Preparation method of high-toughness composite magnet

Abstract

The invention discloses a preparation method of a high-toughness composite magnet, and belongs to the technical field of magnetic materials. The preparation method comprises the steps that SmCo5-x-y-zCuxZryMoz and Fe51Co49-a-bCuaNib ribbon alloys are prepared through a melt rapid quenching method, the SmCo5-x-y-zCuxZryMoz and Fe51Co49-a-bCuaNib ribbon alloys are mixed according to a certain mass ratio and then sequentially put into a hot-pressing mold layer by layer to be stacked, and subsequent pressing forming and high-pressure torsion heat treatment are matched, so that the magnetic coupling effect of a hard magnetic phase and a soft magnetic phase is effectively promoted, and the magnetic coupling effect of the hard magnetic phase and the soft magnetic phase is effectively improved; and by adding trace nickel elements and molybdenum elements, the toughness of the composite magnet is improved, so that the composite magnet has relatively high impact strength and crack propagation resistance, and the final high-toughness composite magnet is obtained. The method is simple in technological process, easy to operate and beneficial to application of the high-toughness composite magnet in more permanent magnet devices so as to meet market requirements.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic materials, and in particular to a method for preparing a high-toughness composite magnet. Background Art

[0002] As a medium for converting electrical energy into mechanical energy, rare earth permanent magnet materials are currently widely used as core components in new energy fields such as wind power generation and electric vehicles due to their excellent magnetic properties. At the same time, rare earth permanent magnet SmCo5 alloy has the highest magnetocrystalline anisotropy (K1≈15~19×10 3 kJ / m 3 ), saturation magnetization M s : 0.59 T, Curie temperature T c : 740℃, its theoretical magnetic energy product reaches 224.9 kJ / m 3 However, Sm-Co rare earth permanent magnets have poor toughness due to their intermetallic compound structure, which is complex and has few slip systems. For example, the bending strength of the traditional 2:17 sintered samarium cobalt alloy is only 80~140 MPa, and the fracture toughness is 1.5~2.5 MPa, which is comparable to the fracture toughness value of ceramic materials, making it difficult for samarium cobalt magnets to serve safely in special vibration environments.

[0003] To this end, the present invention discloses a method for preparing a high-toughness composite magnet. 5-x-y-z Cu x Zr y Mo z and Fe 51 Co 49-a-b Cu a Ni b The thin strip alloy is mixed according to a certain mass ratio and then placed layer by layer in a hot pressing mold for stacking, and is matched with subsequent pressing and high-pressure torsion heat treatment, which effectively promotes the magnetic coupling of the hard magnetic phase and the soft magnetic phase. The addition of trace nickel and molybdenum elements improves the toughness of the composite magnet, making it have higher impact strength and crack propagation resistance, and finally obtains a high-toughness SmCo / FeCo composite magnet. The invention simplifies the process, is easy to operate, has low cost, and is suitable for large-scale batch production. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention aims to provide a method for preparing a high-toughness composite magnet.

[0005] The method for preparing the high-toughness composite magnet of the present invention comprises the following steps: (1) Using vacuum induction melting technology to prepare SmCo5-x-y-z Cu x Zr y Mo z Hard magnet and Fe 51 Co 49-a- b Cu a Ni b A soft magnetic alloy ingot, wherein 0.1≤x≤1.2, 0.02≤y≤0.08, 0.02≤z≤0.08, 0.05≤a≤0.5, 0.05≤b≤0.5; then SmCo is prepared by melt quenching method 5-x-y-z Cu x Zr y Mo z and Fe 51 Co 49-a-b Cu a Ni b The thin strip alloy is selected with a width of 3-5 mm and a length of 50-80 mm, and the copper roller speed is 10-60 m / s; (2) The SmCo obtained in step (1) 5-x-y-z Cu x Zr y Mo z and Fe 51 Co 49-a-b Cu a Ni b After the thin strip alloys are mixed in a mass ratio of 1:0.1-0.3, the thin strip alloys are placed layer by layer in a hot pressing mold for stacking, and then pressed into shape; (3) The pressed magnet obtained in step (2) is subjected to high pressure torsion heat treatment to obtain a final high-toughness composite magnet.

[0006] Furthermore, the temperature of the hot pressing molding in step (2) is 600-800°C, the pressure is 300-500 MPa, and the pressing time is 5-15 min.

[0007] Furthermore, the temperature of the high-pressure torsion heat treatment described in step (3) is 750~1000°C, the pressure is 100~200 MPa, the heat treatment time is 100~200 min, the number of torsion turns is 3~6 turns, and the torsion rate is 10° / min.

[0008] Compared with the existing technology, the present invention has the following advantages and beneficial effects: the present invention effectively compounds the hard magnetic SmCo5 thin strip alloy and the soft magnetic Fe-Co-Cu-Ni thin strip alloy, and directly puts two thin strip alloys within a certain size range into a hot pressing mold for stacking and pressing, thereby eliminating the ball milling process in the traditional preparation process, simplifying the process flow, and adding trace nickel and molybdenum elements to improve the toughness of the composite magnet, so that it has higher impact strength and crack propagation resistance; at the same time, the introduction of high-pressure torsion heat treatment causes the block magnet to produce high-density defects (such as vacancies, dislocations and stacking faults), improves the texture orientation and magnetic anisotropy of the magnet, and finally obtains a composite magnet with high toughness and high magnetic properties. In addition, the method of the present invention has a simple process, low process cost, low energy consumption, and is suitable for mass production. DETAILED DESCRIPTION

[0009] The present invention will be further described in detail below with reference to the embodiments, but the present invention is not limited to the following embodiments.

[0010] Example 1 (1) Using vacuum induction melting technology to prepare SmCo 4.8 Cu 0.1 Zr 0.02 Mo 0.08 Hard magnet and Fe 51 Co 48.45 Cu 0.5 Ni 0.05 The soft magnetic alloy ingot is then melt-quenched to prepare SmCo 4.8 Cu 0.1 Zr 0.02 Mo 0.08 and Fe 51 Co 48.45 Cu 0.5 Ni 0.05 The thin strip alloy is selected with a width of 3 mm and a length of 60 mm, and the copper roller speed is 10 m / s; (2) The SmCo obtained in step (1) 4.8 Cu 0.1 Zr 0.02 Mo 0.08 and Fe 51 Co 48.45 Cu 0.5 Ni 0.05 After the thin strip alloys are mixed in a mass ratio of 1:0.1, the thin strip alloys are placed layer by layer in a hot pressing mold for stacking, and then pressed into shape. The hot pressing molding temperature is 600°C, the pressure is 300 MPa, and the pressing time is 15 min. (3) The pressed magnet obtained in step (2) is subjected to high-pressure torsion heat treatment, wherein the temperature of the high-pressure torsion heat treatment is 800°C, the pressure is 100 MPa, the heat treatment time is 100 min, the number of torsion turns is 3 turns, and the torsion rate is 10° / min, to obtain a final high-toughness composite magnet.

[0011] The composite magnet prepared by the present invention is tested for magnetic properties and fracture toughness, and the coercive force is 12.5 kOe, the magnetic energy product is 11.9 MGOe, and the fracture toughness is 18.3 MN·m -3 / 2 .

[0012] Example 2 (1) Using vacuum induction melting technology to prepare SmCo 4.4 Cu 0.5 Zr 0.04 Mo 0.06 Hard magnet and Fe 51 Co 48.5 Cu 0.3 Ni 0.2 The soft magnetic alloy ingot is then melt-quenched to prepare SmCo 4.4 Cu 0.5 Zr 0.04 Mo 0.06 and Fe 51 Co 48.5 Cu 0.3 Ni 0.2 The thin strip alloy was selected with a width of 4 mm and a length of 70 mm, and the copper roller speed was 30 m / s; (2) The SmCo obtained in step (1) 4.4 Cu 0.5 Zr 0.04 Mo 0.06 and Fe 51 Co 48.5 Cu 0.3 Ni 0.2 After the thin strip alloys are mixed in a mass ratio of 1:0.2, the thin strip alloys are placed layer by layer in a hot pressing mold for stacking, and then pressed into shape. The hot pressing molding temperature is 700°C, the pressure is 400 MPa, and the pressing time is 10 min. (3) The pressed magnet obtained in step (2) is subjected to high-pressure torsion heat treatment, wherein the temperature of the high-pressure torsion heat treatment is 900°C, the pressure is 150 MPa, the heat treatment time is 150 min, the number of torsion turns is 4 turns, and the torsion rate is 10° / min, to obtain a final high-toughness composite magnet.

[0013] The composite magnet prepared by the present invention is tested for magnetic properties and fracture toughness, and the coercive force is 13.7 kOe, the magnetic energy product is 12.8 MGOe, and the fracture toughness is 19.4 MN·m -3 / 2 .

[0014] Example 3 (1) Using vacuum induction melting technology to prepare SmCo 3.69 Cu 1.2 Zr 0.08 Mo 0.03 Hard magnet and Fe 51 Co 48.3 Cu 0.2 Ni 0.5 The soft magnetic alloy ingot is then melt-quenched to prepare SmCo 3.69 Cu 1.2 Zr 0.08 Mo 0.03 and Fe 51 Co 48.3 Cu 0.2 Ni 0.5 The thin strip alloy is selected with a width of 5 mm and a length of 60 mm, and the copper roller speed is 50 m / s; (2) The SmCo obtained in step (1) 3.69 Cu 1.2 Zr 0.08 Mo 0.03 and Fe 51 Co 48.3 Cu 0.2 Ni 0.5 After the thin strip alloys are mixed in a mass ratio of 1:0.3, the thin strip alloys are placed layer by layer in a hot pressing mold for stacking, and then pressed into shape. The hot pressing molding is performed at a temperature of 800°C, a pressure of 500 MPa, and a pressing time of 5 min. (3) The pressed magnet obtained in step (2) is subjected to high-pressure torsion heat treatment, wherein the temperature of the high-pressure torsion heat treatment is 950°C, the pressure is 200 MPa, the heat treatment time is 200 min, the number of torsion turns is 6 turns, and the torsion rate is 10° / min, to obtain a final high-toughness composite magnet.

[0015] The composite magnet prepared by the present invention is tested for magnetic properties and fracture toughness, and the coercive force is 14.1 kOe, the magnetic energy product is 13.4 MGOe, and the fracture toughness is 21.1 MN·m -3 / 2 .

Claims

1. A method for preparing a high-toughness composite magnet, characterized in that The steps include: (1) Using vacuum induction melting technology to prepare SmCo 5-x-y-z Cu x Zr y Mo z Hard magnet and Fe 51 Co 49-a- b Cu a Ni b A soft magnetic alloy ingot, wherein 0.1≤x≤1.2, 0.02≤y≤0.08, 0.02≤z≤0.08, 0.05≤a≤0.5, 0.05≤b≤0.5; then SmCo is prepared by melt quenching method 5-x-y-z Cu x Zr y Mo z and Fe 51 Co 49-a-b Cu a Ni b The thin strip alloy is selected with a width of 3-5 mm and a length of 50-80 mm, and the copper roller speed is 10-60 m / s; (2) The SmCo obtained in step (1) 5-x-y-z Cu x Zr y Mo z and Fe 51 Co 49-a-b Cu a Ni b After the thin strip alloys are mixed in a mass ratio of 1:0.1-0.3, the thin strip alloys are placed layer by layer in a hot pressing mold for stacking, and then pressed into shape; (3) The pressed magnet obtained in step (2) is subjected to high pressure torsion heat treatment to obtain a final high-toughness composite magnet.

2. The method for preparing a high-toughness composite magnet according to claim 1, characterized in that: The temperature of the hot pressing molding described in step (2) is 600~800°C, the pressure is 300~500 MPa, and the pressing time is 5~15 min.

3. The method for preparing a high-toughness composite magnet according to claim 1, characterized in that: The temperature of the high-pressure torsion heat treatment described in step (3) is 750~1000°C, the pressure is 100~200 MPa, the heat treatment time is 100~200min, the number of torsion turns is 3~6 turns, and the torsion rate is 10° / min.