Matsushita Electric Industrial Co., Ltd.

Shigeru Kojima

Yoichi Sakamoto

Kiyoshi Kojima

Tadao Ohtani

Isago Konno

Nobuyuki Kato

Takao Kubo

Masaharu Tsukahara

Satoru Mitani

Akihiko Ibata

Tadoa Ohtani

There is provided a method of producing a manganese-aluminum-carbon alloy magnet, including the steps of preparing a polycrystalline Mn-Al-C alloy magnet having a specified direction of easy magnetization and subjecting the magnet to compressive working in that direction at a temperature of 550.degree. to 780.degree. C., the degree of said compressive working being equivalent to a logarithmic strain of .ltoreq.-0.1 and working in said step at least up to a logarithmic strain of -0.1 being free compression.

Method of making permanent magnet of Mn-Al-C alloy

A permanent magnetic alloy which is obtained by adding copper in amount of 0.5 to 6.2 wt% to the conventional Mn-Al-C alloy comprising 68.0 to 73.0 wt% of manganese, (1/10 Mn -- 6.6) to (1/3 Mn -- 22.2) wt% of carbon and the remainder aluminum and subjecting thus prepared alloy to warm plastic deformation in order to improve plasticity of the alloy.

Permanent magnetic Mn-Al-C alloy

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.

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Kyoto, Japan

Shigeru Kojima