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US 4,290,827 AGranted
Process for producing Ni-Fe magnetic tape cores
AssigneeVacuumschmelze GmbH & Co. KG
InventorsFriedrich Pfeifer, Wernfried Behnke
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AssigneeVacuumschmelze GmbH & Co. KG
InventorsFriedrich Pfeifer, Wernfried Behnke
Estimating the term…
An alloy comprised of 45 to 53 wt. % Ni with the remainder iron, and including small amounts of deoxidizing and processing additives is worked into a 0.01 to 0.1 mm thick tape, wound to form a tape core and is then subjected to a final annealing for at least one hour at a temperature of at least 900.degree. C. and thereafter is subjected to a tempering in a magnetic cross-field (i.e., the magnetic lines of force are applied in the plane of the tape perpendicular to the rolling direction thereof). The process provides high impulse permeabilities at induction rises of 1T or larger within the so-processed tape cores. Particularly high impulse permeabilities are achieved in instances where an anisotropic structure with a privileged grain direction <001> in the rolling direction is generated in the tape material via heating and final deformation before winding into a tape core and via a final annealing after winding of the tape core. The so-produced tape cores are useful in various electrical applications, particularly in pulse transformers and thyristor choke coils.
In a process for producing tape cores composed of a Ni-Fe alloy having 45 to 53 weight percent nickel with the remainder iron and including relatively small amounts of deoxidizing and processing additives whereby an ingot composed of said alloy is worked into a tape having a thickness of about 0.01 to 0.1 mm and wound into a tape core, which tape core is then subjected to at least a one hour final annealing at a temperature of at least about 900.degree. C. and the so-annealed tape core is then subjected to a tempering treatment in a magnetic field in which the lines of force are applied in the tape plane perpendicular to the rolling direction of the tape, the improvement comprising wherein:
In a process for producing tape cores composed of a Ni-Fe alloy having 45 to 53 weight percent nickel with the remainder iron and including relatively small amounts of deoxidizing and processing additives whereby an ingot composed of said alloy is worked into a tape having a thickness of about 0.01 to 0.1 mm and wound into a tape core, which tape core is then subjected to at least a one hour final annealing at a temperature of at least about 900.degree. C. and the so-annealed tape core is then subjected to a tempering treatment in a magnetic field in which the lines of force are applied in the tape plane perpendicular to the rolling direction of the tape, the improvement comprising:
A Ni-Fe magnetic tape core comprised of 45 to 53 weight percent nickel with the remainder iron and including relatively small amounts of deoxidizing and processing additives, characterized by a secondary recrystallization structure therein and a relatively high impulse permeability of about 8300 with an induction rise of 1.0T, about 6400 with an induction rise of 1.2T, about 4800 with an induction rise of 1.3T and about 2900 with an induction rise of 1.4T.
A Ni-Fe magnetic tape core comprised of 45 to 53 weight percent nickel with the remainder iron and including relatively small amounts of deoxidizing and processing additives, characterized by a structure therein having a privileged (210) <001>
Dependencies are inferred from the claim text.