Permanent magnet, as well as motor and electrical power generator using same

Abstract

A permanent magnet according to the embodiment is equipped with: a composition represented by the composition formula R(FepMqCurCo1-p-q-r)z (R is at least one element selected from among rare earth elements, M is at least one element selected from among Zr, Ti, and Hf, 0.3 ≤ p ≤ 0.4, 0.01 ≤ q ≤ 0.05, 0.01 ≤ r ≤ 0.1, and 7 ≤ r ≤ 8.5 (atom ratios)); and a structure that is provided with a cell phase comprising a Th2Zn17-type crystal phase, and a cell wall phase that exists so as to surround the cell phase. The average magnetization of the cell wall phase is less than or equal to 0.2 T.

Description

technical field

[0001] Embodiments of the present invention relate to permanent magnets and motors and generators using the permanent magnets. Background technique

[0002] Rare earth magnets such as Sm—Co magnets and Nd—Fe—B magnets are known as high-performance permanent magnets. When a permanent magnet is used in a motor of a hybrid electric vehicle (HEV) or an electric vehicle (EV), heat resistance is required for the permanent magnet. In electric motors for HEVs and EVs, permanent magnets in which a part of neodymium (Nd) of Nd—Fe—B magnets are replaced with dysprosium (Dy) are used to improve heat resistance. Since Dy is one of the rare elements, it is desirable not to use Dy in the permanent magnet. It is known that the Sm—Co-based magnet exhibits excellent heat resistance as a component system that does not use Dy because of its high Curie temperature.

[0003] It is expected that a motor or the like using Sm—Co-based magnets can achieve good operating characteris...

Examples

Embodiment 1

[0057] Each raw material was weighed and mixed at a predetermined ratio, and cast after high-frequency dissolution in an Ar gas atmosphere to produce an alloy ingot. The alloy ingot is coarsely pulverized and then finely pulverized by a jet mill to prepare an alloy powder. The alloy powder is press-molded in a magnetic field to produce a compression-molded body. The compression-molded body of the alloy powder was placed in a firing furnace, heated up to 1190° C. in an Ar atmosphere, and kept at this temperature for 3 hours for sintering. Next, after performing solution treatment by holding at 1140° C. for 10 hours, it was rapidly cooled to 990° C. at a cooling rate of −250° C. / min, and further cooled to room temperature.

[0058] Next, the temperature of the solution-treated sintered body was raised to 800° C., kept at this temperature for 60 hours, and subjected to aging treatment. The aging-treated sintered body was slowly cooled to 450°C at a rate of -0.3°C / min, kept at t...

Embodiment 2、3

[0064] Under the same conditions as in Example 1, sintered magnets having the compositions shown in Table 1 were produced. The Cu concentration distribution, coercive force, residual magnetization, and squareness ratio in the cell wall phase of the obtained sintered magnet were measured and evaluated in the same manner as in Example 1. The measurement results are shown in Table 3. In addition, from the measurement results of the Cu concentration distribution in the cell wall phase, it was confirmed that the sintered magnets of Examples 2 and 3 had a region where the Cu concentration exceeded 40 atomic % near the center of the cell wall phase, as in Example 1.

Embodiment 4

[0066] Each raw material was weighed and mixed at a predetermined ratio, and cast to produce an alloy ingot after high-frequency dissolution in an Ar gas atmosphere. The alloy ingot is coarsely pulverized, followed by fine pulverization with a jet mill to prepare alloy powder. The alloy powder is press-molded in a magnetic field to produce a compression-molded body. The compression-molded body of the alloy powder was placed in a firing furnace, heated up to 1180° C. in an Ar atmosphere, and kept at this temperature for 5 hours for sintering. Next, after performing solution treatment by holding at 1130° C. for 12 hours, it was rapidly cooled to 980° C. at a cooling rate of −300° C. / min, and further cooled to room temperature.

[0067] Next, the temperature of the sintered body after the solution treatment was raised to 790° C., maintained at this temperature for 80 hours, and subjected to aging treatment. The aging-treated sintered body was slowly cooled to 480°C at a rate of...

technical field

[0001] Embodiments of the present invention relate to permanent magnets and motors and generators using the permanent magnets. Background technique

[0002] Rare earth magnets such as Sm—Co magnets and Nd—Fe—B magnets are known as high-performance permanent magnets. When a permanent magnet is used in a motor of a hybrid electric vehicle (HEV) or an electric vehicle (EV), heat resistance is required for the permanent magnet. In electric motors for HEVs and EVs, permanent magnets in which a part of neodymium (Nd) of Nd—Fe—B magnets are replaced with dysprosium (Dy) are used to improve heat resistance. Since Dy is one of the rare elements, it is desirable not to use Dy in the permanent magnet. It is known that the Sm—Co-based magnet exhibits excellent heat resistance as a component system that does not use Dy because of its high Curie temperature.

[0003] It is expected that a motor or the like using Sm—Co-based magnets can achieve good operating characteris...

Examples

Embodiment 1

[0057] Each raw material was weighed and mixed at a predetermined ratio, and cast after high-frequency dissolution in an Ar gas atmosphere to produce an alloy ingot. The alloy ingot is coarsely pulverized and then finely pulverized by a jet mill to prepare an alloy powder. The alloy powder is press-molded in a magnetic field to produce a compression-molded body. The compression-molded body of the alloy powder was placed in a firing furnace, heated up to 1190° C. in an Ar atmosphere, and kept at this temperature for 3 hours for sintering. Next, after performing solution treatment by holding at 1140° C. for 10 hours, it was rapidly cooled to 990° C. at a cooling rate of −250° C. / min, and further cooled to room temperature.

[0058] Next, the temperature of the solution-treated sintered body was raised to 800° C., kept at this temperature for 60 hours, and subjected to aging treatment. The aging-treated sintered body was slowly cooled to 450°C at a rate of -0.3°C / min, kept at t...

Embodiment 2、3

[0064] Under the same conditions as in Example 1, sintered magnets having the compositions shown in Table 1 were produced. The Cu concentration distribution, coercive force, residual magnetization, and squareness ratio in the cell wall phase of the obtained sintered magnet were measured and evaluated in the same manner as in Example 1. The measurement results are shown in Table 3. In addition, from the measurement results of the Cu concentration distribution in the cell wall phase, it was confirmed that the sintered magnets of Examples 2 and 3 had a region where the Cu concentration exceeded 40 atomic % near the center of the cell wall phase, as in Example 1.

Embodiment 4

[0066] Each raw material was weighed and mixed at a predetermined ratio, and cast to produce an alloy ingot after high-frequency dissolution in an Ar gas atmosphere. The alloy ingot is coarsely pulverized, followed by fine pulverization with a jet mill to prepare alloy powder. The alloy powder is press-molded in a magnetic field to produce a compression-molded body. The compression-molded body of the alloy powder was placed in a firing furnace, heated up to 1180° C. in an Ar atmosphere, and kept at this temperature for 5 hours for sintering. Next, after performing solution treatment by holding at 1130° C. for 12 hours, it was rapidly cooled to 980° C. at a cooling rate of −300° C. / min, and further cooled to room temperature.

[0067] Next, the temperature of the sintered body after the solution treatment was raised to 790° C., maintained at this temperature for 80 hours, and subjected to aging treatment. The aging-treated sintered body was slowly cooled to 480°C at a rate of...

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