US4257830A — Method of manufacturing a thin ribbon of magnetic…

Claim 1

Independent Claim 167 words

A method of manufacturing a thin ribbon of magnetic material having a high permeability and excellent flexibility and workability comprising the steps of: melting a magnetic material consisting essentially of by weight of 4-7% of aluminum, 8-11% of silicon and the remainder iron and inevitable impurities of less than 0.5%, at a temperature between the melting point and a temperature not exceeding about 300° C. above the melting point; ejecting the resultant melt through a nozzle under a pressure of from about 0.01 to 1.5 atm. onto a moving surface of a cooling substrate; and cooling the melt on said moving surface of said cooling substrate at a cooling rate of from about 10 3 to 10 6 ° C./sec to form a thin ribbon having a compact and fine grain size structure, wherein the fine crystal grain structure is essentially composed of columnar grains aligned perpendicular to the surface of the thin ribbon and having a mean grain diameter of from about 1 to 100 μm.

Claim 2

Independent Claim 167 words

A method of manufacturing a thin ribbon of magnetic material having a high permeability and excellent flexibility and workability comprising the steps of: melting a magnetic material consisting essentially of by weight of 4-7% of aluminum, 8-11% of silicon and the remainder iron and inevitable impurities of less than 0.5%, at a temperature between the melting point and a temperature not exceeding about 300° C. above the melting point; ejecting the resultant melt through a nozzle under a pressure of from about 0.01 to 1.5 atm. onto a moving surface of a cooling substrate; and cooling the melt on said moving surface of said cooling substrate at a cooling rate of from about 10 3 to 10 6 ° C./sec to form a thin ribbon having a compact and fine grain size structure, wherein the fine crystal grain structure is essentially composed of columnar grains aligned perpendicular to the surface of the thin ribbon and having a mean grain diameter of from about 1 to 100 μm.

Claim 3

Dependent Claim 78 words

A method as defined in claim 1, wherein the composition of said melt of thin ribbon material consists of by weight 4-7% of aluminum, 8-11% of silicon, and the remainder iron and inevitable impurities of less than 0.5% and at least one element of less than 7% by weight in total selected from the group consisting of vanadium, niobium, tantalum, chromium, molybdenum, tungsten, copper, titanium, manganese, germanium, zirconium, antimony, tin, beryllium, boron, bismuth, lead, yttrium and rare-earth metal.

Claim 4

Dependent Claim 50 words

A method as defined in claim 1, wherein the composition of said melt consists of by weight 4-7% of aluminum, 8-11% of silicon, and the remainder iron and inevitable impurities as main ingredients and at least one element selected from 0.01-2% of manganese, 0.01-10% of cobalt and 0.01-3% of nickel.

Claim 5

Dependent Claim 28 words

A method as defined in claim 1, wherein said cooling substrate is selected from drum-type, disc-type, twin roll type and belt conveyor type with or without backup roll.

Claim 6

Dependent Claim 33 words

A method as defined in claim 1, wherein the melt is ejected through a nozzle having a plurality of nozzle holes arranged adjacent to each other in the lateral direction of thin ribbon.

Claim 7

Dependent Claim 36 words

A method as defined in claim 1, wherein the melt is ejected through a nozzle cooled by water in the peripheral portion of nozzle hole and cooled super rapidly on the moving surface of cooling substrate.

Claim 8

Dependent Claim 49 words

A method as defined in claim 1, wherein said nozzle for ejecting melt is made of a heat resistant material selected from the group consisting of boron nitride, silicon nitride, silicon carbide, ceramics, fused silica, semi-fused alumina, magnesia, beryllium, platinum, platinum-rhodium, tungsten, molybdenum, tantalum, titanium and carbon, alloys thereof.

Claim 9

Dependent Claim 26 words

A method as defined in claim 9, wherein the nozzle is lined with boron nitride in at least the edge and inner edge portion of nozzle.

Claim 10

Dependent Claim 29 words

A method as defined in claim 1, wherein the cooling substrate is made of material selected from the group consisting of copper, copper-beryllium, brass, stainless steel and carbon steel.

Claim 11

Dependent Claim 28 words

A method as defined in claim 1, wherein the nozzle comprises a single nozzle hole or a plurality of nozzle holes selected from circular, elliptical and rectangular configurations.

Claim 12

Independent Claim 208 words

A method of manufacturing a thin ribbon of magnetic material having high permeability and excellent flexibility and workability comprising the steps of: melting a magnetic material consisting essentially of by weight 4-7% of aluminum, 8-11% of silicon and the remainder iron and impurities of less than about 0.5% at a temperature between the melting point and a temperature not exceeding 300° C. from the melting point and adjusting a viscosity of said melt to from about 5.5×10 -2 to 3×10 -2 dyne sec/cm 2 ; ejecting the resultant melt through a nozzle under a pressure of from about 0.01 to 1.5 atm. onto a moving surface of a cooling substrate; cooling the melt on the moving surface of said cooling substrate at a cooling rate of from about 10 3 to 10 6 ° C./sec to form a thin ribbon having a compact and fine grain size structure having a mean grain diameter of from about 1 to 100 μm and; annealing the resulting thin ribbon at a temperature of between 600° to 1,000° C. for from about 1 minute to 5 hours, so as to obtain a column-like crystal structure having a grain size of from about 0.01-10 mm by promoting the growth of crystal grain size.

Claim 13

Independent Claim 208 words

A method of manufacturing a thin ribbon of magnetic material having high permeability and excellent flexibility and workability comprising the steps of: melting a magnetic material consisting essentially of by weight 4-7% of aluminum, 8-11% of silicon and the remainder iron and impurities of less than about 0.5% at a temperature between the melting point and a temperature not exceeding 300° C. from the melting point and adjusting a viscosity of said melt to from about 5.5×10 -2 to 3×10 -2 dyne sec/cm 2 ; ejecting the resultant melt through a nozzle under a pressure of from about 0.01 to 1.5 atm. onto a moving surface of a cooling substrate; cooling the melt on the moving surface of said cooling substrate at a cooling rate of from about 10 3 to 10 6 ° C./sec to form a thin ribbon having a compact and fine grain size structure having a mean grain diameter of from about 1 to 100 μm and; annealing the resulting thin ribbon at a temperature of between 600° to 1,000° C. for from about 1 minute to 5 hours, so as to obtain a column-like crystal structure having a grain size of from about 0.01-10 mm by promoting the growth of crystal grain size.

Claim 14

Dependent Claim 46 words

A method as defined in claim 11, wherein a rotating cooling substrate has a good wettability to the melt and the melt is cooled at a sufficient super-rapid cooling of 10 3 -10 6 ° C./sec during the instantaneous adhering and moving on the cooling substrate.

Claim 15

Dependent Claim 69 words

A method as defined in claim 11, wherein a melting temperature of the melt is suitably selected from the temperature range of between the melting point and a temperature not exceeding 300° C. from the melting point and the viscosity is adjusted with respect to the ejecting pressure of 0.01-1.5 atm so as to avoid forming a mist, small tablets or rattan blind, corrugated ribbon or periphery shredded ribbon.

Claim 16

Dependent Claim 71 words

A thin ribbon of magnetic material having a high permeability, excellent flexibility and workability consisting essentially of by weight 4-7% of aluminum, 8-11% of silicon and the remainder being iron and inevitable impurities and having a compact fine grain structure with a mean grain diameter from about 1 to 100 μm, wherein the fine crystal grains are essentially of columnar grain structure aligned perpendicular to the surface of the thin ribbon.

Claim 17

Dependent Claim 71 words

A thin ribbon of magnetic material having a high permeability, excellent flexibility and workability consisting essentially of by weight 4-7% of aluminum, 8-11% of silicon and the remainder being iron and inevitable impurities and having a compact fine grain structure with a mean grain diameter from about 1 to 100 μm, wherein the fine crystal grains are essentially of columnar grain structure aligned perpendicular to the surface of the thin ribbon.

Claim 18

Dependent Claim 94 words

A thin ribbon of magnetic material having a compact fine grain crystal structure, a high permeability, excellent flexibility and workability, consisting essentially of by weight 4-7% of aluminum, 8-11% of silicon, at least one element selected from the group consisting of 0.01-2% of maganese, 0.01-10% of cobalt and 0.01-3% of nickel and the remainder being iron and inevitable impurities, wherein the compact fine grain crystal structure is composed essentially of columnar grains aligned perpendicular to the surface of the thin ribbon and has a mean grain diameter of from about 1 to 100 μm.

Claim 19

Dependent Claim 94 words

A thin ribbon of magnetic material having a compact fine grain crystal structure, a high permeability, excellent flexibility and workability, consisting essentially of by weight 4-7% of aluminum, 8-11% of silicon, at least one element selected from the group consisting of 0.01-2% of maganese, 0.01-10% of cobalt and 0.01-3% of nickel and the remainder being iron and inevitable impurities, wherein the compact fine grain crystal structure is composed essentially of columnar grains aligned perpendicular to the surface of the thin ribbon and has a mean grain diameter of from about 1 to 100 μm.

Claim 20

Dependent Claim 31 words

A thin ribbon of magnetic material having a high permeability as defined in claim 14, wherein said inevitable impurities are less than 1% in total of carbon, nitrogen oxygen and sulphur.

Claim 21

Dependent Claim 81 words

A magnetic recording and reproducing head comprising at least one thin ribbon of a magnetic material consisting essentially of by weight 4-7% of aluminum, 8-11% of silicon and the remainder being iron and inevitable impurities of less than 0.5% having a compact fine grain crystal structure, wherein the compact fine grain crystal structure is composed essentially of columnar grains aligned perpendicular to the surface of the thin ribbon and having a mean grain diameter of from about 1 to 100 μm.

Claim 22

Dependent Claim 81 words

A magnetic recording and reproducing head comprising at least one thin ribbon of a magnetic material consisting essentially of by weight 4-7% of aluminum, 8-11% of silicon and the remainder being iron and inevitable impurities of less than 0.5% having a compact fine grain crystal structure, wherein the compact fine grain crystal structure is composed essentially of columnar grains aligned perpendicular to the surface of the thin ribbon and having a mean grain diameter of from about 1 to 100 μm.

Claim 23

Dependent Claim 64 words

A magnetic recording and reproducing head as defined in claim 23, wherein said thin ribbon is annealed at a temperature of 600°-1,000° C. from about 1 minute to 5 hours after forming a magnetic recording and reproducing head whereby said thin ribbon has an ordered lattice, more than 500 of Vickers hardness and a mean grain diameter of from about 1 to 100 μm.

Claim 24

Dependent Claim 80 words

A thin ribbon of magnetic material having a high permeability, excellent flexibility and workability consisting essentially of by weight 4-7% of aluminum, 8-11% of silicon and the remainder being iron and inevitable impurities and having a crystal grain structure with ordered lattice having a mean grain size of 0.01-10 mm, wherein the crystal grains are promoted to a columnar grain structure aligned perpendicular to the surface of the thin ribbon and having a grain size of from about 0.01-10 mm.

Claim 25

Dependent Claim 80 words

A thin ribbon of magnetic material having a high permeability, excellent flexibility and workability consisting essentially of by weight 4-7% of aluminum, 8-11% of silicon and the remainder being iron and inevitable impurities and having a crystal grain structure with ordered lattice having a mean grain size of 0.01-10 mm, wherein the crystal grains are promoted to a columnar grain structure aligned perpendicular to the surface of the thin ribbon and having a grain size of from about 0.01-10 mm.

Claim 26

Dependent Claim 18 words

The method of claim 1 wherein the mean grain diameter is from about 1 to about 100 μm.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1984-03-23	1984-09-22	1985-03-24	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1988-03-23	1988-09-22	1989-03-24	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1992-03-23	1992-09-22	1993-03-24	$7700.00	Window Closed / Lapsed

Method of manufacturing a thin ribbon of magnetic material

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