Metal powder vacuum sintering furnace facilitating temperature control

Abstract

The utility model relates to metal processing equipment technical field discloses a kind of metal powder vacuum sintering furnace of temperature control is convenient, including vacuum furnace body, workpiece loading platform and bottom plate, workpiece loading platform lower end surface and the vacuum furnace body inner bottom surface are fixed, and the vacuum furnace body lower end surface and the bottom plate upper end surface fixed connection bottom plate upper end surface fixed connection have electric heater and pulse current generator;Vacuum furnace body inner wall surface fixed connection has three groups of heating coil pipes, and three groups of the heating coil pipe are evenly distributed along the circumferential direction of vacuum furnace body;The input end and output end of three groups of the heating coil pipe are connected with the electric heater to form independent loop by high-temperature resistant wire. The device can rapidly and uniformly heat metal powder, and optimize its sintering effect and microstructure by electric pulse treatment, improve density and mechanical properties;At the same time, real-time monitoring temperature and air pressure ensure the accurate control of sintering process, improve quality and efficiency.

Description

Technical Field

[0001] This utility model relates to the field of metal processing equipment technology, specifically to a metal powder vacuum sintering furnace that is easy to control temperature. Background Technology

[0002] With the advancement of science and technology and society, metals have become an indispensable material in people's daily lives. In the field of metal processing, various types of equipment are widely used. In particular, vacuum sintering furnaces, as a key piece of equipment, are suitable for the sintering processes of various materials such as metal powder metallurgy products, metal injection molded products, superalloys, and cemented carbides. During the sintering of metal powders, heating the powder to a specific temperature promotes the formation of bonds between powder particles, thereby producing the desired products. This process significantly improves the sintering efficiency of metal powders and the quality of the final products. However, existing metal powder vacuum sintering furnaces still have certain shortcomings, such as: The patent application CN202323431524.X, entitled "A Vacuum Sintering Furnace for Metal Powder," includes a furnace body and a first side cover and a second side cover sealed on the outer sides of its two outer walls. Supports are installed on both sides of the bottom of the furnace body. A waste gas pipe is located at the center of the outer wall of the second side cover. A circulating cooling assembly is located on the outer side of the first side cover, and an exhaust assembly is located on the outer side of the waste gas pipe. In practical applications, this device relies on only a single heating source and cannot perform specific optimization for areas with low or high temperatures, thus failing to meet usage requirements. Therefore, a vacuum sintering furnace for metal powder that facilitates temperature control is proposed to solve the above problems. Utility Model Content

[0003] The purpose of this invention is to provide a metal powder vacuum sintering furnace that is easy to control the temperature, so as to solve the problem mentioned in the background art that the existing metal powder vacuum sintering furnaces rely on only a single heating source and cannot perform specific optimization for areas with low or high temperatures.

[0004] To achieve the above objectives, this utility model provides the following technical solution: It includes a vacuum furnace body, a workpiece platform, and a base plate. The lower end face of the workpiece platform is fixed to the bottom surface of the vacuum furnace body, and the lower end face of the vacuum furnace body is fixedly connected to the upper end face of the base plate. An electric heater and a pulse current generator are fixedly connected to the upper end face of the base plate. Three sets of heating coils are fixedly connected to the inner wall of the vacuum furnace body, and the three sets of heating coils are evenly distributed along the circumference of the vacuum furnace body. The input and output ends of the three sets of heating coils are connected to the electric heater in an independent circuit via high-temperature resistant wires. A vacuum pump is fixedly connected to the upper end face of the vacuum furnace body. The output end of the vacuum pump is connected to the vacuum interface at the top of the vacuum furnace body via a metal corrugated pipe, and a vacuum sealing flange is provided at the interface.

[0005] The above technical solution facilitates rapid and uniform heating of metal powder inside the vacuum furnace.

[0006] As a preferred embodiment of this utility model, a vacuum-sealed electrode is fixedly connected to the output end of the pulse current generator, and the vacuum-sealed electrode penetrates the side wall of the vacuum furnace body; one end of the vacuum-sealed electrode is fixedly connected to the workpiece platform, and the other end of the vacuum-sealed electrode is connected to the pulse current generator; a conductive circuit corresponding to the vacuum-sealed electrode is provided inside the workpiece platform.

[0007] By adopting the above technical solution, it is convenient to perform additional electrical pulse treatment on the metal powder on the workpiece stage through a pulse current generator during the metal powder sintering process, which helps to improve the sintering effect and microstructure of the metal powder, and improve the density and mechanical properties of the sintered body.

[0008] As a preferred embodiment of this utility model, a temperature sensor is fixedly installed at the center of the inner top surface of the vacuum furnace body, and the cross-sectional dimensions of the detection area of ​​the temperature sensor match the dimensions of the bearing surface of the workpiece platform.

[0009] The above technical solution facilitates real-time monitoring of temperature changes inside the vacuum furnace, ensuring the accuracy of temperature control for metal powder during sintering and improving sintering quality.

[0010] As a preferred embodiment of this utility model, the right end face of the vacuum furnace body is rotatably connected to a furnace door via a hinge, and a sealing strip is provided on the edge of the furnace door.

[0011] By adopting the above technical solution, gas leakage inside the vacuum furnace during sintering is prevented, the vacuum level inside the furnace is ensured, and the sintering quality and efficiency are further improved.

[0012] As a preferred embodiment of this utility model, a pressure gauge is fixedly connected to the vacuum furnace body, and the pressure gauge is sealed to the vacuum interface of the vacuum furnace body through a metal bellows.

[0013] The above technical solution facilitates real-time monitoring of gas pressure changes inside the vacuum furnace.

[0014] As a preferred embodiment of this utility model, the rear end face of the electric heater is fixedly connected to a comprehensive controller, and the comprehensive controller is electrically connected to the electric heater, the pulse current generator, the temperature sensor, and the pressure gauge.

[0015] The above technical solution facilitates precise control of the entire sintering process.

[0016] Compared with the prior art, the beneficial effects of this utility model are: the device can heat the metal powder in the vacuum furnace quickly and uniformly, and at the same time, the metal powder is subjected to additional electrical pulse treatment by the pulse current generator, which effectively improves the sintering effect and microstructure of the metal powder, and improves the density and mechanical properties of the sintered body; in addition, the real-time monitoring by the temperature sensor and the pressure gauge ensures the temperature control accuracy and vacuum degree in the furnace during the sintering process, further improving the sintering quality and efficiency.

[0017] 1. During use, the operator opens the furnace door and places the workpiece to be processed inside the workpiece carrier (a ceramic insulating gasket is installed on the lower end face of the workpiece carrier to prevent pulse current leakage through the furnace body and ensure that the current acts efficiently on the metal powder). Then, the operator closes the furnace door and locks it tightly using the locking mechanism on the furnace door. The vacuum pump is then started, and it begins to work, extracting air from the vacuum furnace body through the vacuum interface until the set vacuum level is reached (if the vacuum level drops below the set range during heating, the vacuum pump will automatically replenish the vacuum). Then, the electric heater is started, and the electric heater simultaneously activates the three sets of heating coils inside the vacuum furnace body. The heating coils heat up rapidly, heating the inside of the vacuum furnace body to the preset temperature. 2. During the metal powder processing, temperature sensors (with built-in auxiliary sensors corresponding to different positions on the workpiece stage, and each auxiliary sensor corresponding to one of the three sets of heating coils) monitor the metal powder in the workpiece stage in real time to ensure that the temperature during the sintering process is always kept within the preset range. When the temperature sensor detects that the local temperature of the metal powder is low, it sends a signal to the integrated controller. The integrated controller controls the electric heater to increase the power of the heating coil in the low-temperature area, thereby increasing the temperature in that area and ensuring the temperature uniformity throughout the sintering process. 3. After the electric heater heats the interior of the vacuum furnace to the preset temperature and stabilizes for three minutes, the pulse current generator is activated (the output parameters of the pulse current are matched with the current temperature stage; the integrated controller will automatically reduce the power of the heating plate in the corresponding area according to the heat generated by the pulse current to avoid local overheating caused by the accumulation of heat). The pulse current generator (a common device in existing technology) starts working, emitting pulse current to the workpiece stage inside the vacuum furnace through the vacuum-sealed electrode to assist in heating the metal powder and enhance the sintering effect of the metal powder. The pulse current not only improves the sintering efficiency but also makes the microstructure of the metal powder more compact, improving the performance of the sintered workpiece. When the sintering process reaches the predetermined time, the integrated controller automatically stops the electric heater and the pulse current generator, allowing the metal powder in the workpiece stage to gradually cool down to room temperature. After cooling is complete, the operator opens the furnace door again and removes the sintered workpiece. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the connection structure between the vacuum furnace body and the vacuum pump of this utility model; Figure 2 This is a schematic diagram of the connection structure between the workpiece stage and the temperature sensor of this utility model; Figure 3 This is a top view of the structure of this utility model; Figure 4 This is a three-dimensional structural diagram of the heating coil of this utility model; Figure 5 This is a schematic diagram of the base plate and pulse current generator of this utility model.

[0019] In the diagram: 1. Vacuum furnace body; 2. Workpiece platform; 3. Base plate; 4. Electric heater; 5. Pulse current generator; 6. Heating coil; 7. Vacuum pump; 8. Vacuum sealing electrode; 9. Temperature sensor; 10. Furnace door; 11. Pressure gauge. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figures 1-5 The present invention provides a temperature-controlled vacuum sintering furnace for metal powder, comprising a vacuum furnace body 1, a workpiece platform 2, and a base plate 3. The lower end face of the workpiece platform 2 is fixed to the inner bottom surface of the vacuum furnace body 1, and the lower end face of the vacuum furnace body 1 is fixedly connected to the upper end face of the base plate 3. An electric heater 4 and a pulse current generator 5 are fixedly connected to the upper end face of the base plate 3. Three sets of heating coils 6 are fixedly connected to the inner wall of the vacuum furnace body 1, and the three sets of heating coils 6 are evenly distributed along the circumference of the vacuum furnace body 1. The input and output ends of the three sets of heating coils 6 are connected to the electric heater 4 through high-temperature resistant wires to form independent circuits. A vacuum pump 7 is fixedly connected to the upper end face of the vacuum furnace body 1. The output end of the vacuum pump 7 is connected to the vacuum interface at the top of the vacuum furnace body 1 through a metal bellows, and a vacuum sealing flange is provided at the interface to facilitate rapid and uniform heating of the metal powder inside the vacuum furnace body 1. A vacuum-sealed electrode 8 is fixedly connected to the output end of the pulse current generator 5, and the vacuum-sealed electrode 8 penetrates the side wall of the vacuum furnace body 1; one end of the vacuum-sealed electrode 8 is fixedly connected to the workpiece stage 2, and the other end of the vacuum-sealed electrode 8 is connected to the pulse current generator 5; a conductive circuit corresponding to the vacuum-sealed electrode 8 is set in the workpiece stage 2, which facilitates additional electrical pulse treatment of the metal powder on the workpiece stage 2 by the pulse current generator 5 during the metal powder sintering process, which helps to improve the sintering effect and microstructure of the metal powder, and improve the density and mechanical properties of the sintered body; A temperature sensor 9 is fixedly installed at the center of the inner top surface of the vacuum furnace body 1, and the cross-sectional size of the detection area of ​​the temperature sensor 9 matches the bearing surface size of the workpiece stage 2, which facilitates real-time monitoring of temperature changes inside the vacuum furnace body 1, ensures the temperature control accuracy of metal powder during the sintering process, and improves the sintering quality. The right end face of the vacuum furnace body 1 is connected to the furnace door 10 by a hinge, and the edge of the furnace door 10 is equipped with a sealing strip to prevent gas leakage in the vacuum furnace body 1 during sintering, ensure the vacuum degree in the furnace, and further improve the sintering quality and efficiency. A pressure gauge 11 is fixedly connected to the vacuum furnace body 1, and the pressure gauge 11 is sealed to the vacuum interface of the vacuum furnace body 1 through a metal bellows, so as to facilitate real-time monitoring of pressure changes inside the vacuum furnace body 1. The rear end face of the electric heater 4 is fixedly connected to the integrated controller, and the integrated controller is electrically connected to the electric heater 4, the pulse current generator 5, the temperature sensor 9, and the pressure gauge 11 respectively, so as to facilitate precise control of the entire sintering process. Working principle: During use, the operator opens the furnace door 10 and places the workpiece to be processed into the workpiece carrier 2 (a ceramic insulating gasket is installed on the lower end face of the workpiece carrier 2 to prevent pulse current leakage through the furnace body and ensure that the current acts efficiently on the metal powder). Then, the operator closes the furnace door 10 and locks it tightly through the locking mechanism on the furnace door 10. The vacuum pump 7 is then started, and the vacuum pump 7 begins to work, extracting the air from the vacuum furnace body 1 through the vacuum interface until the set vacuum degree is reached (if the vacuum degree drops beyond the set range during heating, the vacuum pump 7 will automatically replenish the vacuum). Then, the electric heater 4 is started, and the electric heater 4 simultaneously starts the three sets of heating coils 6 inside the vacuum furnace body 1. The heating coils 6 heat up rapidly, heating the inside of the vacuum furnace body 1 to the preset temperature. During the metal powder processing, temperature sensor 9 (with built-in auxiliary sensors corresponding to different positions on the workpiece stage 2, and the auxiliary sensors corresponding one-to-one with the three sets of heating coils 6) monitors the metal powder in the workpiece stage 2 in real time to ensure that the temperature during the sintering process is always kept within the preset range. When temperature sensor 9 detects that the local temperature of the metal powder is low, it sends a signal to the integrated controller. The integrated controller controls the electric heater 4 to increase the power of the heating coils 6 in the low-temperature area, thereby increasing the temperature in that area and ensuring the temperature uniformity throughout the sintering process. After the electric heater 4 heats the interior of the vacuum furnace 1 to the preset temperature and stabilizes it for three minutes, the pulse current generator 5 is started (the output parameters of the pulse current are matched with the current temperature stage, and the integrated controller will automatically reduce the power of the heating coil 6 in the corresponding area according to the heat generated by the pulse current to avoid local overheating caused by the accumulation of heat). The pulse current generator 5 (the pulse current generator 5 is a common device in the prior art) starts to work, and emits pulse current to the workpiece stage 2 in the vacuum furnace 1 through the vacuum sealed electrode 8 to assist in heating the metal powder and enhance the sintering effect of the metal powder. The pulse current can not only improve the sintering efficiency, but also make the microstructure of the metal powder more compact and improve the performance of the sintered workpiece. When the sintering process reaches the predetermined time, the integrated controller automatically stops the electric heater 4 and the pulse current generator 5, so that the metal powder in the workpiece stage 2 gradually cools down to room temperature. After cooling is completed, the operator opens the furnace door 10 again and takes out the sintered workpiece.

[0022] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A temperature-controlled vacuum sintering furnace for metal powder, comprising a vacuum furnace body (1), a workpiece platform (2), and a base plate (3), wherein the lower end face of the workpiece platform (2) is fixed to the inner bottom surface of the vacuum furnace body (1), and the lower end face of the vacuum furnace body (1) is fixedly connected to the upper end face of the base plate (3), characterized in that: An electric heater (4) and a pulse current generator (5) are fixedly connected to the upper end face of the base plate (3); three sets of heating coils (6) are fixedly connected to the inner wall of the vacuum furnace body (1), and the three sets of heating coils (6) are evenly distributed along the circumference of the vacuum furnace body (1); the input and output ends of the three sets of heating coils (6) are connected to the electric heater (4) through high temperature resistant wires to form an independent circuit; a vacuum pump (7) is fixedly connected to the upper end face of the vacuum furnace body (1); the output end of the vacuum pump (7) is connected to the vacuum interface at the top of the vacuum furnace body (1) through a metal bellows, and a vacuum sealing flange is provided at the interface.

2. The metal powder vacuum sintering furnace with easy temperature control according to claim 1, characterized in that: The output end of the pulse current generator (5) is fixedly connected to a vacuum sealing electrode (8), and the vacuum sealing electrode (8) penetrates the side wall of the vacuum furnace body (1); one end of the vacuum sealing electrode (8) is fixedly connected to the workpiece platform (2), and the other end of the vacuum sealing electrode (8) is connected to the pulse current generator (5); a conductive circuit corresponding to the vacuum sealing electrode (8) is provided inside the workpiece platform (2).

3. The metal powder vacuum sintering furnace with easy temperature control according to claim 2, characterized in that: A temperature sensor (9) is fixedly installed at the center of the inner top surface of the vacuum furnace body (1), and the cross-sectional dimension of the detection area of ​​the temperature sensor (9) matches the bearing surface dimension of the workpiece stage (2).

4. A vacuum sintering furnace for metal powder with easy temperature control according to claim 3, characterized in that: The right end face of the vacuum furnace body (1) is connected to the furnace door (10) by a hinge, and the edge of the furnace door (10) is provided with a sealing strip.

5. A vacuum sintering furnace for metal powder with easy temperature control according to claim 4, characterized in that: A pressure gauge (11) is fixedly connected to the vacuum furnace body (1), and the pressure gauge (11) is sealed to the vacuum interface of the vacuum furnace body (1) through a metal bellows.

6. A vacuum sintering furnace for metal powder with easy temperature control according to claim 5, characterized in that: The electric heater (4) is fixedly connected to the integrated controller at its rear end, and the integrated controller is electrically connected to the electric heater (4), the pulse current generator (5), the temperature sensor (9), and the air pressure gauge (11).

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