Alloy target material, method of manufacturing the same, use thereof, and method of processing a neodymium-iron-boron magnet

Abstract

The application discloses an alloy target material and a preparation method and application thereof, and a processing method of a neodymium-iron-boron magnet. The alloy target material is composed of 50-80wt% Al, 5-20wt% Mn and 4-35wt% rare earth elements. The alloy target material is not easy to be broken in a magnetron sputtering coating process.

Description

Technical Field

[0001] This invention relates to an alloy target material, its preparation method and uses, and also to a method for processing neodymium iron boron magnets. Background Technology

[0002] The main methods for preparing protective layers for NdFeB magnets on an industrial scale include electroplating and electroless plating. During the preparation of the protective coating, plating solution residue can occur, leading to a decrease in the magnetic properties of the magnet and affecting the product yield. Furthermore, the discharge of plating solution causes significant environmental pollution. Vacuum coating technology, which eliminates raw material spillage and pollutant emissions during the coating process and produces a strong protective film adhesion, has attracted widespread attention in the field of NdFeB magnet surface protection. Currently, vacuum coating of NdFeB magnet surface protective layers mainly focuses on aluminum coatings. While aluminum coatings improve resistance to fume corrosion, they have relatively low hardness. Adding Mn to the aluminum coating can form an Al-Mn amorphous coating, but a high Mn content is required to achieve this amorphous structure. For example, CN106835033A discloses a high-manganese-content aluminum-manganese alloy target composed of 50–75 wt% aluminum and 25–50 wt% manganese. The target material contains 25-50 wt% manganese, which increases the brittleness of the alloy, causing the Al-Mn coated sputtering source target material to crack and fall off, rendering it unusable.

[0003] CN109252142A discloses an aluminum-scandium alloy target blank, wherein the volume percentage of secondary precipitates is 5-25%, the uniform size is 20-45 μm, and the shape is polygonal and near-spherical. In the secondary precipitates, the volume percentage of agglomerates is <30%, and the volume percentage of near-spherical particles is >60%. CN111455223B discloses a method for preparing an aluminum-scandium alloy target, comprising a scandium mass percentage of 5-40% and an aluminum mass percentage of 60-95%. After melting the scandium, aluminum is repeatedly added to the scandium, and the mixture is repeatedly smelted to obtain the desired aluminum-scandium alloy. CN116083862A discloses an aluminum-scandium alloy sputtering target, comprising aluminum and scandium. The scandium atomic percentage in the aluminum-scandium alloy sputtering target is ≥0.01% and less than 3.5%, with the remainder being aluminum. The aforementioned target materials are used for coating electronic components such as signal processing and control circuits, sensors, actuators, LCD panels, and light-emitting diodes.

[0004] CN110468312A discloses a corrosion-resistant aluminum alloy target for photovoltaic reflective films, comprising aluminum, transition metal element M, and rare earth element N, wherein the aluminum content is ≥75wt%, the content of transition metal element M is 1-15wt%, and the content of rare earth element N is 1-10wt%. This alloy target cannot achieve an amorphous structure. Summary of the Invention

[0005] In view of this, one object of the present invention is to provide an alloy target that is not easily broken during magnetron sputtering coating. Furthermore, the alloy target has high purity and low elemental deviation. Even further, the coating formed by the alloy target has high hardness and corrosion resistance, and the coating has high adhesion to the neodymium iron boron magnet.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned alloy target. This method can improve the purity of the alloy target and reduce elemental deviation.

[0007] Another object of the present invention is to provide an application of an alloy target material.

[0008] Another object of the present invention is to provide a method for processing neodymium iron boron magnets, which can improve the bonding force between the neodymium iron boron substrate and the coating, and the resulting coating has high hardness and can improve the corrosion resistance of the neodymium iron boron magnets.

[0009] The above objectives are achieved through the following technical solutions.

[0010] On one hand, the present invention provides an alloy target material composed of 50-76 wt% Al, 5-20 wt% Mn and 4-35 wt% rare earth elements.

[0011] According to the alloy target material of the present invention, preferably, the total content of Al, Mn and rare earth elements in the alloy target material is ≥99.5wt%, the Al content deviation is ≤5%, the Mn content deviation is ≤5%, and the rare earth element content deviation is ≤5%.

[0012] On the other hand, the present invention provides a method for preparing the above-mentioned alloy target material, comprising the following steps:

[0013] (a) The raw materials are melted under an inert gas atmosphere and at a pressure of 0.02 to 0.08 MPa, and then refined to obtain an alloy liquid;

[0014] (b) The alloy liquid is cast and then milled to obtain the alloy target material.

[0015] According to the preparation method of the present invention, preferably, the smelting power is 20-30kW and the smelting time is 10-20min; the refining power is 10-20kW and the refining time is 1-5min; and the casting power is 5-12kW.

[0016] In another aspect, the present invention provides the use of the above-mentioned alloy target material in vacuum coating of neodymium iron boron magnets.

[0017] In another aspect, the present invention provides a method for processing neodymium iron boron magnets, comprising the following steps:

[0018] (1) Using an aluminum target as a sputtering source, a transition layer is formed on a neodymium iron boron substrate by magnetron sputtering to obtain the first intermediate;

[0019] (2) Using an aluminum target and the above-mentioned alloy target as sputtering sources, a gradient layer is formed on the first intermediate by magnetron sputtering to obtain the second intermediate.

[0020] (3) Using the above alloy target as a sputtering source, an amorphous layer is formed on the second intermediate by magnetron sputtering.

[0021] According to the processing method of the present invention, preferably, in step (1), the power density of the aluminum target is 10-15 W / cm². 2 The workpiece bias voltage is 100-200V, and the coating time is 3-8 minutes.

[0022] In step (2), the power density of the aluminum target is 10–15 W / cm². 2 The workpiece bias voltage is 100–200V, and the alloy target power density is 15–25W / cm³. 2 The coating time is 2 to 7 minutes;

[0023] In step (3), the workpiece bias voltage is 60–120V, and the alloy target power density is 15–25W / cm². 2 The coating time is 20 to 60 minutes.

[0024] According to the processing method of the present invention, preferably, steps (1) to (3) are carried out under a pressure of 0.3 to 1.0 Pa and in the presence of argon.

[0025] According to the processing method of the present invention, preferably, after the amorphous layer is formed, the NdFeB substrate having the amorphous layer is cooled to 25-35°C in the furnace to obtain the coated NdFeB magnet.

[0026] According to the processing method of the present invention, preferably, the neodymium iron boron substrate, aluminum target and alloy target are cleaned before magnetron sputtering coating.

[0027] The alloy target of this invention is not easily broken during magnetron sputtering coating. This alloy target can form a coating with high hardness on the surface of NdFeB magnets, and the coating has high adhesion to the NdFeB magnets, thus improving the corrosion resistance of the NdFeB magnets. The processing method of this invention can further improve the above-mentioned properties. Attached Figure Description

[0028] Figure 1 This is a photograph of the alloy target material after use in Example 4.

[0029] Figure 2The images show the XRD patterns of the amorphous layers of the NdFeB magnets after coating, as formed in Examples 4-6.

[0030] Figure 3 This is a SEM image of the amorphous layer of the NdFeB magnet after coating in Example 4.

[0031] Figure 4 This is a SEM image of the amorphous layer of the NdFeB magnet after coating in Example 5.

[0032] Figure 5 This is a SEM image of the amorphous layer of the NdFeB magnet after coating in Example 6.

[0033] Figure 6 This is a photograph of the alloy target material in Comparative Example 2 after use. Detailed Implementation

[0034] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0035] <Alloy Sputtering Material>

[0036] The alloy target material of this invention is composed of 50-76 wt% Al, 5-20 wt% Mn, and 4-35 wt% rare earth elements. Of course, the alloy target material may also contain some unavoidable impurity elements. Impurity elements include, but are not limited to, C, N, O, S, Na, Mg, Si, K, Ca, Fe, Ni, Cu, and Ta. The content of impurity elements is less than or equal to 0.5 wt%; preferably, less than or equal to 0.2 wt%. The low Mn content in the alloy target material of this invention avoids cracking and detachment during use, improving film formation efficiency and quality. Adding an appropriate amount of rare earth elements enables the formation of an amorphous film on the surface of a NdFeB magnet under conditions of low Mn content, resulting in a refined, uniform amorphous structure with few internal pores.

[0037] The rare earth elements of this invention can be selected from one or more of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, and Sc. Preferably, the rare earth elements are selected from one or more of Ce, La, and Nd. When the rare earth elements are selected from Ce, La, and Nd, they can form a protective film of superior quality on the surface of the NdFeB magnet.

[0038] The rare earth element content is 4–35 wt%; preferably 12–25 wt%; more preferably 15–18 wt%. This allows for the formation of a high-quality amorphous protective film with low manganese content, while also ensuring the film has high hardness and corrosion resistance.

[0039] The Mn content is 5–20 wt%; preferably 8–18 wt%; more preferably 15–17 wt%. This can reduce the breakage rate of the alloy target material during use and can form a high-quality amorphous film.

[0040] The Al content is 50–76 wt%; preferably 63–70 wt%; more preferably 66–68 wt%.

[0041] This invention controls the amount of each element within the above-mentioned range, which can reduce the breakage rate of the alloy target material during use and form an amorphous film on the surface of the NdFeB alloy. The formed protective film has high hardness and corrosion resistance.

[0042] In the alloy target material of the present invention, the total content of Al, Mn and rare earth elements is ≥99.5wt%; preferably, the total content of Al, Mn and rare earth elements is ≥99.8wt%.

[0043] In the alloy target material of the present invention, the Al content deviation is ≤5%; preferably, the Al content deviation is ≤3%; more preferably, the Al content deviation is ≤2%.

[0044] In the alloy target material of the present invention, the Mn content deviation is ≤5%; preferably, the Mn content deviation is ≤4.5%.

[0045] In the alloy target material of the present invention, the rare earth element content deviation is ≤5%; preferably, the rare earth element content deviation is ≤4%.

[0046] <Preparation Method of Alloy Targets>

[0047] The method for preparing the alloy target of the present invention includes the following steps: (a) melting and refining; and (b) forming and processing.

[0048] The steps of smelting and refining

[0049] The raw materials are melted under inert gas protection and at a pressure of 0.02 to 0.08 MPa, and then refined to obtain an alloy liquid.

[0050] The raw materials can be determined based on the chemical composition of the alloy target.

[0051] During smelting, the raw materials can be placed in the smelting furnace from bottom to top in the order of Mn, rare earth metals, and Al.

[0052] The inert gas can be selected from one or more of helium, neon, and argon. According to one embodiment of the present invention, the inert gas is argon.

[0053] The smelting can be carried out at a pressure of 0.02 to 0.08 MPa. Preferably, it is carried out at a pressure of 0.04 to 0.06 MPa.

[0054] The smelting power can be 20 to 30 kW; preferably 23 to 27 kW.

[0055] The melting time can be 10 to 20 minutes; preferably 12 to 15 minutes.

[0056] The refining power can be 10 to 20 kW; preferably 13 to 17 kW.

[0057] The refining time can be 1 to 5 minutes; preferably 2 to 4 minutes.

[0058] Molding and processing steps

[0059] The alloy liquid is poured into a casting, and then milled to obtain the alloy target material.

[0060] The casting power can be 5 to 12 kW; preferably 7 to 9 kW.

[0061] <Applications of Alloy Sputters>

[0062] The alloy target material of this invention can form a smooth, dense amorphous protective film on the surface of NdFeB magnets, exhibiting high hardness and corrosion resistance. Therefore, this invention provides the application of the aforementioned alloy target material in vacuum coating of NdFeB magnets.

[0063] <Methods for processing neodymium iron boron magnets>

[0064] The method for processing NdFeB magnets according to the present invention includes the following steps: (1) forming a transition layer; (2) forming a gradient layer; and (3) forming an amorphous layer. In some embodiments, it further includes a pretreatment step of the NdFeB substrate and the target material. This can improve the adhesion between the coating and the substrate, improve the corrosion resistance of the NdFeB magnet, and the formed coating has high hardness.

[0065] Steps to form a transition layer

[0066] Using an aluminum target as the sputtering source, a transition layer is formed on a neodymium iron boron substrate by magnetron sputtering to obtain the first intermediate.

[0067] The power density of aluminum targets can be 10–15 W / cm². 2 The preferred value is 12-13 W / cm². 2 .

[0068] The workpiece bias voltage can be 100-200V; preferably 130-170V.

[0069] The coating time can be 3 to 8 minutes; preferably 4 to 6 minutes.

[0070] This step is performed in the presence of argon gas.

[0071] This step is carried out at a pressure of 0.3 to 1.0 Pa; preferably 0.5 to 0.8 Pa.

[0072] The neodymium iron boron matrix includes Nd, B, and Fe. In some embodiments, it may also include one or more of Pr, Ga, Co, Nb, Al, and Cu.

[0073] The Nd content can be 10–30 wt%; preferably 15–25 wt%.

[0074] The content of B can be 0.1–3 wt%; preferably 0.5–1.5 wt%.

[0075] The Fe content can be 55-80 wt%; preferably 60-75 wt%.

[0076] The content of Pr can be 2 to 10 wt%; preferably 4 to 8 wt%.

[0077] The Ga content can be 0.05–0.5 wt%; preferably 0.1–0.3 wt%.

[0078] The Co content can be 0.1–1.5 wt%; preferably 0.3–1 wt%.

[0079] The Nb content can be 0.05–0.5 wt%; preferably 0.1–0.3 wt%.

[0080] The Al content can be 0.01 to 0.2 wt%; preferably 0.05 to 0.15 wt%.

[0081] The Cu content can be 0.01–0.2 wt%; preferably 0.05–0.15 wt%.

[0082] Steps to form a gradient layer

[0083] A gradient layer was formed on the first intermediate using magnetron sputtering with aluminum and alloy targets as sputtering sources to obtain the second intermediate. The alloy targets were described in detail above and will not be repeated here.

[0084] The power density of aluminum targets can be 10–15 W / cm². 2 The preferred value is 12-13 W / cm². 2 .

[0085] The power density of the alloy target material can be 15–25 W / cm³. 2 The preferred strength is 18–22 W / cm². 2 .

[0086] The workpiece bias voltage can be 100-200V; preferably 130-170V.

[0087] The coating time can be 2 to 7 minutes; preferably 4 to 6 minutes.

[0088] This step is performed in the presence of argon gas.

[0089] This step is carried out at a pressure of 0.3 to 1.0 Pa; preferably 0.5 to 0.8 Pa.

[0090] Steps for forming an amorphous layer

[0091] Using an alloy target as the sputtering source, an amorphous layer is formed on the second intermediate by magnetron sputtering. The alloy target has been described in detail above and will not be repeated here.

[0092] The power density of the alloy target material can be 15–25 W / cm³. 2 The preferred strength is 18–22 W / cm². 2 .

[0093] The workpiece bias voltage can be 60–120V; preferably 80–110V.

[0094] The coating time can be 20 to 60 minutes; preferably 30 to 50 minutes.

[0095] This step is performed in the presence of argon gas.

[0096] This step is carried out at a pressure of 0.3 to 1.0 Pa; preferably 0.5 to 0.8 Pa.

[0097] After the amorphous layer is formed, the argon gas supply is stopped and the turbomolecular pump is turned off. After the furnace temperature cools to 25-35°C, all vacuum pumps are turned off, the gas is released and the furnace is removed to obtain the coated NdFeB magnet.

[0098] Preprocessing steps

[0099] The surface of the NdFeB substrate can be cleaned before use. For example, ion cleaning can be used. Cleaning can be performed in the presence of argon gas. Cleaning can be performed at a pressure of 0.5–2 Pa; preferably 0.8–1.2 Pa. The ion source current of the anode layer can be 3–10 A; preferably 5–8 A. The workpiece bias voltage can be 180–250 V; preferably 200–230 V. The cleaning time can be 15–45 min; preferably 25–35 min.

[0100] Aluminum and / or alloy targets can be cleaned before use. Cleaning can be performed in a magnetron sputtering coating machine. Cleaning can be performed in the presence of argon gas at a pressure of 0.3–1.5 Pa; preferably 0.5–1.0 Pa. The target power density can be 15–25 W / cm³. 2 The preferred strength is 18–22 W / cm². 2 The cleaning time can be 5 to 30 minutes; preferably 10 to 20 minutes.

[0101] The testing method is described below:

[0102] Purity of the alloy target: The purity of the alloy target was tested using glow discharge mass spectrometry. The impurity elements detected were C, N, O, S, Na, Mg, Si, K, Ca, Fe, Ni, Cu, and Ta.

[0103] Deviations of elements in the alloy target: The deviations of elements in the alloy target were tested using an atomic emission spectrometer.

[0104] Adhesion: The adhesion between the coating and the NdFeB substrate was tested using a multifunctional material surface performance tester. A scratch test was conducted with a linear scratch speed of 10 mm / min, a loading speed of 100 N / min, a test load of 0–80 N, and a scratch length of 8 mm.

[0105] Hardness: The hardness of the coating on the NdFeB substrate surface was tested using a microhardness tester. The loading force was 100 gf, and the loading time was 10 s.

[0106] Self-corrosion current density: The potentiodynamic polarization of the coated NdFeB magnet was tested using an electrochemical workstation. The tested polarization curves were fitted using the Tafel extrapolation method to determine the self-corrosion current density.

[0107] Neutral salt spray corrosion time: The neutral salt spray corrosion time of the coated NdFeB magnets was tested using a neutral salt spray test chamber. The corrosion solution used was a 5% ± 1% (mass fraction) NaCl solution.

[0108] The raw materials are described below:

[0109] The chemical composition of the NdFeB matrix is ​​as follows:

[0110] Pr: 6.42wt%, Nd: 22.62wt%, Ga: 0.18wt%, Co: 0.52wt%, Nb: 0.21wt%, Al: 0.09wt%, Cu: 0.09wt%, B: 0.9wt%, Fe: balance.

[0111] Examples 1-3

[0112] The raw materials are provided according to the composition of the alloy target shown in Table 1. Metallic manganese, rare earth metals, and metallic aluminum are placed sequentially from bottom to top in a vacuum induction melting furnace. When the pressure inside the melting furnace is below 2 × 10⁻⁶... -1 Argon gas was introduced into the melting furnace at a pressure of 0.06 MPa to begin melting, followed by refining to obtain a molten alloy. The melting power was 25 kW, and the melting time was 12 min. The refining power was 15 kW, and the refining time was 3 min.

[0113] The molten alloy was poured to obtain an alloy ingot. The pouring power was 8 kW. The alloy ingot was then milled and turned to obtain an alloy target.

[0114] The purity and the deviation of each element of the obtained alloy target are shown in Table 2.

[0115] Table 1

[0116] Al (wt%) Mn(wt%) Ce (wt%) La (wt%) Nd(wt%) Example 1 67.6 16.0 16.4 — — Example 2 64.4 12.2 — 23.4 — Example 3 67.0 9.3 — — 23.7

[0117] Note: The content of each element in the table above is calculated based on the total content of Al, Mn and rare earth elements.

[0118] Table 2

[0119]

[0120] Comparative Example 1

[0121] Raw materials are provided according to the composition of the alloy target. Metallic manganese and metallic aluminum are placed sequentially from bottom to top in a vacuum induction melting furnace. When the pressure inside the melting furnace is below 2 × 10⁻⁶... -1 Argon gas was introduced into the melting furnace at a pressure of 0.06 MPa to begin melting, followed by refining to obtain a molten alloy. The melting power was 25 kW, and the melting time was 12 min. The refining power was 15 kW, and the refining time was 3 min.

[0122] The molten alloy was poured to obtain an alloy ingot. The pouring power was 8 kW. The alloy ingot was then milled to obtain an alloy sputtering target. The alloy sputtering target consisted of 70 wt% Al and 30 wt% Mn.

[0123] Examples 4-6

[0124] The NdFeB substrate is mounted on the workpiece holder and then pushed into the vacuum chamber. The furnace door is closed, and the mechanical pump-Roots pump unit is started. Once the pressure reaches 5 Pa, the turbomolecular pump and its forestage holding pump are started to begin evacuating the back-bottom vacuum. When the pressure reaches 5 × 10⁻⁶ Pa... -3After Pa, rotate the workpiece holder, introduce argon gas, and adjust the argon gas flow rate to maintain the pressure at 1.0 Pa. Turn on the anode layer ion source, set the anode layer ion source current to 6A, and the workpiece bias voltage to 220V. After ion cleaning the NdFeB substrate for 30 minutes, turn off the anode layer ion source to obtain the treated NdFeB substrate.

[0125] Adjust the argon gas flow rate to maintain the pressure at 0.7 Pa. Clean the aluminum and alloy targets located at the cathode targets, respectively. Set the target power density of the aluminum and alloy targets to 20 W / cm². 2 The cleaning time is 15 minutes, and the treated target material is obtained.

[0126] Using a treated aluminum target as the sputtering source, a transition layer was formed on the treated NdFeB substrate by magnetron sputtering in the presence of argon gas at a pressure of 0.7 Pa, thus obtaining the first intermediate. The aluminum target power density was 12 W / m². 2 The workpiece bias voltage is 150V, and the coating time is 5 minutes.

[0127] Using treated aluminum and alloy targets as sputtering sources, a gradient layer was formed on the first intermediate by magnetron sputtering in the presence of argon gas at a pressure of 0.7 Pa, thus obtaining the second intermediate. The aluminum target power density was 12 W / m³. 2 The workpiece bias voltage is 150V, and the alloy target power density is 20W / m². 2 The coating time is 5 minutes.

[0128] Using the treated alloy target as the sputtering source, an amorphous layer was formed on the second intermediate by magnetron sputtering in the presence of argon gas at a pressure of 0.7 Pa. The power density of the alloy target was 20 W / cm². 2 The workpiece bias voltage was 100V, and the coating time was 40 minutes. Argon gas supply was stopped, and the turbomolecular pump was turned off. After the furnace temperature cooled to 30°C, all vacuum pumps were turned off, the gas was released, and the coated NdFeB magnet was obtained.

[0129] The alloy targets used are shown in Table 3. The performance of the NdFeB magnets after coating is shown in Table 3.

[0130] Figure 1 This is a photograph of the alloy target material used in Example 4 after its application. Figure 1 As can be seen, the alloy target surface is intact, without cracks or detachment, and can be used normally. The alloy targets in Examples 5-6, after use, showed intact target surfaces without cracks or detachment, and can be used normally.

[0131] Figure 2 The images show the XRD patterns of the amorphous layers of the coated NdFeB magnets formed in Examples 4-6. Figure 2It can be seen that the amorphous layer has an amorphous structure.

[0132] Figure 3 This is a SEM image of the amorphous layer of the NdFeB magnet after coating in Example 4. Figure 4 This is a SEM image of the amorphous layer of the NdFeB magnet after coating in Example 5. Figure 5 This is a SEM image of the amorphous layer of the coated NdFeB magnet in Example 6. Figure 3-5 It can be seen that the amorphous layers in Examples 4-6 are flat and dense.

[0133] Example 7

[0134] The neodymium iron boron substrate and the alloy target were cleaned according to the method in Example 4 to obtain the treated neodymium iron boron substrate and the treated alloy target.

[0135] Using the treated alloy target as the sputtering source, an amorphous layer was formed on the treated NdFeB substrate by magnetron sputtering in the presence of argon gas at a pressure of 0.7 Pa. The power density of the alloy target was 20 W / cm². 2 The workpiece bias voltage was 100V, and the coating time was 40 minutes. Argon gas supply was stopped, and the turbomolecular pump was turned off. After the furnace temperature cooled to 30°C, all vacuum pumps were turned off, the gas was released, and the coated NdFeB magnet was obtained.

[0136] The alloy targets used are shown in Table 3. The performance of the NdFeB magnets after coating is shown in Table 3.

[0137] Table 3

[0138] Example 4 Example 5 Example 6 Example 7 Types of alloy sputtering targets Example 1 Example 2 Example 3 Example 1 Bonding force (N) between the coating and the NdFeB substrate 52 50 49 39 Hardness (HV) 510.5 472.6 485.9 475.2 <![CDATA[Self-corrosion current density (A / cm 2 )]]> <![CDATA[1.31×10 -8 ]]> <![CDATA[1.80×10 -8 ]]> <![CDATA[1.54×10 -8 ]]> <![CDATA[1.49×10 -8 ]]> Neutral salt spray corrosion time (h) 498 475 482 480

[0139] Comparative Example 2

[0140] Except for replacing the alloy target with the alloy target prepared in Comparative Example 1, the rest is the same as in Example 4.

[0141] Figure 6 This is a photograph of the alloy target material in Comparative Example 2 after use. Figure 6 It can be seen that the alloy target material cracked during the sputtering process and could not be used normally.

[0142] This invention is not limited to the above-described embodiments. Any modifications, improvements, or substitutions that can be conceived by those skilled in the art without departing from the essential content of this invention fall within the scope of this invention.

Claims

1. A method of treating a neodymium-iron-boron magnet, characterized by, The method comprises the following steps: (1) using aluminum target as sputtering source, forming transition layer on Nd-Fe-B substrate by magnetron sputtering to obtain first intermediate body; aluminum target power density is 10-15 W / cm 2 , workpiece bias is 100-200 V, and coating time is 3-8 min; (2) using copper target as sputtering source, forming transition layer on first intermediate body by magnetron sputtering to obtain second intermediate body; copper target power density is 10-15 W / cm 2 , workpiece bias is 100-200 V, and coating time is 3-8 min; (2) using aluminum target and alloy target material as sputtering source, forming gradient layer on the first intermediate body by magnetic sputtering coating to obtain the second intermediate body; aluminum target power density is 10-15 W / cm 2 , workpiece bias is 100-200 V, alloy target material power density is 15-25 W / cm 2 , coating time is 2-7 min; (3) using alloy target as sputtering source, forming amorphous layer on the second intermediate body by magnetic sputtering coating; workpiece bias is 60-120V, power density of alloy target is 15-25W / cm 2 , coating time is 20-60min; The alloy target is composed of 66-70wt% Al, 15-17wt% Mn and 15-18wt% Ce.

2. The treatment method according to claim 1, characterized in that, The steps (1)-(3) are carried out under the pressure of 0.3-1.0 Pa and in the presence of argon.

3. The treatment method of claim 1, wherein After the amorphous layer is formed, the neodymium-iron-boron base with the amorphous layer is cooled to 25-35℃ in the furnace to obtain the plated neodymium-iron-boron magnet.

4. The treatment method according to any one of claims 1 to 3, characterized in that, The neodymium-iron-boron base, the aluminum target and the alloy target are cleaned before magnetron sputtering plating.

5. The treatment method of claim 1, wherein The method further comprises the following steps: (a) smelting the raw materials under the protection of inert gas and under the pressure of 0.02-0.08 MPa, and then refining to obtain an alloy liquid; (b) casting the alloy liquid, and then processing by turning and milling to obtain the alloy target.

6. The treatment method according to claim 5, characterized in that, The smelting power is 20-30 kW, and the smelting time is 10-20 min; the refining power is 10-20 kW, and the refining time is 1-5 min; the casting power is 5-12 kW.

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