Magnet pickling treatment method and magnet pickling treatment device

Abstract

The invention belongs to the technical field of magnet manufacturing, and discloses a magnet pickling treatment method and a magnet pickling treatment device. The magnet pickling treatment method comprises the steps that a magnet base material is installed on a hanging tool, the hanging tool is installed above a pickling tank, and the magnet base material is soaked in the pickling tank; the rack and / or the pickling tank are / is driven to move, so that the magnet base material can do reciprocating motion relative to a pickling solution in the pickling tank in the first direction and the second direction which form an included angle, and in the cycle of reciprocating motion in the second direction, the duration of motion towards the liquid level close to the pickling solution is smaller than the duration of motion towards the liquid level away from the pickling solution; and thus, the magnet base material can strike the pickling solution. By means of the magnet acid pickling treatment method, the problems of dust hanging and easy gas gathering can be solved, it can be guaranteed that the consistency of the acid pickling amount between batch magnet base materials is high, the acid pickling amount of each part of the single magnet base material in the circumferential direction is consistent, and the acid pickling effect of the single magnet base material is good.

Description

Technical Field

[0001] The invention relates to the technical field of magnet manufacturing, and in particular to a magnet pickling treatment method and a magnet pickling treatment device. Background Art

[0002] NdFeB magnetic material is a product formed by powder metallurgy sintering. It has the characteristics of loose structure, high porosity, poor surface condition and high brittleness. Therefore, it is very difficult to pickle NdFeB. NdFeB permanent magnet material has extremely high temperature and humidity requirements for the storage environment. The storage time should not be too long, otherwise the outermost neodymium-rich phase is easily oxidized and hydrogen-absorbed powdered, resulting in poor corrosion resistance. The surface of the black sheet is seriously rusted, and after processing, the surface of the black sheet is usually covered with oxide scale, and there will be burrs and burrs on the edge of the black sheet. Nitric acid, as a strong oxidizing acid, has an excellent corrosion effect on the edge and has a large damage to the macroscopic size of the magnet. It is suitable as a pickling medium for NdFeB materials. In the pre-treatment process of NdFeB, nitric acid pickling is one of the most critical processes. The most important purpose is to remove the oxide scale of the product and control the tolerance size of the product. Nitric acid can remove the oxide film on the surface of NdFeB to ensure the bonding strength between the coating and the substrate. However, the potential difference between the phases of NdFeB is large. If the pickling method is not good, it will cause uneven corrosion of the phases, and ultimately lead to poor coating quality of the electroplated product when electroplating is performed after pickling.

[0003] For the pre-treatment of rack-plated products, manual pickling is often used. A small amount of products are placed in a basket or a net bag, and they are manually pulled in the pickling tank for manual pickling. The products collide with each other, resulting in a certain proportion of missing corners. During the pickling process, the dimensions need to be measured many times to ensure that the tolerances are qualified before loading them into the designated rack and flowing into the electroplating line. Due to the small amount of manual pickling at one time, the pickling efficiency is low, it is difficult to ensure the stability between batches, the pickling consistency is poor, and it is difficult to meet the stability requirements of industrial mass production. For automatic pickling, the existing process often uses stirring methods such as compressed air stirring and continuous circulation filtration of pickling liquid in the pickling tank. However, since the parts are clamped on the designated rack, these two methods cannot thoroughly pickle the contact points between the rack and the parts, which is not conducive to the bonding of the coating during subsequent electroplating at the contact position. As a result, there are block-like protrusions at this location after electroplating, the bonding force is poor, and the coating is easy to peel off along this location.

[0004] Therefore, it is urgent to propose a magnet pickling treatment method with better pickling effect. Summary of the invention

[0005] The first object of the present invention is to provide a magnet pickling treatment method, through which the pickling amount consistency between batches of magnet substrates can be ensured, and the pickling effect of a single magnet substrate can be good.

[0006] The second object of the present invention is to provide a magnet pickling treatment device, which can improve the automatic pickling consistency of batch magnet substrates by pickling magnets, and is particularly suitable for magnet substrates with a unit weight of 36g-320g.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] The present invention discloses a magnet pickling treatment method, comprising: installing a magnet substrate on a hanger, and installing the hanger above a pickling tank, and immersing the magnet substrate in the pickling tank; driving the hanger and / or the pickling tank to move, so that the magnet substrate can reciprocate relative to the pickling liquid in the pickling tank along a first direction and a second direction at an angle, and the first direction is parallel to the liquid surface of the pickling liquid; wherein: in the cycle of reciprocating motion along the second direction, the movement time toward the liquid surface close to the pickling liquid is shorter than the movement time toward the liquid surface away from the pickling liquid, so that the magnet substrate can hit the pickling liquid; the movement amplitude of the magnet substrate relative to the pickling liquid along the second direction is L, the size of the magnet substrate along the second direction is H, and L and H satisfy the relationship: L / H=0.03-0.4.

[0009] In some embodiments, the movement frequency of the magnet substrate relative to the pickling liquid along the second direction is 50 times / minute to 150 times / minute.

[0010] In some embodiments, the initial acceleration of the magnet substrate relative to the pickling solution along the second direction is 480 cm / s 2 -500cm / s 2 .

[0011] In some embodiments, the movement frequency of the magnet substrate relative to the pickling liquid along the first direction is 10 times / minute to 30 times / minute.

[0012] In some embodiments, the initial acceleration of the magnet substrate relative to the pickling solution along the first direction is 2.35 cm / s 2 -28cm / s 2 .

[0013] In some embodiments, the pickling time of the magnet substrate is 180 seconds to 600 seconds; and / or: the pickling temperature of the magnet substrate is 20° C. to 40° C.

[0014] In some embodiments, the concentration of nitric acid in the pickling solution of the magnet substrate is 2%-3%; and / or: the weight of the magnet substrate is 36g-320g.

[0015] The present invention also discloses a magnet pickling treatment device, which is used to perform the magnet pickling treatment method described above; the magnet pickling treatment device comprises: a pickling tank, which is used to contain pickling liquid; a hanger, which has a plurality of hanging parts, each of which is used to hang at least one magnet substrate; a driving mechanism, which drives the pickling tank and / or the hanger to move; wherein: the driving mechanism drives the hanger and / or the pickling tank to move, so that the magnet substrate can move relative to the pickling tank. The pickling liquid reciprocates along a first direction and a second direction which are angled with each other, and the first direction is parallel to the liquid surface of the pickling liquid; wherein: in the period of reciprocating motion along the second direction, the movement duration toward the liquid surface close to the pickling liquid is shorter than the movement duration toward the liquid surface away from the pickling liquid, so that the magnet substrate can hit the pickling liquid; the movement amplitude of the magnet substrate relative to the pickling liquid along the second direction is L, the size of the magnet substrate along the second direction is H, and L and H satisfy the relationship: L / H=0.03-0.4.

[0016] In some embodiments, the driving mechanism includes a striking module and a swing module, the striking module is used to be connected to the hanger and used to drive the hanger to move along the second direction, and the swing module is connected to the pickling tank and used to drive the pickling tank to move along the first direction.

[0017] In some embodiments, the magnet pickling treatment device also includes a support frame, a support seat and a flybar, wherein the support frame is used to support the pickling tank, and the flybar is used to support the hanger; the support seat is used to support the flybar, and the driving mechanism includes a first driving module and a second driving module; wherein; the first driving module is connected to the support frame, and is used to drive the support frame to reciprocate along the first direction; the second driving module is installed on the support frame, and is used to drive the support seat to reciprocate along the first direction.

[0018] Beneficial effects of the present invention: The method disclosed in the present invention enables batches of magnet substrates to be placed on a hanger without being affected by the position of the hanger's hanging point during the pickling process, so that the pickling amount at each position of the magnet substrate is consistent, and the pickling amount of batches of magnet substrates is consistent.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 1 is a simplified flow chart of a magnet pickling treatment method according to an embodiment of the present invention;

[0021] Figure 2It is a simplified structural diagram of a magnet pickling treatment device according to an embodiment of the present invention.

[0022] Figure 3 It is a simplified structural diagram of a magnet pickling treatment device according to another embodiment of the present invention.

[0023] Reference numerals:

[0024] 100, pickling tank; 200, hanger; 300, driving mechanism; 310, striking module; 320, swing module; 330, first driving module; 340, second driving module;

[0025] 400, support frame; 500, support seat; 600, flying bar. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0027] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0029] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0030] The present invention discloses a magnet pickling treatment method, referring to Figure 1 As shown, the process of the magnet pickling treatment method is as follows:

[0031] S1: Install the magnet substrate on the hanger 200, and install the hanger 200 above the pickling tank 100, and immerse the magnet substrate in the pickling tank 100; it should be noted that the hanger 200 can be a hook-shaped structure, or a U-shaped or V-shaped structure with bottom and side supports. The specific structure of the hanger 200 can be selected according to the specific shape of the magnet substrate and the pickling requirements, and the specific structure of the hanger 200 is not limited here.

[0032] S2: driving the hanger 200 and / or the pickling tank 100 to move, so that the magnet substrate can reciprocate relative to the pickling liquid in the pickling tank 100 along the first direction and the second direction at an angle, the first direction being parallel to the liquid surface of the pickling liquid; in the reciprocating motion cycle along the second direction, the movement duration toward the liquid surface close to the pickling liquid is shorter than the movement duration toward the liquid surface away from the pickling liquid, so that the magnet substrate can "hit" the pickling liquid. It should be noted that in step S2, the hanger 200 can be driven to reciprocate along the first direction and the second direction by a driving mechanism 300, or the pickling tank 100 can be driven to move along the first direction and the second direction by a driving mechanism 300, or one of the pickling tank 100 and the hanger 200 can be driven to reciprocate along the first direction and the other along the second direction by two driving mechanisms 300. The specific movement form of the hanger 200 and the pickling tank 100 can be adjusted according to actual needs.

[0033] The inventor of the present disclosure has found through research that when the magnetic substrate is placed on the hanger 200, the problem of insufficient pickling of the magnetic substrate and insufficient pickling amount is likely to occur at the hanging point where the magnetic substrate contacts the hanger 200. In the prior art, the pickling degree at the hanging point of the magnetic substrate is increased by switching the hanging point, which requires multiple sets of hangers 200 or corresponding motion mechanisms to achieve the switching of the hanging point between two positions. On the one hand, such relatively fixed multiple hanging points still have the problem of insufficient pickling and insufficient pickling amount. On the other hand, the increase in the mechanism in the system reduces the stability of the mechanical system. With the long-term operation of the mechanical system, the stability of the pickling of the magnetic substrate is difficult to ensure. The present disclosure proposes a technical idea of ​​moving the magnetic substrate along its own central circumferential direction during the pickling process without adding any extra hangers 200 or motion mechanisms, so that the hanging point position where the magnetic substrate contacts the hanger 200 can be "continuously changed" during the pickling process, so that any circumferential position of the magnetic substrate during the pickling process is a hanging point. From another perspective, the hanging point of the magnetic substrate during the pickling process "disappears", thereby solving the problem of insufficient pickling of the hanging points while ensuring the stability of the entire pickling system.

[0034] In addition, under the above technical ideas, the inventors of the present disclosure have found that when the NdFeB magnet is pickled with nitric acid, reaction products such as nitrates and nitrogen oxides and neodymium-rich phase particles that are dissolved and detached from the magnet will be formed. These substances will continue to adsorb on the surface of the substrate to form a "dust layer". The untimely removal of the dust layer will affect the continuous pickling process of the magnet substrate, and will also make the subsequent ultrasonic cleaning dust removal amount larger and the removal time increase. At the same time, tiny corrosion holes will form on the surface of the NdFeB substrate after nitric acid pickling. Compared with smooth areas, these holes are more likely to store the generated gas, and the gas is more likely to gather and stay here. Since it cannot escape and detach in time, it hinders the further release of hydrogen ions inside the magnet substrate. It is understandable that, in the actual pickling process, the magnet substrate can reciprocate relative to the pickling liquid in the pickling tank 100 along the first direction and the second direction at an angle, the first direction is parallel to the liquid surface of the pickling liquid, and the magnet substrate can reciprocate relative to the pickling liquid along the direction of its liquid surface plane, and can take away the gas during the pickling process, so that the gas at the hanging point (the contact point between the magnet substrate and the hanger 200) is separated from the magnet substrate. Since the magnet substrate can hit the pickling liquid during the reciprocating movement along the second direction, not only can the magnet substrate with a larger unit weight be separated from the hanger 200 instantly, but also the reaction products such as nitrate adsorbed on the surface of the magnet substrate outside the hanging point can be partially peeled off from the magnet substrate at the same time, improving the dust hanging phenomenon. In addition, since the magnet substrate can reciprocate relative to the pickling liquid in the pickling tank 100 along the first direction and the second direction at an angle, it can ensure that the pickling amount between batches of magnet substrates is highly consistent, the pickling amount of a single magnet substrate is consistent at each location in the circumferential direction, and the pickling effect of a single magnet substrate is good.

[0035] Optionally, the first direction is the horizontal direction and the second direction is the vertical direction. Thus, in the actual pickling process, by controlling the parameters of the first direction and the second direction, the magnet substrate can be rotated circumferentially in the pickling solution, thereby further ensuring the consistency of the pickling amount between batches of magnet substrates, the consistency of the pickling amount at various locations in the circumferential direction of a single magnet substrate, and the pickling effect of a single magnet substrate. Of course, in other embodiments of the present invention, the first direction and the second direction can be selected according to actual needs, and the first direction and the second direction may not be set vertically.

[0036] Optionally, the movement amplitude of the magnetic substrate relative to the pickling liquid along the second direction is L, and the size of the magnetic substrate along the second direction is H, and L and H satisfy the relationship: L / H=0.03-0.4. It can be understood that, according to the foregoing, during the movement of the magnetic substrate relative to the pickling liquid along the second direction, the magnetic substrate can hit the pickling liquid, which can not only achieve the instant separation of the magnetic substrate with a larger single weight from the hanger 200, but also if the movement amplitude of the magnetic substrate relative to the pickling liquid along the second direction is too large, the magnetic base will fall during the throwing process. If the amplitude is too small, the above-mentioned separation and rotation effect cannot be achieved. In this embodiment, the amplitude of the magnetic substrate relative to the pickling liquid along the second direction is controlled by controlling the ratio of the size of the magnetic substrate along the second direction and the movement amplitude of the magnetic substrate relative to the pickling liquid along the second direction, thereby ensuring the pickling consistency and pickling effect of the magnetic substrate. Of course, in other embodiments of the present invention, the ratio of the movement amplitude of the magnet substrate relative to the pickling liquid along the second direction and the size of the magnet substrate along the second direction can also be selected according to actual needs, and the amplitude of the magnet substrate along the second direction can also be controlled by controlling the movement parameters of the magnet substrate along the second direction. Optionally, L / H can be 0.03, 0.05, 0.1, 0.15, 0.18, 0.2, 0.23, 0.25, 0.27, 0.3, 0.32, 0.35, 0.37, 0.4, preferably, L / H is 0.03-0.25. Under the above preference, a more sufficient and thorough separation and rotation effect can be achieved.

[0037] Optionally, the motion frequency of the magnet substrate relative to the pickling solution along the second direction is 50 times / minute-150 times / minute. Wherein, the definition of "times" in the motion frequency refers to completing a reciprocating motion. Specifically, the motion frequency of the magnet substrate relative to the pickling solution along the second direction can be 50 times / minute, 55 times / minute, 60 times / minute, 65 times / minute, 70 times / minute, 75 times / minute, 80 times / minute, 85 times / minute, 90 times / minute, 95 times / minute, 100 times / minute, 105 times / minute, 110 times / minute, 115 times / minute, 120 times / minute, 125 times / minute, 130 times / minute, 135 times / minute, 140 times / minute, 145 times / minute, 150 times / minute. Of course, the motion frequency can also be other values ​​within the range of 50 times / minute-150 times / minute, and is not limited to the above examples. It can be understood that if the movement frequency of the magnetic substrate relative to the pickling liquid along the second direction is too fast or too slow, it is not conducive to the instantaneous separation of the magnetic substrate with a larger unit weight from the hanger 200. Controlling the movement frequency of the magnetic substrate relative to the pickling liquid along the second direction at 50 times / minute-150 times / minute is conducive to ensuring the instantaneous separation of the magnetic substrate with a larger unit weight from the hanger 200, thereby helping to improve the dust hanging phenomenon.

[0038] Optionally, the initial acceleration of the magnet substrate relative to the pickling liquid along the second direction is 480 cm / s 2 -500cm / s 2 Specifically, the initial acceleration of the magnet substrate relative to the pickling liquid along the second direction can be 480 cm / s 2 , 481cm / s 2 , 482cm / s 2 , 483cm / s 2 , 484cm / s 2 , 485cm / s 2 , 486cm / s 2 , 487cm / s 2 、488cm / s 2 、489cm / s 2 、490cm / s 2 、491cm / s 2 , 492cm / s 2 、493cm / s 2 、494cm / s 2 , 495cm / s 2 , 496cm / s 2 、497cm / s 2 , 498cm / s 2 、499cm / s 2 , 500cm / s 2Of course, the initial acceleration can also be 480cm / s 2 -500cm / s 2 It is understood that the initial acceleration of the magnet substrate relative to the pickling liquid along the second direction is too fast or too slow. The magnet substrate with a large weight is separated from the hanger 200 instantly. The initial acceleration of the magnet substrate relative to the pickling liquid along the second direction is 480 cm / s 2 -500cm / s 2 This is helpful to ensure that the magnet substrate with a larger single weight is separated from the hanger 200 instantly, thereby helping to improve the dust hanging phenomenon.

[0039] Optionally, the movement frequency of the magnet substrate relative to the pickling solution along the first direction is 10 times / minute to 30 times / minute. Specifically, the movement frequency of the magnet substrate relative to the pickling solution along the first direction can be 10 times / minute, 11 times / minute, 12 times / minute, 13 times / minute, 14 times / minute, 15 times / minute, 16 times / minute, 17 times / minute, 18 times / minute, 19 times / minute, 20 times / minute, 21 times / minute, 22 times / minute, 23 times / minute, 24 times / minute, 25 times / minute, 26 times / minute, 27 times / minute, 28 times / minute, 29 times / minute, 30 times / minute. Of course, the movement frequency can also be other values ​​within the range of 10 times / minute to 30 times / minute, and is not limited to the above examples. It can be understood that if the movement frequency of the magnetic substrate relative to the pickling liquid along the first direction is too fast or too slow, it is not conducive to improving the pickling effect and the pickling consistency. Controlling the movement frequency of the magnetic substrate relative to the pickling liquid along the first direction to 10 times / minute-30 times / minute is conducive to ensuring the pickling effect and improving the pickling consistency.

[0040] Optionally, the initial acceleration of the magnet substrate relative to the pickling liquid along the first direction is 2.35 cm / s 2 -28cm / s 2 Specifically, the initial acceleration of the magnet substrate relative to the pickling liquid along the first direction can be 2.35 cm / s 2 , 3cm / s 2 , 4cm / s 2 , 5cm / s 2 , 6cm / s 2 , 7cm / s 2 , 8cm / s 2 , 9cm / s 2 , 10cm / s 2 , 11cm / s 2 , 12cm / s 2 , 13cm / s 2 , 14cm / s 2 , 15cm / s2 , 16cm / s 2 , 17cm / s 2 , 18cm / s 2 , 19cm / s 2 , 20cm / s 2 , 21cm / s 2 , 22cm / s 2 , 23cm / s 2 , 24cm / s 2 , 25cm / s 2 , 26cm / s 2 , 27cm / s 2 , 28cm / s 2 Of course, the initial acceleration can also be 2.35cm / s 2 -28cm / s 2 Other values ​​within the range are not limited to the above examples. It is understandable that the initial acceleration of the magnet substrate relative to the pickling liquid along the first direction is too fast or too slow, which is not conducive to improving the pickling effect and pickling consistency. The initial acceleration of the magnet substrate relative to the pickling liquid along the first direction is 2.35 cm / s 2 -28cm / s 2 , which is beneficial to ensure the pickling effect and improve the pickling consistency.

[0041] Optionally, the pickling time of the magnet substrate is 180 seconds to 600 seconds. If the pickling time of the magnet substrate is too long or too short, it is not conducive to ensuring the pickling effect. The pickling time of the magnet substrate is controlled within the range of 300 seconds to 600 seconds, which can improve the pickling effect. Of course, in other embodiments of the present invention, the pickling time of the magnet substrate can be selected according to actual needs and is not limited to the above limitation.

[0042] Optionally, the pickling temperature of the magnet substrate is 20°C-40°C. Too high or too low a pickling temperature of the magnet substrate is not conducive to ensuring the pickling effect. Controlling the pickling temperature of the magnet substrate within the range of 20°C-40°C can improve the pickling effect. Of course, in other embodiments of the present invention, the pickling temperature of the magnet substrate can be selected according to actual needs and is not limited to the above limitation.

[0043] Optionally, the nitric acid concentration in the pickling solution of the magnet substrate is 2%-3%; too high or too low a nitric acid concentration in the pickling solution is not conducive to ensuring the pickling effect, and controlling the nitric acid concentration within the range of 2%-3% can improve the pickling effect. Of course, in other embodiments of the present invention, the nitric acid concentration in the pickling solution can be selected according to actual needs and is not limited to the above limitations.

[0044] Optionally, the weight of the magnet substrate is 36 g to 320 g. Of course, in other embodiments of the present invention, the magnet substrate can be selected according to specific product requirements and is not limited to the above range.

[0045] Preferably, the shape of the magnet substrate may be annular, cylindrical, elliptical, or partially arc-shaped.

[0046] Optionally, the magnet substrate composition is the composition of RTBM, specifically: R represents a rare earth element, and its mass proportion is 28wt%-31.5wt%; R is selected from at least one of Nd and (Pr, La, Ce, Dy, Tb, Ho); B has a mass proportion of 0.85wt%-1.05wt% or less; M has a mass proportion of less than 3wt%, and is selected from one or more of Cu, Zn, Ga, Zr, Ti, Nb, Al, Ag, and W, and T is selected from Fe and / or Co and other impurity elements, wherein Fe accounts for more than 97wt% of the total amount of T, and the mass proportion of T is the remainder excluding R, B, and M.

[0047] The present invention also discloses a magnet pickling treatment device, referring to Figure 2 and Figure 3 As shown, the magnet pickling treatment device is used to perform the magnet pickling treatment method described above. The magnet pickling treatment device includes a pickling tank 100 and a hanger 200. The pickling tank 100 is used to contain pickling liquid. The hanger 200 has multiple hanging parts, each of which is used to hang at least one magnet substrate. The driving mechanism 300 drives the pickling tank 100 and / or the hanger 200 to move. The driving mechanism 300 drives the hanger 200 and / or the pickling tank 100 to move, so that the magnet substrate can reciprocate relative to the pickling liquid in the pickling tank 100 along the first direction and the second direction at an angle, and the first direction is parallel to the liquid surface of the pickling liquid; in the reciprocating motion cycle along the second direction, the movement time toward the liquid surface close to the pickling liquid is less than the movement time toward the liquid surface away from the pickling liquid, so that the magnet substrate can "hit" the pickling liquid.

[0048] In the actual pickling process, the driving mechanism 300 can drive the pickling tank 100 and / or the hanger 200 to move, so that the magnetic substrate hung on the hanger 200 can reciprocate relative to the pickling liquid in the pickling tank 100 along the first direction and the second direction at an angle. The magnetic substrate can reciprocate relative to the pickling liquid along the first direction, and can take away the gas during the pickling process, so that the gas at the contact point between the magnetic substrate and the hanger 200 is separated from the magnetic substrate. The magnetic substrate moves back and forth relative to the pickling liquid along the second direction, so that the magnetic substrate hits the pickling liquid, which can not only achieve instant separation of the magnetic substrate with a large unit weight from the hanger 200, but also can separate the reaction products such as nitrate adsorbed on the surface of the magnetic substrate outside the hanging point from the magnetic substrate part, thereby improving the dust hanging phenomenon. In addition, since the magnet substrate can move in two directions relative to the pickling liquid in the pickling tank 100, the pickling amount consistency between batches of magnet substrates can be ensured, the pickling amount of a single magnet substrate at each location in the circumferential direction is consistent, and the pickling effect of a single magnet substrate is good.

[0049] In a specific embodiment, reference Figure 2 As shown, the driving mechanism 300 includes a striking module 310 and a swinging module 320. The striking module 310 is used to be connected to the hanger 200 and used to drive the hanger 200 to move in the second direction, and the swinging module 320 is connected to the pickling tank 100 and used to drive the pickling tank 100 to move in the first direction. It should be noted that splitting the driving mechanism 300 into the striking module 310 and the swinging module 320 is conducive to controlling the motion parameters of the hanger 200 and the pickling tank 100, and simplifies the structure of the entire magnet pickling treatment device, reducing the manufacturing cost of the magnet pickling treatment device. In an embodiment of the present invention, the striking module 310 can be a structure of an eccentric wheel driven by a motor, a cylinder push rod, or a motor-driven four-bar mechanism or other motion mechanism. The specific type of the striking module 310 can be selected according to actual needs, as long as it can ensure that the hanger 200 can move in the second direction, and in the cycle of reciprocating motion in the second direction, the movement time of the magnet substrate toward the liquid surface close to the pickling liquid is less than the movement time toward the liquid surface away from the pickling liquid, so that the magnet substrate can strike the pickling liquid. The swing module 320 can be a structure of an eccentric wheel driven by a motor, a cylinder push rod, a ball screw structure driven by a motor, or a gear rack movement driven by a motor, as long as it can ensure that the pickling tank 100 can stably reciprocate in the first direction. Of course, in an alternative embodiment, the striking module 310 can also be connected to the pickling tank 100 and used to drive the pickling tank 100 to move in the second direction, and the swing module 320 is connected to the hanger 200 and used to drive the hanger 200 to move in the first direction, as long as the movement form described above can be guaranteed.

[0050] In another specific embodiment, referring to Figure 3 As shown, the magnet pickling treatment device also includes a support frame 400, a support seat 500 and a flybar 600. The support frame 400 is used to support the pickling tank 100, the flybar 600 is used to support the hanger 200, and the support seat 500 is used to support the flybar 600; the driving mechanism 300 includes a first driving module 330 and a second driving module 340. The first driving module 330 is connected to the support frame 400 and is used to drive the support frame 400 to reciprocate along the first direction; the second driving module 340 is installed on the support frame 400 and is used to drive the support seat 500 to reciprocate along the second direction. It can be understood that after the hanger 200 is installed on the feba 600, multiple magnetic substrates are hung on the hanger 200. During the pickling process, the second driving module 340 can drive the support seat 500 to move along the second direction. Since the feba 600 is installed on the support seat 500, during the movement of the support seat 500 along the second direction, the feba 600 can drive the hanger 200 to reciprocate along the second direction. The first driving module 330 can drive the support frame 400 to move along the first direction. The support frame 400 serves as a supporting member of the support seat 500, the feba 600 and the second driving module 340. When the support frame 400 moves along the first direction, the hanger 200 can move along the first direction, thereby realizing the movement of the hanger 200 relative to the pickling tank 100 along the first direction and the second direction.

[0051] It should be noted that, in the embodiments of the present invention, the first drive module 330 and the second drive module 340 can be a structure of a motor-driven eccentric wheel, a cylinder push rod, a motor-driven ball screw structure, or a motor-driven rack and pinion movement. As long as it is a linear reciprocating drive structure that can drive the support seat 500 and the support frame 400 to move, the specific types of the first drive module 330 and the second drive module 340 are not limited herein.

[0052] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0053] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

[0054] The present disclosure is further illustrated below by way of examples, but the present disclosure is not limited thereby. The NdFeB magnet substrate in the following embodiments and comparative examples can be represented by (PrNd)29.5Co0.7B0.91Cu0.1Ga0.1Zr0.2Fe68.49, and the preparation method is as follows: the raw materials are smelted according to the formula, and an alloy quick-solidification sheet with a thickness of 0.3 mm is obtained by a conventional rapid solidification method; then hydrogen cracking is performed, and then gas grinding is performed to a powder with an average particle size of 4.2 μm, and the composition of the gas includes air, carbon-containing solvents, lubricants and antioxidants conventional in the art; then the powder is oriented and formed in a 2T magnetic field, and sintered after static pressing, the sintering temperature is 1000°C, and the sintering time is 8h; after cooling to 900°C, primary aging is performed for 3h, and then the temperature is cooled to 500°C for secondary aging for 5h to obtain a magnetic blank; after cutting the magnetic blank, a magnet substrate with a size of Φ50mm*5mm is obtained, and the unit weight of the magnet substrate is 73.3g.

[0055] Example 1

[0056] Embodiment 1 provides a method for preparing a neodymium iron boron magnet, the method comprising the following steps:

[0057] The magnet substrate is mounted on the hanger 200, the size of the magnet substrate in the second direction is H=50mm, and the hanger 200 is mounted above the pickling tank 100, and the magnet substrate is immersed in the pickling tank; the hanger 200 and the pickling tank 100 are driven to move, so that the magnet substrate can reciprocate relative to the pickling liquid in the pickling tank 100 along the first direction and the second direction at an angle, the first direction is parallel to the liquid surface of the pickling liquid; the second direction is at an angle of 90° to the liquid surface of the pickling liquid. During the reciprocating motion cycle along the second direction, the motion frequency in the second direction is 80 times / minute, and the initial acceleration in the second direction is 480cm / s 2 In the cycle of reciprocating motion along the first direction, the motion frequency in the first direction is 30 times / minute, and the initial acceleration in the first direction is 20 cm / s 2, the ratio of the movement amplitude of the magnet substrate along the second direction equivalent to the pickling liquid to the size along the second direction is 0.18, that is, the movement amplitude along the second direction L = 9mm, the pickling temperature of the pickling liquid is 25°C, and the pickling time is 300 seconds. The hanger 200 carrying the magnet substrate is installed above the clean water tank and ultrasonically washed to obtain a neodymium iron boron magnet.

[0058] Example 2

[0059] The NdFeB magnet was prepared by the same method as in Example 1, except that the angle between the second direction and the liquid surface of the pickling solution was 60°, the movement frequency of the second direction was 100 times / min during the reciprocating motion cycle along the second direction, and the initial acceleration of the second direction was 483 cm / s 2 .

[0060] Example 3

[0061] The NdFeB magnet was prepared by the same method as in Example 1, except that, during the period of reciprocating motion along the first direction, the motion frequency in the first direction was 10 times / min, and the initial acceleration in the first direction was 2.45 cm / s 2 .

[0062] Comparative Example 1

[0063] The NdFeB magnet is prepared by the same method as in Example 1, except that there is no reciprocating motion in the second direction, that is, the motion frequency in the second direction is 0.

[0064] Comparative Example 2

[0065] The NdFeB magnet was prepared by the same method as in Example 1, except that the ratio of the movement amplitude of the magnet substrate along the second direction corresponding to the pickling liquid to the size along the second direction was 2.

[0066] Comparative Example 3

[0067] The NdFeB magnet was prepared by the same method as in Example 1, except that the initial acceleration in the second direction was 50 cm / s 2 , the initial acceleration in the first direction is 50cm / s 2 .

[0068] Test Case

[0069] The NdFeB magnets prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were tested for the circumferential dimensions, dust removal amount, and average pickling amount of the magnets using the following method. The test results are shown in Table 1.

[0070] (1) Circumferential dimensions of the magnet: Use a micrometer to measure the thickness of the NdFeB magnet at any two locations on its circumference and record the data;

[0071] (2) Dust removal: After the magnet substrate is pickled with nitric acid in the pickling tank, it is placed in an ultrasonic cleaning tank and ultrasonically washed for 10 seconds. The magnet substrate is then taken out for an appearance test of the degree of dust on the surface and the brightness of the dust layer is observed.

[0072] (3) Average pickling amount: The pickling amount of two batches of NdFeB magnets was tested using a micrometer. Twenty NdFeB magnets were sampled from each batch, and the average pickling amount of the NdFeB magnets between the two batches was calculated.

[0073] Table 1

[0074]

[0075] It can be seen from the circumferential dimension data of Examples 1-3 and Comparative Examples 1-3 that the magnets prepared by the method of the present invention have a small difference in thickness at any two positions on the circumference of the magnet, the pickling amount at each position of the magnet is consistent, and the automatic pickling effect is good. It can be seen from the dust removal data that the magnets prepared by the method of the present invention have a good dust removal effect, which can significantly improve the dust phenomenon during the pickling process. After a short period of ultrasound, a large amount of dust can be removed from the magnets, presenting a bright white appearance. It can be seen from the average pickling amount data that the magnets prepared by the method of the present invention have similar pickling amounts between different batches, indicating that the pickling amount control consistency of batch products is good. It should be noted that in Comparative Example 2, since L / H is not within the scope of the present invention, a large amount of magnet substrates fell from the hanger during the pickling process, resulting in a low yield of the final batch pickling, so there is no corresponding data.

[0076] The present invention illustrates the detailed features of the present invention through the above embodiments, but the present invention is not limited to the above detailed features, that is, it does not mean that the present invention must rely on the above detailed features to be implemented. Those skilled in the art should understand that any improvement to the present invention, equivalent replacement of the technical features selected by the present invention, addition of auxiliary technical features, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A magnet pickling method, characterized in that: include: Mounting a magnetic substrate on a hanger (200), and mounting the hanger (200) above a pickling tank (100), and immersing the magnetic substrate in the pickling tank (100); The hanger (200) and / or the pickling tank (100) are driven to move, so that the magnetic substrate can reciprocate relative to the pickling liquid in the pickling tank (100) along a first direction and a second direction forming an angle, wherein the first direction is parallel to the liquid surface of the pickling liquid; wherein: In the cycle of the reciprocating motion along the second direction, the duration of the motion toward the liquid surface close to the pickling liquid is shorter than the duration of the motion toward the liquid surface away from the pickling liquid, so that the magnet substrate can hit the pickling liquid; The movement amplitude of the magnet substrate relative to the pickling liquid along the second direction is L, the size of the magnet substrate along the second direction is H, and L and H satisfy the relationship: L / H=0.03-0.

4.

2. The magnet pickling method according to claim 1, characterized in that: The movement frequency of the magnet substrate relative to the pickling liquid along the second direction is 50 times / minute to 150 times / minute.

3. The magnet pickling method according to claim 1, characterized in that: The initial acceleration of the magnet substrate relative to the pickling liquid along the second direction is 480 cm / s 2 -500cm / s 2 .

4. The magnet pickling method according to claim 1, characterized in that: The movement frequency of the magnet substrate relative to the pickling liquid along the first direction is 10 times / minute to 30 times / minute.

5. The magnet pickling method according to claim 1, characterized in that: The initial acceleration of the magnet substrate relative to the pickling solution along the first direction is 2.35 cm / s 2 -28cm / s 2 .

6. The magnet pickling method according to claim 1, characterized in that: The pickling time of the magnet substrate is 180 seconds to 600 seconds; and / or: The pickling temperature of the magnet substrate is 20°C-40°C.

7. The magnet pickling method according to claim 1, characterized in that: The concentration of nitric acid in the pickling solution of the magnet substrate is 2%-3%; and / or: The weight of the magnet substrate is 36 g to 320 g.

8. A magnet pickling treatment device, characterized in that: The magnet pickling treatment device is used to perform the magnet pickling treatment method according to any one of claims 1 to 7; The magnet pickling treatment device comprises: A pickling tank (100), wherein the pickling tank (100) is used to contain pickling liquid; A hanger (200), wherein the hanger (200) has a plurality of hanging parts, each of the hanging parts being used to hang at least one of the magnetic substrates; A driving mechanism (300), wherein the driving mechanism (300) drives the pickling tank (100) and / or the hanger (200) to move; wherein: The driving mechanism (300) drives the hanger (200) and / or the pickling tank (100) to move, so that the magnetic substrate can reciprocate relative to the pickling liquid in the pickling tank (100) along a first direction and a second direction that are angled, and the first direction is parallel to the liquid surface of the pickling liquid; wherein: In the cycle of the reciprocating motion along the second direction, the duration of the motion toward the liquid surface close to the pickling liquid is shorter than the duration of the motion toward the liquid surface away from the pickling liquid, so that the magnet substrate can hit the pickling liquid; The movement amplitude of the magnet substrate relative to the pickling liquid along the second direction is L, the size of the magnet substrate along the second direction is H, and L and H satisfy the relationship: L / H=0.03-0.

4.

9. The magnet pickling treatment device according to claim 8, characterized in that: The driving mechanism (300) comprises a striking module (310) and a swinging module (320); the striking module (310) is used to be connected to the hanger (200) and to drive the hanger (200) to move along the second direction; the swinging module (320) is connected to the pickling tank (100) and to drive the pickling tank (100) to move along the first direction.

10. The magnet pickling treatment device according to claim 8, characterized in that: The magnet pickling treatment device further comprises a support frame (400), a support seat (500) and a flybar (600), wherein the support frame (400) is used to support the pickling tank (100), the flybar (600) is used to support the hanger (200), and the support seat (500) is used to support the flybar (600); the driving mechanism (300) comprises a first driving module (330) and a second driving module (340); in ； The first driving module (330) is connected to the support frame (400) and is used to drive the support frame (400) to reciprocate along the first direction; The second driving module (340) is mounted on the support frame (400) and is used to drive the support seat (500) to reciprocate along the second direction.

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