Matsushita Electric Industrial Co., Ltd.

Nobuyuki Kato

Yoichi Sakamoto

Isago Konno

Tadao Ohtani

Takao Kubo

Kiyoshi Kojima

Shigeru Kojima

Masaharu Tsukahara

Takashi Matsumoto

Hisashi Yoshimura

Sadao Yukimoto

Tadoa Ohtani

An inboard type magnetic system for an electrodynamic transducer which has a reduced height and magnetic flux leakage by making use of a manganese-aluminum-carbon system alloy magnet anisotropized by warm extrusion.

Inboard type magnetic system for electro-dynamic transducer

Anisotropic permanent magnets of Mn-Al-C polycrystalline alloy are produced by warm extrusion at a temperature of 530.degree. to 830.degree. C utilizing converging or tapered dies with lubricant interposed between the polycrystalline body and the converging die. With dies of rather small semiangles, alloys with improved magnetic properties with regard to (BH)max, and especially Br are obtained.

Method of making anisotropic permanent magnets of Mn-Al-C alloys

Magnetic alloys consisting of 68.0.about.73.0 weight % manganese, (1/10 Mn - 6.6).about.(1/3 Mn - 22.2) weight % carbon, the balance aluminum, which show wasp-waisted magnetic hysteresis loops with the ratio of the residual magnetization 4.pi.I.sub.r to the intensity of magnetization 4.pi.I.sub.10000 in a magnetic field of 10000 Oe, I.sub.r /I.sub.10000, falling 0.0.about.0.2.

Magnetic alloys having wasp-waisted magnetic hysteresis loop

An anisotropic permanent magnet of an Mn-Al-C alloy containing 68.0% to 73.0% by weight of manganese, (1/10Mn-6.6)% to (1/3Mn-22.2)% by weight of carbon, and the remainder aluminum, which alloy is rendered anisotropic by deforming it plastically at a temperature of 530.degree. to 830.degree. C. The permanent magnet has excellent mechanical characteristics and magnetic properties such that the (BH) max is above 4.8 .times. 10.sup.6 G.Oe up to about 9.2 .times. 10.sup.6 G.Oe in its bulk state.

Anisotropic permanent magnet of Mn-Al-C alloy

An anisotropic permanent magnet of an Mn-Al-C alloy containing 68.0% to 73.0% by weight of manganese, (1/10 Mn-6.6)% to (1/3 Mn-22.2)% by weight of carbon, and the remainder aluminum, which alloy is rendered anisotropic by deforming it plastically at a temperature of 530.degree.C to 830.degree.C. The permanent magnet has excellent mechanical characteristics and magnetic properties such that the (BH)max is above 4.8 .times. 10.sup.6 G.Oe up to about 9.2 .times. 10.sup.6 G.Oe in its bulk state.

Machinable anisotropic permanent magnets of Mn-Al-C alloys

A method of making isotropic Mn-Al-C alloy magnets which comprises the step of subjecting an alloy comprising 71.0% to 73.0% by weight of manganese, (1/10 Mn -- 6.6)% to (1/3 Mn -- 22.2)% by weight of carbon and the remainder aluminum to plastic deformation at a temperature of 550.degree.C to 780.degree.C. By utilizing this method, it is possible to obtain isotropic Mn-Al-C alloy magnets having excellent magnetic characteristics, i.e. (BH)max = 2.0 .times. 10.sup.6 G. Oe or more.

Growing community of inventors

Katano, Japan

Nobuyuki Kato