then is hot extruded into a tube. A thin diffusion barrier (2) tube filled up with a mixture of Mg and B powders or Mg wire surrounded with B powder is placed into the Al+Al2O3 composite tube under inert gas or vacuum. Such composite unit is cold worked into a thin wire and then annealed at 625-655° C.

Abstract: Foamable semifinished product (1) in the form of granules produced from the metal alloy and the foam agent is inserted into the cavity of the closable mould (2) and the liquid (3) with the density that is higher than the apparent (or bulk) density of the resulting foam is led to it. The liquid has a temperature which is higher than the temperature of the melting of the metal alloy; the transfer of the heat to the particles of the foamable semifinished product (1) takes place; it subsequently expands, whereby it is supported by the liquid (3). During the expansion at least part of the liquid (3) is pushed by the expansion itself out of the mould (2) through the opening. The liquid (3) allows the regulation of the pressure of the environment of the foam agent, too, which helps to set exactly the moment of expansion. The metal melt can be advantageously used as liquid (3). The melt can partially remain in the mould (2) so the hybrid structure of the component is created.

Abstract: The sheath (3) is a material, which includes an aluminium (Al) matrix, in which nanometric aluminium oxide particles (Al2O3) are homogenously dispersed, the content of Al2O3 is 0.25 to 5 vol. % and the balance is Al. It is preferred that Al2O3 originates from the surface layer present on Al powder used as feedstock material for consolidation. The superconductor based on magnesium diboride (MgB2) core (1) is fabricated by powder-in-tube or internal magnesium diffusion to boron technology, while the tube is the Al+Al2O3 composite, which is a product of powder metallurgy. A loose Al powder is pressed by cold isostatic pressing, and then the powder billet is degassed at elevated temperature and under vacuum, and then is hot extruded into a tube. A thin diffusion barrier (2) tube filled up with a mixture of Mg and B powders or Mg wire surrounded with B powder is placed into the Al+Al2O3 composite tube under inert gas or vacuum. Such composite unit is cold worked into a thin wire and then annealed at 625-655° C.

Abstract: Composite for the transfer of the heat between the hot and cooled surface, whereby the composite is resistant to high temperatures, includes at least two components, one of the components is produced by longitudinal segments (1) with the melting temperature that is higher than 1300° C. and which are separated from each other by the filling (2) with the higher heat conductivity and thermal expansivity, which is in the direct contact with the cooling medium in the channel (3). Both components are in the direct contact with the hot environment surrounding the composite, whereby the overall surface formed by the segments (1) is 50 to 95% of the overall hot surface of the composite. The longitudinal axis of the segment (1) is primarily oriented in the direction of the shortest line connecting the hot surface with the cooled surface of the composite with the allowed deviation of 45° at maximum, whereby in the direction from the hot to the cooled surface it can cross one boundary between the components at maximum.

Abstract: Composite for the transfer of the heat between the hot and cooled surface, whereby the composite is resistant to high temperatures, includes at least two components, one of the components is produced by longitudinal segments (1) with the melting temperature that is higher than 1300° C. and which are separated from each other by the filling (2) with the higher heat conductivity and thermal expansivity, which is in the direct contact with the cooling medium in the channel (3). Both components are in the direct contact with the hot environment surrounding the composite, whereby the overall surface formed by the segments (1) is 50 to 95% of the overall hot surface of the composite. The longitudinal axis of the segment (1) is primarily oriented in the direction of the shortest line connecting the hot surface with the cooled surface of the composite with the allowed deviation of 45° at maximum, whereby in the direction from the hot to the cooled surface it can cross one boundary between the components at maximum.

Abstract: Foamable semifinished product (1) in the form of granules produced from the metal alloy and the foam agent is inserted into the cavity of the closable mould (2) and the liquid (3) with the density that is higher than the apparent (or bulk) density of the resulting foam is led to it. The liquid has a temperature which is higher than the temperature of the melting of the metal alloy; the transfer of the heat to the particles of the foamable semifinished product (1) takes place; it subsequently expands, whereby it is supported by the liquid (3). During the expansion at least part of the liquid (3) is pushed by the expansion itself out of the mould (2) through the opening. The liquid (3) allows the regulation of the pressure of the environment of the foam agent, too, which helps to set exactly the moment of expansion. The metal melt can be advantageously used as liquid (3). The melt can partially remain in the mould (2) so the hybrid structure of the component is created.