CN110577399B - Multi-field coupling flash sintering system based on induction heating - Google Patents

Multi-field coupling flash sintering system based on induction heating Download PDF

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CN110577399B
CN110577399B CN201910630762.2A CN201910630762A CN110577399B CN 110577399 B CN110577399 B CN 110577399B CN 201910630762 A CN201910630762 A CN 201910630762A CN 110577399 B CN110577399 B CN 110577399B
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flash sintering
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CN110577399A (en
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张新房
梁艺涵
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University of Science and Technology Beijing USTB
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/003Apparatus, e.g. furnaces
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10Sintering only
    • B22F3/105Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding
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    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
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    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/56Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides
    • C04B35/5607Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides based on refractory metal carbides
    • C04B35/5626Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides based on refractory metal carbides based on tungsten carbides
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    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10Sintering only
    • B22F3/105Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding
    • B22F2003/1053Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding by induction

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Abstract

The invention relates to a multi-field coupling flash sintering system based on induction heating, and belongs to the technical field of powder metallurgy. The system comprises an induction heating module, a pressurizing module, a temperature measuring module, a temperature control module, a power supply module, a mold and an electrode. The invention provides a novel non-traditional induction heating-based short-flow multi-field coupling flash sintering technology, which has the characteristics of high electric energy utilization rate, simplicity in operation, low cost, convenience in pressurization, rapid temperature rise, wide range of sinterable materials and the like.

Description

Multi-field coupling flash sintering system based on induction heating
Technical Field
The invention belongs to the technical field of powder metallurgy, and particularly relates to a multi-field coupling flash sintering system based on induction heating.
Technical Field
With the development of new powder metallurgy technology, various field-assisted sintering methods have been applied to the preparation of advanced materials in the key fields of military industry, aerospace and the like. Numerous studies have shown that field-assisted sintering processes can produce higher levels of densification in shorter times, at lower temperatures, and that materials prepared using these processes have superior properties compared to conventional techniques. The most commercialized of the field-assisted processes are spark plasma sintering and microwave sintering techniques, and a large number of related studies and patents indicate that both processes can accomplish the preparation of various metal, metal-based, ceramic materials in a shorter time and at lower temperatures.
The latest field-assisted sintering technology, flash sintering, is an ultra-fast preparation technology for materials with negative temperature coefficients, such as ceramics, which is firstly proposed in 2010, and the core of the technology is as follows: the ceramic powder blank is directly exposed to an electric field for heating, after a critical electric field and a critical temperature are reached, along with nonlinear rapid increase of material conductivity, power density reaches a peak value instantly, the ceramic is subjected to flash sintering, high-level densification is realized within a very short time scale, and the flash sintering time is between several seconds and several minutes. In a very wide range of materials, the critical electric field intensity for flash sintering is generally 7.5-1000V/cm, and the power density is generally 10-1000 mW/mm3. Flash sintering has great advantages in sintering temperature and sintering time, and has good microstructure regulation and control capability for specific materials. In addition to ceramic materials, foreign researchers have proposed a method for making electrically conductive ceramics (e.g., ZrB)2WC, etc.), metals and metal-based materials, named flash spark plasma sintering, which is characterized by directly sandwiching a sample having a certain strength after pre-sintering between electrodes and directly electrifying instead of a graphite grinding tool in the conventional spark plasma sintering equipment. The treatment can maximize the utilization rate of electric energy, and avoid the consumption of the graphite mold to the electric energy, thereby greatly shortening the sintering time and having the characteristic of flash sintering.
Based on the great potential and application background of the flash sintering technology in the preparation of various advanced materials, domestic and foreign scholars are also in active research and related patents are applied successively. The connotation, operation method and related equipment of flash sintering of ceramic materials are described in detail in patents (US9334194B2, US8940220B2) in the teaching of flash sintering proposer Raj and co-workers thereof; the patent (EP2691551B1) reports a method for manufacturing complex-shaped parts based on flash sintering technology; patent (JP5562857B2) reports a method for preparing dense iodoapatite based on flash sintering technique; patent (US9212424B1) reports a method of flash sintering by flame heating; the patent (US20150329430a1) reports a process for the preparation of multilayer ceramics based on flash sintering technology; the patent (CN108558398A) reports a method for pulse discharge room temperature flash sintering of nano ceramic material.
At present, two types of flash sintering devices are mainly adopted in related researches and patents at home and abroad, the first type adopts a platinum wire to hang a dog-bone-shaped sample in a furnace, and the sample is heated by heat radiation in the furnace. The second type uses a modified thermal dilatometer to sinter the cylindrical sheet, again using thermal radiation to heat the sample. The two types of flash sintering devices have the problems of slow heating rate (5-10 ℃/min), long flash sintering starting time, low heat utilization rate, expensive platinum electrode, difficulty in introducing pressure and the like. Many materials undergo grain growth during preheating and are not suitable for the preparation of nano ceramic materials. In addition, in the conventional flash sintering device, due to the difficulty in providing pressure, the electrode and the sample surface have large contact resistance, which results in energy dissipation and non-uniform sample temperature. In order to reduce the contact resistance, expensive conductive silver paste or platinum paste is coated on the surface of the sintered body and calcined together with the electrode. And because there is not the mould to support usually in the traditional flash sintering device, the ceramic green compact need mix the binder (usually for organic matter such as polyvinyl alcohol) and burn in a certain time (1 ~ 2h) binder removal and form certain inter-particle sintering neck at about 500 ℃ to obtain certain intensity, otherwise easily damage in connection electrode or other experimental preparation processes. However, the above pretreatment process usually causes sample contamination (incomplete binder removal, conductive paste diffusion) and grain growth, and the process flow becomes complicated, so that all the advantages of the flash sintering technology cannot be exerted.
Disclosure of Invention
The invention aims to provide a novel non-traditional flash sintering technology based on induction heating, short flow and multi-field coupling, which has the characteristics of high electric energy utilization rate, simple operation, low cost, convenient pressurization, rapid temperature rise, wide range of sinterable materials and the like by combining the characteristics of equipment, process flow, physical parameters and the like in the flash sintering method adopted in relevant research and patents at home and abroad at present and the problems existing in the equipment, the process flow, the physical parameters and the like.
According to the invention, the multi-field coupling flash sintering system based on induction heating is provided, the system utilizes the induction heating module to rapidly heat up so that the ceramic green body rapidly reaches the flash sintering starting temperature, and the coupling of the pressure field provides multiple sintering driving force, thereby further reducing the sintering time, reducing the sintering temperature and improving the densification level; the high-power supply and the die with metal inside insulation and metal outside are utilized to realize the flash sintering of the metal or metal-based composite material with better room-temperature conductivity, the system comprises a shell and a cavity, and the cavity comprises:
the induction heating module is used for heating the sintered body through conduction heat transfer to enable the sintered body to quickly reach the starting temperature of flash sintering;
a pressurizing module for applying pressure to the electrode and the sintered body;
the temperature measuring module is used for monitoring the temperature of the sintered body;
the temperature control module is used for adjusting the induction heating module according to the monitoring result of the temperature measuring system,
the power supply module is used for supplying power;
a mold for molding the sintered body;
and electrodes positioned on both sides of the sintered body.
Further, the electrode is a magnetic carbon steel, tungsten electrode, molybdenum electrode, tungsten copper alloy, stainless steel electrode, high-purity graphite, silicon carbide or hard alloy electrode.
Furthermore, the mold is internally made of a quartz tube or alumina tube insulating material, and the mold is externally made of metal.
Furthermore, the temperature measuring module adopts a thermocouple for temperature measurement and a radiation thermometer for temperature measurement.
Furthermore, the temperature measuring module adopts direct contact type temperature measurement of a filament type S-shaped thermocouple or adopts non-contact type temperature measurement of a radiation temperature measuring instrument matched with a high-purity quartz mold.
Further, the power module is a direct current power supply, an alternating current power supply or a pulse direct current power supply.
Further, the cavity is vacuumized or filled with H according to actual needs2、O2Or N2
Further, the induction heating module adjusts parameters such as the number of turns, the shape, the diameter and the power of the induction heating coil according to the heating rate, the heating temperature, the heating distance and the like required during sintering.
Further, the pressure module is a pressurizing device with a constant load function.
Further, the dimensions of the electrode and the die are designed according to the size of the sintered material, the size of the induction coil and the power of the induction heating device.
Further, the system applies a constant pressure value during flash sintering.
Further, the system applies a constant pressure value in the range of 20-50MPa during flash sintering
Furthermore, the system is mainly used for flash sintering of oxide ceramic materials based on a multi-field coupling flash sintering technology of induction heating, and can also be used for flash sintering of materials with good room-temperature conductivity, such as metal or metal-based composite materials, and the like by selecting different modules of the equipment. And flash sintering of different types of materials is realized by flexibly selecting and using equipment modules. The ceramic green body is quickly heated by the induction heating module to reach the flash sintering starting temperature, so that the problems of slow heat transfer, long preheating time, complex operation flow, high cost and the like in the traditional ceramic flash sintering equipment are solved, and meanwhile, the coupling of a pressure field provides multiple sintering driving force, so that the sintering time can be further reduced, the sintering temperature is reduced, and the densification level is improved; the flash sintering of materials with good room temperature conductivity, such as metal or metal matrix composite materials, is realized by utilizing a high-power supply, an internal insulation (alumina ceramic) and a metal (stainless steel) mold outside.
Furthermore, the system utilizes the characteristic that the induction heating module is efficient and rapid in temperature rise, the sintered body is heated through conduction heat transfer, the temperature of the sintered body can reach the starting temperature of flash sintering rapidly, the electrode temperature rise rate is determined according to the size and the power of the induction coil, and the maximum temperature rise rate can reach 1000-2000 ℃/s. Aiming at the flash sintering of the metal oxide ceramic material, an induction heating module is adopted; aiming at the flash sintering of the material with good room temperature conductivity, an induction heating module is not needed. The flash sintering of metal or metal-based composite materials and other materials with better room-temperature conductivity can be realized by adopting a high-power supply, an internal insulation (alumina ceramic) and a metal (stainless steel) mold outside.
Further, for flash sintering of the metal oxide ceramic material, the system electrode is made of carbon steel or other materials capable of rapidly increasing the temperature in the induction coil; aiming at the flash sintering of materials with good room temperature conductivity, the electrodes are made of high-purity graphite, silicon carbide or hard alloy. No conductive paste needs to be introduced between the electrode and the sintered body.
Furthermore, the system aims at the flash sintering of the metal oxide ceramic material, and the die adopts insulating materials with good high-temperature dielectric strength, such as high-purity alumina or high-purity quartz and the like; aiming at the flash sintering of the material with good room temperature conductivity, a die with the inside made of high-temperature resistant insulating material (alumina ceramic) and the outside made of high-temperature resistant metal (stainless steel) is adopted.
Further, the system can measure the temperature in two ways aiming at the flash sintering of the metal oxide ceramic material. The first one is direct contact temperature measurement with filament type S (platinum-rhodium) thermocouple; and the second non-contact temperature measurement adopts a radiation temperature measuring instrument matched with a high-purity quartz mold.
Furthermore, according to the actual operation requirements of different materials, the system can select an induction heating module, a pressure module, a power supply and other modules, wherein the power supply can select a direct current power supply, an alternating current power supply, a pulse direct current power supply and the like.
The invention has the beneficial effects that:
the invention not only overcomes the defects of slow temperature rise, low efficiency, expensive electrode, complex process flow and the like in the traditional flash sintering device, but also has the advantages of flexible operation, low cost, wide range of sintering materials and the like. In addition, the introduction of the pressure field also provides an additional sintering driving force, the flash sintering temperature and time can be further reduced, and the method is very suitable for preparing various advanced materials, such as nano ceramic materials, nano metal materials, multiphase composite materials and the like.
Drawings
FIG. 1 is a schematic diagram of an apparatus and a connection method of modules according to the present invention;
FIG. 2 is a die used in the present invention for flash sintering of good conductors;
FIG. 3 shows CeO according to the present invention2Typical flash sintering curve of ceramics;
FIG. 4 shows CeO according to the present invention2A picture of a ceramic flash sintered sample;
FIG. 5 shows CeO according to the present invention2Flash sintering the microstructure of the sample;
FIG. 6 is a photograph and microstructure of a flash-sintered sample of Al-12Si alloy according to the present invention;
FIG. 7 is a photograph and microstructure of a flash sintered sample of a high speed steel titanium carbide composite material in accordance with the present invention;
fig. 8 is a photograph and microstructure of a flash sintered sample of high purity tungsten carbide according to the present invention.
Detailed Description
The present invention is further illustrated by the following examples, but is not limited thereto.
The following examples contain flash sintering of oxide ceramics, metallic materials, metal matrix composites, metal carbides based on the present invention.
The cavity disclosed by the invention is shown in figure 1 and comprises modules such as an induction heating system, a temperature measuring and controlling system, a pressurizing system, a power supply and the like, a sintered body is heated by conduction heat transfer by utilizing the characteristic of high-efficiency and high-speed temperature rise of induction heating, so that the temperature of the sintered body can reach the starting temperature of flash sintering quickly, and the electrode temperature rise rate is determined according to the size and power of an induction coil and can reach 1000-2000 ℃/s at most. The electrode is made of magnetic carbon steel or other metal materials, the furnace temperature is higher than 1000 ℃, a graphite electrode is adopted, and the ceramic green body is quickly preheated by utilizing the characteristic of ultra-quick temperature rise of induction heating. The high-efficiency conduction heat transfer mode is adopted, the problems of slow heat transfer, long preheating time and the like in the traditional flash sintering device are solved, meanwhile, the contact between the electrode and the sample is enhanced due to the introduction of pressure, and the contact resistance can be effectively reduced without coating conductive paste on the surface of the sample. The die is made of insulating materials such as a quartz tube or an alumina tube and the like, and provides lateral support for the green body, so that the ceramic green body can be directly used for flash sintering without too high strength, and a series of complex pretreatment processes such as glue mixing and glue discharging and the like and the growth of crystal grains in the pre-sintering process are avoided. The temperature measuring means adopts a thermocouple for measuring temperature and a radiation thermometer for measuring temperature. If the change process of the sample in the sintering process is directly observed, the quartz tube can be matched with a radiation thermodetector for non-contact temperature measurement. The power supply for providing the densification energy for flash sintering can adopt a direct current power supply and an alternating current power supply according to requirementsFor example, for flash sintering of ceramic materials, various types of power supplies can be used in combination with induction heating, and for materials with good conductivity, such as metals or metal matrix composites, ac or pulse dc power supplies with high power and high frequency are required to provide sufficient joule heat, and whether induction heating is used for assisting temperature rise can be selected according to actual conditions. Meanwhile, the cavity can be vacuumized or filled with various atmospheres such as H according to actual requirements2、O2、N2And the like.
The invention provides a connection mode and an interaction mechanism of each equipment module, as shown in figure 1. And selecting equipment modules such as an induction heating module, a pressure module, a power supply type and the like according to related requirements such as the type of materials to be sintered, the size of the sintered body, the sintering temperature, the heating rate and the like.
When sintering metal oxide ceramics and composite materials thereof, the flash firing starting temperature is generally less than 1000 ℃, an induction heating module needs to be introduced, and other modules are selected according to specific requirements; when sintering metal materials, composite materials of metals and oxides, metal carbides, metal borides, metal nitrides and composite materials of metal carbides, metal borides and metal nitrides, because of good conductivity, an induction heating system is not required to be introduced in most cases, but a certain pressure is required to be applied and a pulse direct current power supply or an alternating current power supply with larger power is required to be adopted.
When sintering metal oxide ceramics and composite materials thereof, steel electrodes or other metal electrodes with higher melting points are adopted; when sintering a material with good conductivity at room temperature, an induction heating system is not required to be introduced, but an electrode with certain high-temperature performance, such as high-purity graphite, silicon carbide or hard alloy, is required to be adopted due to the high sintering temperature (greater than 1000 ℃).
For the flash sintering of the oxide ceramic material, because the electric field applied during the sintering is larger, in order to avoid the electric energy loss caused by the current flowing from a mould, high-purity alumina ceramic and high-purity quartz with good dielectric strength at high temperature are selected; for sintering a material having good conductivity at room temperature, a mold having a high-temperature-resistant insulating material (alumina ceramic) inside and a high-temperature-resistant metal (stainless steel) outside is used, as shown in fig. 2. The die not only can make the current completely flow through the sintered body, but also can ensure the continuous application of pressure even if the internal insulating material is cracked under the action of higher pressure, and is low in cost.
In an induction heating environment, when a common thermocouple (such as a K-type thermocouple) is used for measuring temperature, the interference is large, and the temperature measurement is inaccurate. Therefore, after the inventor searches for many times, the invention obtains two more accurate modes of temperature measurement in the induction heating environment. The first is direct contact temperature measurement by adopting a filament type S-shaped thermocouple; and the second non-contact temperature measurement adopts a radiation temperature measuring instrument matched with a high-purity quartz mold. Two modes can be selected according to specific operation requirements, and the temperature can be accurately controlled by matching with the temperature control module.
According to the sintering requirements of different materials, when the oxygen partial pressure or the inert gas protection is required to be controlled, the atmosphere in the cavity can be freely selected, such as O2,H2,N2Vacuum, etc.
According to different materials, sintering sizes, densities and grain sizes, different sintering conditions are selected, for example, for flash sintering of cerium dioxide ceramic with the initial grain size of 82nm, an induction heating module, a pressure module and a direct current power supply are selected, a temperature measurement mode that a quartz tube is matched with a radiation thermometer is selected, and the electric field intensity is 100V/cm, the maximum current density is 10A/cm2And (3) carrying out flash sintering at the furnace temperature of 740 ℃ and the pressure of 5 MPa.
The induction heating module can adjust parameters such as the number of turns, shape, diameter, power and the like of the induction heating coil according to the heating rate, heating temperature, heating distance and the like required during sintering, but is not limited to any form of induction heating device and any kind of induction heating device. The pressure module generally employs a hydraulic device with a constant load function, but is not limited to any form of pressurizing means of any kind.
The power type can be selected according to the flash sintering mechanism of different materials, such as oxide ceramics, a direct current power supply is generally selected, and a pulse power supply with higher power is required for a material with good conductivity at room temperature.
The sizes (diameter and length) of the electrode and the die can be flexibly designed according to the size of a sintering material, the size of an induction coil and the power of an induction heating device, and have no fixed size requirement, such as flash sintering of an oxide ceramic wafer with the diameter of 6mm and the thickness of 1mm, and selecting a carbon steel electrode with the diameter of 6mm and the length of 40mm, an induction coil with the inner diameter of 40mm and the height of 70mm and induction heating equipment with the power of 5000W.
Example 1
The present embodiment is cerium oxide (CeO)2) The flash sintering of ceramic adopts an induction heating module, a temperature measuring and controlling module and a direct current power supply. Fig. 2 is a typical flash sintering curve based on the present invention, and fig. 3 is a photograph of a sample after flash sintering, 6mm in diameter and 1mm in thickness. The critical electric field is 100V/cm, and the maximum current density is 10A/cm2Under the condition of (1), the sudden change of current and voltage begins to appear within about 16s, and then the power reaches the peak value within a few seconds, namely the flash sintering phenomenon of the oxide ceramic occurs. After flash sintering at 740 ℃ for 3min, 5min and 7min, the microstructure is shown in fig. 4, which shows a very compact state, the original powder grain boundaries are flattened, the connection between grains is tight, almost no residual pores exist, and the grains grow up only slightly. The density is measured by an Archimedes drainage method and reaches 80 percent or more (the initial density is 50 to 60 percent).
Example 2
The embodiment is flash sintering of Al-12Si alloy, a pressurizing module and a high-voltage pulse power supply are adopted, and flash sintering of metal materials is realized by utilizing the characteristic of instantaneous discharge of the high-voltage pulse power supply. A mold having a diameter of 6mm was charged with about 0.7g of Al-12Si powder, and discharge-sintered under uniaxial pressure of 550MPa, voltage of 7000V and capacitance of 90 μ F to achieve 99% densification in a period of less than 1s, and a sample photograph and microstructure thereof are shown in FIG. 6, in which hardness is improved by more than one time as compared with a cast alloy having the same composition (cast alloy is about 64HV, flash-sintered sample >130 HV).
Example 3
The embodiment is flash sintering of a high-speed steel titanium carbide composite material (the content of titanium carbide is 30 wt.%) and adopts a pressurizing module and a high-power direct-current pulse power supply. About 1.2g of the powder was charged into a 6mm diameter die with an outer steel jacket of an inner alumina tube and sintered for about 12 seconds under a voltage of 3V, a current of 500A, a frequency of 30000HZ and continuous pressurization to obtain a 96% dense sample with an average hardness of 1100HV, and the photograph and microstructure of the sample are shown in FIG. 7.
Example 4
The embodiment is flash sintering of high-purity tungsten carbide, and adopts a pressurizing module and a high-power direct-current pulse power supply. About 1g of the powder was charged into a 10mm diameter die with an inner alumina tube and an outer steel jacket and sintered for about 10 seconds under a voltage of 3V, a current of 1000A, a frequency of 30000HZ, and continuous pressurization, to obtain a sample with 81% density and an average hardness of 1650HV, and a photograph and microstructure (fracture morphology) of the sample are shown in FIG. 8.
The above description is only for the embodiment of the present invention for flash sintering of certain specific materials, and the invention is also applicable to flash sintering of other oxide ceramics with different sizes and different types and other materials with good room temperature conductivity, and only the adjustment of the parameters is needed, but the scope of the present invention is not limited thereto, and any person skilled in the art can substitute similar materials, devices or adjust the relevant technical parameters within the technical scope of the present invention, and the technical solution and the inventive concept thereof according to the present invention should be covered by the scope of the present invention.

Claims (9)

1. A multi-field coupling flash sintering system based on induction heating is characterized in that the system utilizes an induction heating module to rapidly heat up to enable a ceramic green body sintering body to rapidly reach a flash sintering starting temperature, and simultaneously provides a multiple sintering driving force through coupling of a pressure field, so that the sintering time is shortened, the sintering temperature is reduced, and the densification level is improved; the high-power supply and the die with metal inside insulation and metal outside are utilized to realize the flash sintering of the metal or metal-based composite material with better room-temperature conductivity, the system comprises a shell and a cavity, and the cavity comprises:
the induction heating module is used for heating the sintered body through conduction heat transfer to enable the sintered body to quickly reach the starting temperature of flash sintering;
a pressurizing module for applying pressure to the electrode and the sintered body;
the temperature measuring module is used for monitoring the temperature of the sintered body;
the temperature control module is used for adjusting the induction heating module according to the monitoring result of the temperature measuring system,
the power supply module is used for supplying power;
the die is used for forming the sintered body, the inside of the die is made of a quartz tube or alumina tube insulating material, and the outside of the die is made of metal;
and electrodes positioned on both sides of the sintered body.
2. The system of claim 1, wherein the electrode is a magnetic carbon steel, tungsten electrode, molybdenum electrode, tungsten copper alloy, stainless steel electrode, high purity graphite, silicon carbide, or cemented carbide electrode.
3. The system of claim 1, wherein the thermometry module employs thermocouple thermometry and radiation thermometer thermometry.
4. The system of claim 3, wherein the thermometry module adopts direct contact type thermometry of a filament type S-thermocouple or non-contact type thermometry of a radiation thermometry instrument in cooperation with a high purity quartz mold.
5. The system of claim 1, wherein the power module is a dc power source, an ac power source, or a pulsed dc power source.
6. The system of claim 1, wherein the chamber is evacuated or vented to H as needed2、O2Or N2
7. The system of claim 1, wherein the induction heating module adjusts the number of turns, shape, diameter, and power of the induction heating coil according to a heating rate, a heating temperature, and a heating distance required for sintering.
8. The system of claim 1, wherein the system applies a constant pressure value during flash sintering.
9. The system of claim 8, wherein the system applies a constant pressure value in the range of 20-50MPa during flash sintering.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3120636A1 (en) * 2021-03-15 2022-09-16 Sintermat Method for manufacturing tungsten carbide parts and material obtained based on SPS sintering of tungsten carbide

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111981847A (en) * 2020-07-24 2020-11-24 北京科技大学 Pressure-assisted induction heating vacuum atmosphere flash sintering device
CN111947460B (en) * 2020-08-03 2022-06-21 宝钢化工湛江有限公司 Control method of heating furnace for blast furnace gas and coke oven gas mixed combustion
CN111931370B (en) * 2020-08-06 2022-08-02 天津大学 COMSOL-based ceramic insulator flash firing method
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102994852A (en) * 2012-11-26 2013-03-27 四川大学 Method for preparing WC-Co hard alloy by rapid sintering under multi-physics coupling action
CN207585354U (en) * 2017-12-04 2018-07-06 深圳大学 A kind of hot pressed sintering device based on inductive heating
CN108534553A (en) * 2017-03-02 2018-09-14 中国科学院金属研究所 The device and method of block body ceramic material is quickly prepared using high-frequency induction heating
CN109894615A (en) * 2019-04-19 2019-06-18 扬州海昌新材股份有限公司 Pulsed discharge flash sintering metal base components near-net-shape process

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016082224A (en) * 2015-09-01 2016-05-16 株式会社半導体熱研究所 Heat dissipation substrate and module for semiconductor using the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102994852A (en) * 2012-11-26 2013-03-27 四川大学 Method for preparing WC-Co hard alloy by rapid sintering under multi-physics coupling action
CN108534553A (en) * 2017-03-02 2018-09-14 中国科学院金属研究所 The device and method of block body ceramic material is quickly prepared using high-frequency induction heating
CN207585354U (en) * 2017-12-04 2018-07-06 深圳大学 A kind of hot pressed sintering device based on inductive heating
CN109894615A (en) * 2019-04-19 2019-06-18 扬州海昌新材股份有限公司 Pulsed discharge flash sintering metal base components near-net-shape process

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3120636A1 (en) * 2021-03-15 2022-09-16 Sintermat Method for manufacturing tungsten carbide parts and material obtained based on SPS sintering of tungsten carbide
WO2022195215A1 (en) * 2021-03-15 2022-09-22 Sintermat Process for manufacturing tungsten carbide parts and resulting material based on sps sintering of tungsten carbide

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