WO2022006971A1

WO2022006971A1 - Powder passivation device and method

Info

Publication number: WO2022006971A1
Application number: PCT/CN2020/102614
Authority: WO
Inventors: 孙欢; 李犇; 王明波; 曾基灵
Original assignee: 瑞声声学科技(深圳)有限公司; 瑞声科技（南京）有限公司
Priority date: 2020-07-10
Filing date: 2020-07-17
Publication date: 2022-01-13
Also published as: CN111922332A

Abstract

Provided in the present application are a powder passivation device and method, the powder passivation device comprising: a box body, a box door and glove operating holes being provided on the box body, and rubber gloves being provided in the glove operating holes; an oxygen discharge device, which is provided on the box body and comprises a gas lead-in valve and an exhaust valve which are connected to an argon gas source; an oxygen meter, which is provided within the box body and used for measuring the oxygen content within the box body; and a control device, which comprises a controller connected to the oxygen meter and a solenoid valve that is disposed on the box body and that is connected to the controller. The controller controls the opening and closing of the solenoid valve according to feedback information of the oxygen meter, such that air enters or is prevented from entering, and then the oxygen content within the box body is controlled to be within a preset range. By using the described device, the speed of powder oxidation may be controlled according to the characteristics of the powder, so that the powder is slowly oxidized, avoiding excessive heating and spontaneous combustion, reducing the risk of powder combustion, and ensuring safety, and meanwhile, saving workers' time.

Description

Passivation powder device and method

technical field

The present application relates to the technical field of powder powder processing, in particular to a passivation powder device and method.

Background technique

Ultrafine/nano powders generally have the characteristics of high activity due to their large specific surface area. Once exposed to the air, some powders will be rapidly oxidized and burned, and some ultrafine/nano powders will still have crystal grains during storage. Growth phenomena, which all affect the properties of the powder and the specific use of sintering.

NdFeB permanent magnet material has the characteristics of high remanence, high coercive force and high magnetic energy product. It is the most widely used type of permanent magnet material at present. and other fields. With the continuous advancement of science and technology, the application range of sintered NdFeB permanent magnet materials is more and more extensive, and higher and higher requirements are also placed on the magnetic properties of sintered NdFeB permanent magnet materials.

Sintered NdFeB belongs to a class of powder metallurgy functional materials, and the structure of the material plays a decisive role in the performance of the material. Therefore, it is necessary to explore the structure of the material in the research and development process of NdFeB materials. NdFeB powder Both the particle size and morphology of the sintered NdFeB have a great influence on the final properties of the sintered NdFeB. In the research and development process of NdFeB, the particle size and morphology of the powder should be frequently measured, and the particle size and morphology of the powder should be frequently measured in the production process to adjust the powder making process. However, due to the size effect, 3-5um NdFeB powder is very easy to spontaneously ignite in the air, so it is necessary to passivate the sintered NdFeB powder before measuring the particle size and morphology of the powder. In addition, a large amount of passivated NdFeB powder is also required in the debugging process of some new NdFeB forming and sintering equipment. Usually hand-passivated NdFeB powder is prone to spontaneous combustion, which is dangerous; when a large amount of passivation powder is used, a large amount of powder needs to be manually passivated, which will also waste the time of relevant researchers; The device for passivating NdFeB powder can effectively solve the danger in the process of passivating powder and save the precious time of researchers.

Therefore, it is necessary to provide a passivation powder device and method to solve the above problems.

technical problem

The purpose of this application is to provide a passivation powder device and method, the above-mentioned passivation powder device controls the switch of the solenoid valve according to the oxygen content in the box measured by the oxygen meter, controls the entry of air, and then controls the speed of powder oxidation , to avoid excessive heat and spontaneous combustion of the powder.

technical solutions

The technical solution of the present application is as follows: a passivation powder device, the passivation powder device comprises:

a box body, a box door and a glove operation hole are arranged on the box body, and rubber gloves are arranged on the glove operation hole;

The oxygen exhaust device provided in the box body includes a gas inlet valve and an exhaust valve connected with the argon gas source;

an oxygen meter arranged in the box for measuring the oxygen content in the box;

And, a control device, comprising a controller connected with the oxygen meter and a solenoid valve arranged on the box body and connected with the controller, the controller controls the oxygen meter according to the feedback information of the oxygen meter The solenoid valve is opened or closed to allow or prevent air from entering, thereby controlling the oxygen content in the tank to be within a preset range.

Preferably, the passivation powder device further includes a stainless steel tray placed in the box and used to hold the powder.

Preferably, the box body includes a front wall and a rear wall arranged opposite to each other and two side walls arranged opposite to each other, the box door is arranged on the front wall, and the glove operation hole is arranged on one of the side walls superior.

This application also mentions a kind of passivation powder method, and described passivation powder method comprises the following steps:

Put the vacuum-packaged powder into the box through the box door;

Open the gas introduction valve to introduce argon into the box, open the exhaust valve and the switch of the oxygen meter, continue to introduce argon and exhaust the gas in the box, and detect the oxygen content in the box. When the oxygen content in the box is less than or equal to the first preset value, close the gas introduction valve and the exhaust valve;

Disassemble the vacuum package of the powder through the rubber gloves of the box, and expose the powder to the oxygen-containing environment in the box;

Turn on the controller, receive the feedback information of the oxygen meter, control the opening or closing of the solenoid valve according to the feedback information to allow air to enter or prevent the air from entering, and control the oxygen content in the box within a preset range, The powder is continuously passivated in an oxygen-containing environment with an oxygen content within the preset range.

Preferably, the opening or closing of the solenoid valve is controlled according to the feedback information to allow or prevent air from entering, and the oxygen content in the box is controlled within a preset range, including:

When the oxygen content in the feedback information is lower than the minimum value within the preset range, control the solenoid valve to open; when the oxygen content in the feedback information is higher than the maximum value within the preset range, control the The solenoid valve is closed.

Preferably, the passivation powder method further comprises:

According to the feedback information, when the change of the oxygen content in the box in half an hour is less than the second preset value, the powder is completely passivated. After closing the oxygen meter and the controller The passivation powder can be taken out by opening the box door.

Preferably, the powder is NdFeB powder, the first preset value is 200ppm, and the preset range is 1000ppm~ 1500ppm, the second preset value is 100ppm.

Preferably, the exposing the powder in the box includes: uniformly laying the powder on a stainless steel tray in the box.

beneficial effect

The beneficial effects of the present application are as follows: the present application provides a passivation powder device and method, the passivation powder device comprises: a box body, the box body is provided with a box door and a glove operation hole, the glove The operation hole is provided with rubber gloves; the oxygen exhaust device provided in the box body includes a gas inlet valve and an exhaust valve connected to the argon gas source; it is provided in the box body for measuring the oxygen content in the box body The oxygen measuring instrument; and, a control device, including a controller connected with the oxygen measuring instrument and a solenoid valve provided on the box body and connected with the controller, the controller according to the oxygen measuring instrument The feedback information controls the solenoid valve to open or close to allow or prevent air from entering, thereby controlling the oxygen content in the tank to be within a preset range. Through the above device, the speed of powder oxidation can be controlled according to the characteristics of the powder itself, so that the powder can be slowly oxidized at a specific speed, avoiding excessive heat and spontaneous combustion, reducing the risk of powder burning, ensuring safety, and saving staff time. .

Description of drawings

FIG. 1 is a schematic structural diagram of a passivation powder device according to an embodiment of the present application.

FIG. 2 is a flowchart of a method for passivating powder according to an embodiment of the present application.

Description of drawings: passivation powder device 100; tray 1; rubber gloves 2; box door 3; oxygen measuring instrument 4; programmable logic controller (PLC controller) 5; exhaust valve 6; solenoid valve 7; gas introduction valve 8; box 9; front wall 91; side wall 92.

Embodiments of the present invention

The present application will be further described below with reference to the accompanying drawings and embodiments.

Please refer to FIG. 1 , which is a passivation powder device 100 according to an embodiment of the present application. The passivation powder device 100 includes a box body 9 . The box body 9 is provided with a box door 3 and a glove operation hole (not shown in the figure). The glove operation The hole is provided with rubber gloves 2; the oxygen exhaust device located in the box 9 includes a gas inlet valve 8 and an exhaust valve 6 connected to the argon gas source; it is located in the box 9 for measuring the oxygen in the box 9 The oxygen measuring instrument 4 of the content; And, the control device comprises the PLC controller 5 that is connected with the oxygen measuring instrument 4 and the solenoid valve 7 that is arranged in the casing 9 and is connected with the PLC controller 5, and the PLC controller 5 is based on the oxygen measuring instrument 5. The feedback information of the meter 4 controls the solenoid valve 7 to open or close to allow or prevent air from entering, thereby controlling the oxygen content in the box 9 to be within a preset range. Optionally, the box body 9 includes a front wall 91 and a rear wall (not shown) arranged oppositely and two side walls 92 arranged oppositely. The box door 3 is arranged on the front wall 91, and the glove operation hole is arranged on one side. on wall 92. Optionally, the passivation powder device 100 further includes a stainless steel tray 1 arranged in the box body 9 for containing powder.

Specifically, the box door 3 is used for taking powder and releasing powder; the rubber gloves 2 are used for the staff to operate the powder in the box 9 outside the box 9; the oxygen exhaust device is used for discharging argon gas. The air in the box 9 controls the oxygen content in the box 9 to be below the first preset value, and then safely exposes the powder to the box 9, wherein the first preset value is determined according to the characteristics of the powder, The powder will not spontaneously ignite after rapid oxidation in the oxygen content below the first preset value; the control device controls the switch of the solenoid valve 7 through the PLC controller 5 according to the feedback information of the oxygen measuring instrument 4, and then controls the entry of air to The oxygen content in the box 9 is controlled within a preset range, so that the powder is slowly oxidized, wherein the preset range is determined according to the characteristics of the powder, and the powder can be slowly passivated within the oxygen content within the preset range.

The passivation powder device of the present application can control the opening and closing of the solenoid valve 7 according to the oxygen content in the box 9, control the entry of air or prevent the entry of air, and then control the speed of powder oxidation, so that the powder can be oxidized at a specific speed. Slow oxidation to avoid excessive heat and spontaneous combustion of powder. The risk of powder burning can be reduced, and the automatic passivation of powder can save staff time.

Based on the above-mentioned passivation powder device 100, please refer to FIG. 2, the present application also provides a passivation powder method, including the following steps:

In step S1 , the vacuum-packaged powder is placed in the box body 9 through the box door 3 .

Step S2, open the gas introduction valve 8 to introduce argon into the box 9, open the exhaust valve 6 and the switch of the oxygen meter 4 at the same time, continue to introduce argon and discharge the gas in the box 9, and detect the gas in the box 9. Oxygen content, when the oxygen content in the tank 9 is less than or equal to the first preset value, the gas inlet valve 8 and the exhaust valve 6 are closed.

In step S3 , the vacuum package of the powder is disassembled through the rubber gloves 2 of the box 9 , and the powder is exposed to the oxygen-containing environment in the box 9 .

Step S4, open the PLC controller 5, receive the feedback information of the oxygen measuring instrument 4, control the opening or closing of the solenoid valve 7 according to the feedback information to allow air to enter or prevent the air from entering, and control the oxygen content in the box 9 to a preset value. range, the powder is continuously passivated in an oxygen-containing environment with an oxygen content within a preset range.

Step S5, according to the feedback information, when the change of the oxygen content in the box 9 in half an hour is less than the second preset value, the powder is completely passivated, and the box is opened after closing the oxygen measuring instrument 4 and the PLC controller 5. The door 3 can take out the passivation powder.

The following takes NdFeB powder (NdFeB powder) as an example, the specific operation steps are as follows:

Step S1 , taking the vacuum-packaged NdFeB powder, and placing the NdFeB powder on the stainless steel tray 1 through the box door 3 .

Step S2, open the gas inlet valve 8 to introduce argon, and simultaneously open the exhaust valve 6 and the switch of the oxygen meter 4; continue to introduce argon and discharge the gas in the box 9, until the oxygen content in the box 9 is reduced to below 200ppm, Close gas inlet valve 8 and exhaust valve 6

In step S3 , the vacuum-packaged NdFeB powder is disassembled through the rubber glove 2 , and the NdFeB powder is evenly spread on the stainless steel plate 1 .

Step S4, turn on the PLC controller 5, the PLC controller 5 will make feedback after receiving the feedback information (oxygen content value) of the oxygen measuring instrument 4, and control the solenoid valve 7 to open when the oxygen content in the box 9 is lower than 1000ppm, Make the air outside the box 9 enter the box 9 to increase the oxygen content in the box 9. When the oxygen content in the box 9 is greater than 1500ppm, control the solenoid valve 7 to close to prevent the air outside the box 9 from entering the box 9. Inside, the oxygen content in the box 9 is controlled within a preset range of 1000ppm-1500ppm, so that the NdFeB powder can be safely and slowly passivated at an oxygen content of 1000ppm-1500ppm.

Step S5, when the change of the oxygen content in half an hour is less than 100 ppm, it is considered that the passivation of the NdFeB powder is completed. Turn off the PLC controller 5, turn off the oxygen measuring instrument 4, and open the box door 3 to obtain the passivation-completed NdFeB powder.

Claims

1. A passivation powder device, wherein the passivation powder device comprises:

2 . The passivation powder device according to claim 1 , wherein the passivation powder device further comprises a stainless steel tray placed in the box and used for containing the powder. 3 .

3 . The passivation powder device according to claim 1 , wherein the box body comprises a front wall and a rear wall arranged opposite to each other and two side walls arranged opposite to each other, and the box door is arranged on the front wall. 4 . The glove operation hole is arranged on one of the side walls.

4. A passivation powder method, characterized in that, the passivation powder method comprises the following steps:

Put the vacuum-packaged powder into the box through the box door;

5 . The powder passivation method according to claim 4 , wherein the opening or closing of the solenoid valve is controlled according to the feedback information to allow air to enter or prevent air from entering, and the oxygen content in the box is reduced. 6 . Controls are within preset ranges, including:

6. The powder passivation method according to claim 4 or 5, wherein the passivation powder method further comprises:

7. The powder passivation method according to claim 6, wherein the powder is NdFeB powder, the first preset value is 200 ppm, and the preset range is 1000 ppm~ 1500ppm, the second preset value is 100ppm.

8 . The powder passivation method according to claim 4 , wherein the exposing the powder in the box comprises: uniformly laying the powder in the box. 9 . in stainless steel tray.