Hitachi Metals, Ltd.

Hitachi, Ltd.

Hitachi Research Dev. Corp.

Yoshizo Sawada

Yasunobu Ogata

Mitsuhiro Kudo

Shinji Takayama

Takashi Meguro

Kazuo Shiiki

Shigekazu Otomo

Shunsuke Arakawa

Yasuo Tsukuda

A method of manufacturing an amorphous metal sheet or ribbon which comprises extruding a molten metal from an orifice of a nozzle and directing the extruded molten metal onto a moving chill surface to rapidly cool and solidify the metal thereby forming said sheet or ribbon; said orifice being a rectangular slit defined by side walls and a front lip and a back lip arranged in front and behind the slit in the direction of movement of the chill surface below said nozzle; said chill surface moving a speed of 10 m/sec to 50 m/sec and being spaced from the front lip by a gap length of from 100 .mu.m to 600 .mu.m and the width W.sub.F of the front lip measured in the direction of movement of the chill surface being represented by the relationship W.sub.F .ltoreq.W, wherein W represent the width the slot in the nozzle.

Method of producing thin metal ribbon

Amorphous alloys having high strength, high hardness, high crystallization temperature, high saturation magnetic induction, low coercive force, high magnetic permeability and particularly low deterioration of magnetic properties with lapse of time, have a composition formula of

Amorphous alloys

An alloy material for magnetic head which ensures, when formed into a head, reduced distortion during writing and reduced level of noises such as sliding noise, while presenting high wear resistance. The alloy material is produced by preparing a molten alloy having a basic composition consisting essentially of Fe and 4 to 8 wt % of Si, and further containing one or more than two additive element or elements selected from a group consisting of elements belonging in periodic table to groups IIA, IVB, VB, VIB, VIIB, VIII, IB, IIB, IIIA, IVA and VA. The molten alloy is then quenched at a high cooling rate of at least 10.sup.3 .degree.C./sec to become a thin sheet having a thickness ranging between 0.02 mm and 0.3 mm. The sheet is then heat-treated in a non-oxidizing atmosphere at 600.degree. to 1200.degree. C. for 0.01 to 20 hours, so that the mean grain size of 0.2 mm or smaller can be obtained.

Magnetic head alloy material and method of producing the same

A method of heat-treating an amorphous material as that the amorphous material has a high magnetic permeability, is disclosed in which an amorphous material having a Curie temperature T.sub.c higher than or equal to its crystallization temperature T.sub.x is held for a short time at a temperature T satisfying relations T.gtoreq.0.95 T.sub.c and T.gtoreq.T.sub.x.

Method of heat-treating amorphous material

A ferromagnetic amorphous alloy having a composition represented by (Co.sub.x Ni.sub.y Fe.sub.z).sub.a M.sub.b G.sub.c, wherein M is Cr, Mo and/or W, G is Zr, Hf and/or Ti and x, y, z and a, b, c are selected to meet the conditions of x=1-y-z, 0.ltoreq.y.ltoreq.0.2, 0.ltoreq.z.ltoreq.0.7, a=1-b-c, 0.ltoreq.b.ltoreq.0.05 and 0.05.ltoreq.c.ltoreq.0.2 This amorphous alloy has a superior magnetic characteristic and a high thermal stability.

Growing community of inventors

Saitama, Japan

Yoshizo Sawada