WO2021139553A1 - 一种球形非晶合金粉末制备装置与方法 - Google Patents

一种球形非晶合金粉末制备装置与方法 Download PDF

Info

Publication number
WO2021139553A1
WO2021139553A1 PCT/CN2020/140078 CN2020140078W WO2021139553A1 WO 2021139553 A1 WO2021139553 A1 WO 2021139553A1 CN 2020140078 W CN2020140078 W CN 2020140078W WO 2021139553 A1 WO2021139553 A1 WO 2021139553A1
Authority
WO
WIPO (PCT)
Prior art keywords
alloy powder
cooling
amorphous alloy
liquid
gas
Prior art date
Application number
PCT/CN2020/140078
Other languages
English (en)
French (fr)
Inventor
孟令兵
江忠民
赵同春
麻洪秋
于海琛
Original Assignee
安泰（霸州）特种粉业有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 安泰（霸州）特种粉业有限公司 filed Critical 安泰（霸州）特种粉业有限公司
Priority to JP2021548216A priority Critical patent/JP7234392B2/ja
Publication of WO2021139553A1 publication Critical patent/WO2021139553A1/zh

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C45/00—Amorphous alloys
    • C22C45/02—Amorphous alloys with iron as the major constituent
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/05—Metallic powder characterised by the size or surface area of the particles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
    • B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
    • B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/003—Making ferrous alloys making amorphous alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
    • B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
    • B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
    • B22F2009/0824—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid with a specific atomising fluid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
    • B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
    • B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
    • B22F2009/0848—Melting process before atomisation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
    • B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
    • B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
    • B22F2009/086—Cooling after atomisation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
    • B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
    • B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
    • B22F2009/086—Cooling after atomisation
    • B22F2009/0872—Cooling after atomisation by water
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
    • B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
    • B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
    • B22F2009/088—Fluid nozzles, e.g. angle, distance
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
    • B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
    • B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
    • B22F2009/0888—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid casting construction of the melt process, apparatus, intermediate reservoir, e.g. tundish, devices for temperature control
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C2200/00—Crystalline structure
    • C22C2200/02—Amorphous

Definitions

  • the invention belongs to the technical field of atomized powder making, and particularly relates to a device and method for preparing spherical amorphous alloy powder by adopting a gas atomized water cooling process.
  • Atomized powder is a powder preparation method in which a fast-moving atomizing medium (usually high-pressure water or gas) crushes the metal or alloy liquid into fine droplets, and then condenses into a solid powder. Due to the different methods of preparing the powder, the shape of the obtained powder is also quite different.
  • a fast-moving atomizing medium usually high-pressure water or gas
  • amorphous alloy products Because of its high saturation magnetic induction and high permeability, amorphous alloy products have solved the adverse effects of defects such as crystal grains, grain boundaries, dislocations, interstitial atoms, and magnetocrystalline anisotropy on soft magnetic properties. They are used to make transformers, Transformers and inductive components have excellent magnetic properties, corrosion resistance, abrasion resistance, high strength, hardness, high electrical resistivity and electrical coupling performance. At present, they have a certain production scale in the United States, Japan, Germany and other countries. , A large number of amorphous alloys gradually replaced permalloy and ferrite to the market.
  • amorphous soft magnetic powder there are two main ways to prepare amorphous soft magnetic powder: (1) strip crushing method; (2) atomization method.
  • the amorphous powder prepared by the amorphous strip crushing method is easy to pierce the insulating layer coated on the powder surface due to the many edges and corners of the powder, which limits its market expansion.
  • FIG. 2 The existing device for preparing amorphous powder by atomization method is shown in FIG. 2, which includes an atomizer 1, an air inlet pipe 2, a gas flow nozzle 3, a liquid guide pipe 4, and a melt nozzle 5.
  • One of the objectives of the present invention is to provide a device for preparing spherical amorphous alloy powder, which has strong alloy amorphous forming ability and can ensure that the formed powder has good sphericity and low oxygen content.
  • the second object of the present invention is to provide a method for preparing spherical amorphous alloy powder.
  • the spherical amorphous alloy powder prepared by the method has good sphericity and low oxygen content.
  • the prepared amorphous powder can meet the needs of high magnetic permeability and low loss amorphous powder under high frequency in electronic devices.
  • the first aspect of the present invention provides a spherical amorphous alloy powder preparation device, the preparation device comprising:
  • Gas atomizer used to use atomizing gas to break alloy melt
  • the liquid cooling device is located under the gas atomizer and arranged at the periphery of the airflow nozzle of the gas atomizer, and is used to cool the alloy powder intermediate after the gas atomizer is broken to form spherical amorphous alloy powder.
  • the preparation device further includes a catheter, which connects the tundish containing the alloy melt and the gas atomizer.
  • the upper end of the catheter is in communication with the tundish.
  • the lower end of the catheter is seated at the corresponding socket of the aerosolizer.
  • the lumen of the catheter has an inverted cone shape from top to bottom, with a cone angle of 0-15°.
  • the inner cavity of the catheter transitions from an inverted cone to a cylindrical shape from top to bottom, and the cone angle is 1-15°.
  • an air inlet pipe for passing the atomizing gas into the gas atomizer is provided on the side wall of the gas atomizer.
  • an airflow nozzle for crushing the alloy melt is provided around the alloy melt outlet at the lower part of the gas atomizer.
  • the airflow nozzle is arranged in a ring shape.
  • the direction in which the airflow nozzle sprays the airflow forms an angle of 40-50° with the vertical direction.
  • the liquid cooling device is annularly arranged on the periphery of the air flow nozzle to form an annular cooling zone for cooling the alloy powder intermediate.
  • the liquid cooling device has a cylindrical structure with double walls, and the lower bottom surface of the liquid cooling device is provided with a cooling liquid outlet for the cooling liquid to flow downward to form a cooling liquid curtain.
  • the liquid curtain forms an annular cooling zone for cooling the alloy powder intermediate.
  • the cooling liquid is water.
  • the liquid cooling device has a cylindrical structure with double walls, the space between the double walls is filled with cooling liquid, and the hollow area of the cylindrical structure is used to cool the alloy powder.
  • the annular cooling zone of the body is used to cool the alloy powder.
  • the cooling liquid is liquid nitrogen.
  • the liquid cooling device is fixed on the bottom surface of the gas atomizer.
  • the side wall of the liquid cooling device is provided with a liquid inlet pipe for injecting cooling liquid into the liquid cooling device.
  • the amorphous alloy powder is FeSiB-based amorphous alloy powder; preferably, according to mass percentage, the composition of the amorphous alloy powder includes: Si: 1-14%, B: 7-15 %, C: ⁇ 4%, Cu: ⁇ 3%, Nb: ⁇ 4%, P: ⁇ 2%, the balance is Fe and unavoidable impurities.
  • the FeSiB-based amorphous alloy powder is AP01, AP02 or AP03 alloy powder;
  • the chemical composition of the AP01 alloy powder is as follows by mass percentage: Cu: 1%, Nb: 3%, Si: 13.5%, B: 9%, Fe: the balance and unavoidable impurities;
  • the chemical composition of the AP02 alloy is as follows by mass percentage: Cu: 1%, Nb: 1%, Si: 4%, B: 9%, C: 0.3%, Fe: the balance and unavoidable impurities;
  • the chemical composition of the AP03 alloy is as follows by mass percentage: Cu: 1.2%, Si: 2%, B: 12%, P: 2%, Fe: the balance and unavoidable impurities.
  • the second aspect of the present invention provides a method for preparing spherical amorphous alloy powder, which includes the following steps:
  • the alloy powder intermediate enters the cooling zone to be cooled to obtain the spherical amorphous alloy powder.
  • step S1 the raw material is melted at a condition of 50-250° C. higher than the melting point of the raw material to obtain the alloy melt.
  • step S1 the raw material is melted under the condition of 150-200° C. higher than the melting point of the raw material to obtain the alloy melt.
  • step S2 during the atomization process, the atomizing gas pressure is 2-6Mpa; the vacuum degree during the atomization process is controlled to be less than 10Pa.
  • the inert atomizing gas is nitrogen or argon.
  • the cooling rate is 10 6 K/s or more.
  • the cooling rate is 10 6 -10 7 K/s.
  • the method for preparing spherical amorphous alloy powder is carried out by using the spherical amorphous alloy powder preparing device described in the first aspect of the present invention.
  • the third aspect of the present invention provides a spherical amorphous alloy powder.
  • the spherical amorphous alloy powder is the spherical amorphous alloy powder preparation device according to the first aspect of the present invention or the spherical amorphous alloy powder according to the second aspect of the present invention. Crystalline alloy powder prepared by the preparation method.
  • the advantage of the present invention is that by improving the structure of the atomizer, a method for preparing spherical, low-oxygen amorphous powder is found.
  • the method is simple and easy to implement, and can be modified on the basis of the original atomizer. Low cost and high efficiency.
  • the spherical, low-oxygen amorphous powder can be widely used in the field of high-frequency, miniaturized electronic devices, and has a good market prospect.
  • the spherical amorphous powder prepared by the method of the present invention has a particle size range of D50: 5-30 ⁇ m, and an oxygen content of 600 ppm or less.
  • Figure 1 is a photograph of amorphous powder prepared by strip crushing in the prior art.
  • Figure 2 is a schematic diagram of the structure of a prior art spherical amorphous alloy powder preparation device.
  • FIG. 3 is a schematic diagram of the structure of a spherical amorphous alloy powder preparation device according to some embodiments of the present invention.
  • FIG. 4 is a schematic diagram of the structure and use state of the spherical amorphous alloy powder preparation device shown in FIG. 3.
  • Figure 5 is a SEM scanning electron micrograph of the amorphous alloy powder prepared in Example 1 of the present invention.
  • Fig. 6 is an XRD pattern of the amorphous alloy powder prepared in Example 1 of the present invention.
  • Figure 7 is a SEM scanning electron micrograph of the alloy powder prepared in Comparative Example 1.
  • Figure 8 is an XRD pattern of the alloy powder prepared in Comparative Example 1.
  • Figure 9 is a SEM scanning electron micrograph of the amorphous alloy powder prepared in Example 2 of the present invention.
  • Fig. 10 is an XRD pattern of the amorphous alloy powder prepared in Example 2 of the present invention.
  • Figure 11 is a SEM scanning electron micrograph of the alloy powder prepared in Comparative Example 2.
  • Fig. 12 is an XRD pattern of the alloy powder prepared in Comparative Example 2.
  • Figure 13 is a SEM scanning electron micrograph of the amorphous alloy powder prepared in Example 3 of the present invention.
  • Example 14 is an XRD pattern of the amorphous alloy powder prepared in Example 3 of the present invention.
  • Figure 15 is a SEM scanning electron micrograph of the alloy powder prepared in Comparative Example 3 of the present invention.
  • Figure 16 is an XRD pattern of the alloy powder prepared in Comparative Example 3 of the present invention.
  • 1-gas atomizer 2-inlet pipe, 3-air nozzle, 4-liquid pipe, 5-melt nozzle, 6-water cooling device, 7-water inlet pipe, 8-alloy molten liquid flow, 9 -Sprayed atomizing gas, 10-cooling water curtain, 11-amorphous alloy powder.
  • the abscissa is 2 ⁇ (twice the incident angle of the x-ray), and the ordinate is the diffraction intensity.
  • the amorphous powder prepared by water atomization has poor sphericity and high oxygen content, and the oxygen content usually reaches about 2000 ppm.
  • the gas atomization process the sphericity and oxygen content of the powder will be improved.
  • the use of the gas atomization process will have the problem of difficulty in the formation of amorphous, especially for some larger powder particles, it is more difficult to form amorphous.
  • the present invention finds an atomized powder making device and method, which can obtain spherical, low-oxygen amorphous powder.
  • the invention combines gas atomization and cooling after gas atomization to obtain amorphous powder with low oxygen and good sphericity.
  • the prepared spherical amorphous powder has a particle size range D50: 5-30 ⁇ m and an oxygen content below 600 ppm.
  • the spherical amorphous alloy powder preparation device provided by the present invention is a simple and easy-to-implement structural modification of the existing gas atomization equipment, so that the alloy melt can be broken by the impact of high-pressure gas, and the metal droplets are formed under the action of surface tension. Spherical particles, the particles are rapidly cooled through the cooling zone formed by the cooling liquid (water) curtain, thereby obtaining spherical, low-oxygen amorphous powder.
  • the preparation device of the present invention includes a gas atomizer 1 and a liquid cooling device located below the gas atomizer 1 and arranged at the periphery of the airflow nozzle of the gas atomizer.
  • the preparation device of the present invention can also include a melting furnace for melting alloys, a tundish for holding alloy melts, a vacuum pump, equipment for providing atomizing gas, and equipment for collecting powder, such as equipment used to achieve atomization and pulverization. It belongs to the conventional equipment for atomization and milling, so it will not be repeated here. Only the parts closely related to the purpose of the present invention will be described in detail below.
  • the gas atomizer 1 uses atomizing gas to break the alloy melt from the tundish.
  • the gas atomizer 1 used in the present invention may be a conventional device used in the field of atomization and powder milling.
  • the gas atomizer 1 includes a body for inserting a corresponding socket of the catheter 4,
  • the air inlet pipe 2 for connecting atomizing gas, the airflow nozzle 3 for spraying atomizing gas, and the liquid pipe 4 are used to connect the tundish with alloy melt and the gas atomizer 1, and the pipe 4
  • the inner cavity is in an inverted cone from top to bottom, and the cone angle is 0°-15°.
  • the inner cavity of the catheter 4 transitions from an inverted cone to a cylindrical shape from top to bottom, and the cone angle of the inverted cone is 1-15° (such as 2°, 5°, 7°, 10°, 12°, 14°), the tapered structure can ensure that the alloy melt stream 8 has sufficient flow and pressure, which is conducive to gas atomization get on.
  • the airflow nozzle 3 sprays the airflow at an angle of 40-50° (such as 41°, 43°, 45°, 47°, 49°) with the vertical direction (that is, the axial direction of the catheter) to ensure the atomization system Powder effect and particle size.
  • the upper end of the catheter 4 is in communication with the tundish, and the lower end of the catheter 4 is seated on the corresponding socket of the gas atomizer 1, so that the alloy melt can be removed from the catheter
  • the bottom spout of 4 sprays out, forming a downward flow of molten alloy 8, and the inner cavity of the catheter 4 transitions from an inverted cone to a cylindrical shape from top to bottom, and the cone angle of the inverted cone is 10°.
  • the tapered structure can ensure that the alloy melt stream 8 has sufficient flow and pressure, which is beneficial to the progress of gas atomization.
  • the side wall of the gas atomizer 1 is provided with an air inlet pipe 2 for introducing the atomizing gas into the gas atomizer 1, and the alloy melt outlet (ie the bottom ejection port of the catheter 4) is surrounded at the lower part of the gas atomizer. )
  • Two airflow nozzles 3 are arranged in a ring shape, the direction of the airflow nozzle 3 sprays the airflow and the vertical direction (that is, the axial direction of the catheter) is 45°, the atomized gas entering from the air inlet pipe 2 reaches the airflow nozzle 3, and the nozzle is sprayed The discharged atomizing gas 9 breaks the alloy melt stream.
  • the liquid cooling device is located below the gas atomizer 1 and arranged at the periphery of the airflow nozzle 3 of the gas atomizer 1, and is used to cool the alloy powder intermediates crushed by the gas atomizer 1 to form spherical amorphous alloy powder.
  • the liquid cooling device of the present invention is any cooling device that can provide a sufficient cooling rate for the crushed alloy powder intermediate, for example: it can be a cooling device that can form a cooling zone surrounded by the cooling liquid sprayed from the cooling liquid outlet, and The alloy powder intermediate just passes through the cooling zone, the cooling liquid can be water, and this kind of cooling device can be a double-walled cylindrical structure with a cooling liquid outlet arranged circumferentially on the bottom surface; or a cooling made of a material with good heat transfer
  • the cooling device can be a cylindrical, quadrilateral, or hexagonal cylindrical structure.
  • the cylinder wall is double-layer hollow, and the space between the double-layer walls is filled with a cooling liquid, such as liquid nitrogen, etc.
  • the lower bottom surface of the cooling device is not provided with a cooling liquid outlet, and the area in the middle of the barrel of the cylindrical cooling device is a cooling zone for cooling the alloy powder intermediate.
  • the vertical height of the first type of cooling device forming the cooling water curtain is smaller than that of the second type of cooling device.
  • the liquid cooling device is annularly arranged on the periphery of the airflow nozzle 3, and the upper end can be fixed on the bottom surface of the gas atomizer 1, or can be installed independently of the gas atomizer 1.
  • the surface of the cylinder wall is smooth or coated with a smooth coating so that the powder particles cannot adhere to the cylinder wall.
  • the liquid cooling device is annularly arranged on the periphery of the airflow nozzle 3, and the upper end is fixed on the lower bottom surface of the gas atomizer 1.
  • the lower bottom surface of the liquid cooling device has a cooling liquid outlet.
  • Water is used, so the cooling device is also called water cooling device 6.
  • the water cooling device 6 also includes a water inlet pipe 7 for water intake, which is arranged on the side wall of the water cooling device 6 to supply cooling water to the inside of the water cooling device.
  • the cooling liquid outlet flows downwards to form an annular cooling water curtain 10.
  • the inside of the cooling water curtain 10 is a cooling zone for cooling the alloy powder intermediate to form an amorphous alloy powder 11.
  • the present invention adds an annular water-cooling device 6 below the gas atomizer.
  • the annular water-cooling device 6 is located outside the airflow nozzle 3.
  • the water-cooling device 6 can flow out or spray cooling water downward to ensure the cooling enclosed by the annular water curtain.
  • the zone has a suitable temperature, so that the alloy droplets passing through the cooling zone are cooled to form an amorphous powder.
  • the alloy melt is sprayed out through the nozzle at the bottom of the catheter 4. When the alloy melt is broken into small metal droplets by the impact of high-pressure gas, the cooling rate of the gas is much lower than that of water, so the metal droplets are on the surface.
  • Spherical powder particles are formed under the action of tension, and the powder particles pass through the cooling water curtain 10 sprayed by the annular water cooling device under the atomizer during the falling process, and the spherical particles are rapidly cooled to obtain amorphous alloy powder 11.
  • the preparation device of the present invention is suitable for preparing various amorphous alloy powders, and is particularly suitable for preparing FeSiB series amorphous alloy powders; preferably, according to mass percentage, the composition of the amorphous alloy powder includes: Si:1-14%, B: 7-15%, C: ⁇ 4%, Cu: ⁇ 3%, Nb: ⁇ 4%, P: ⁇ 2%, the balance is Fe and inevitable impurities; such as the FeSiB-based amorphous alloy powder AP01, AP02 or AP03 alloy powder; the chemical composition of the AP01 alloy powder in mass percentage is: Cu: 1%, Nb: 3%, Si: 13.5%, B: 9%, Fe: the balance and inevitable impurities The chemical composition of the AP02 alloy by mass percentage is: Cu: 1%, Nb: 1%, Si: 4%, B: 9%, C: 0.3%, Fe: the balance and unavoidable impurities; the AP03 The alloy chemical composition in mass percentage is: Cu: 1.2%, Si
  • the invention also provides a method for preparing the spherical amorphous alloy powder, which includes the following steps:
  • S1 Put the metal raw material into a vacuum intermediate frequency induction furnace and heat it to melt.
  • the temperature of the molten steel is selected according to the material; generally it is heated to 1300-1600°C, preferably 50-250°C higher than the melting point of the raw material, more preferably Melting the raw material under the condition of 150-200°C, and controlling the vacuum degree below 10 Pa (for example, 9 Pa, 7 Pa, 6 Pa, 1 Pa, 0.1 Pa) to obtain the alloy melt;
  • a suitable atomization pressure is selected according to the particle size requirements, and the atomization gas pressure (that is, the spray pressure of the gas used for atomization) is 2-6Mpa (such as 2.5Pa, 3Pa, 4Pa, 5Pa) , 5.5Pa); the vacuum degree during the atomization treatment is controlled below 10Pa (for example, 9Pa, 7Pa, 6Pa, 1Pa, 0.1Pa); the inert atomizing gas is nitrogen or argon.
  • the atomization gas pressure that is, the spray pressure of the gas used for atomization
  • the vacuum degree during the atomization treatment is controlled below 10Pa (for example, 9Pa, 7Pa, 6Pa, 1Pa, 0.1Pa)
  • the inert atomizing gas is nitrogen or argon.
  • the alloy powder intermediate enters the cooling zone for cooling to obtain the spherical amorphous alloy powder; preferably, the cooling rate is 10 6 K/s or more (for example, 2*10 6 K/s, 4*10 6 K/s, 6*10 6 K/s, 8*10 6 K/s, 9*10 6 K/s, 2*10 7 K/s, 4*10 7 K/s, 6*10 7 K/ s, 8*10 7 K/s, 9*10 7 K/s); more preferably, the cooling rate is 10 6 -10 7 K/s.
  • the following examples are used to further illustrate the preparation method of the present invention.
  • the following preparation method examples all adopt the preparation device of the present invention, in which the direction and vertical direction of the air flow from the air flow nozzle 3 (ie the axial direction of the catheter) At 45°, the inner cavity of the catheter 4 transitions from an inverted cone to a cylindrical shape from top to bottom, the cone angle of the inverted cone is 10°, the cooling liquid is water, and the liquid cooling device can form a cooling water curtain.
  • AP01 amorphous powder is prepared, and its chemical composition (calculated by mass percentage) is: Cu: 1%, Nb: 3%, Si: 13.5%, B: 9%, Fe: the balance. Elements not mentioned are unavoidable impurities.
  • the preparation method is as follows:
  • Argon is used as the atomizing gas for atomization treatment in an environment with a vacuum degree of 5 Pa to obtain a broken and spheroidized alloy powder intermediate, wherein the atomization temperature (that is, the temperature of the alloy melt in the tundish) ) Is 1320°C, and the atomizing gas pressure is 2.2Mpa;
  • the alloy powder intermediate enters the cooling zone formed by the cooling water curtain down for cooling, and the cooling rate is above 2*10 6 K/s, and finally the amorphous alloy powder is collected.
  • the alloy powder was observed by scanning electron microscope (SEM). The photo is shown in Fig. 5. It can be seen from the figure that the sphericity of the alloy powder prepared by the method of the present invention is very good, and the particle size D50: 28 ⁇ m. The oxygen content of the alloy powder is 319 ppm.
  • the XRD pattern is obtained through X-ray diffraction analysis. See Figure 6. It can be seen from the figure that the measured powder has no obvious diffraction peak and is an amorphous alloy powder.
  • This comparative example 1 uses the existing gas atomization equipment to make powder, and the raw materials and the first two steps are the same as those of the example 1, and this comparative example only omits the cooling step of step (3).
  • the alloy powder obtained in this comparative example was observed through a scanning electron microscope (SEM). See FIG. 7. It can be seen from the figure that the sphericity of the powder deteriorates due to the decrease in the cooling rate.
  • the particle size D50 is 23 ⁇ m, and the oxygen content is 613 ppm.
  • the XRD pattern was obtained by X-ray diffraction analysis, see Figure 8. It can be seen from the figure that the alloy powder prepared in this comparative example has already appeared diffraction peaks, and the powder began to crystallize.
  • AP02 amorphous alloy powder is prepared, and its chemical composition (calculated by mass percentage) is: Cu: 1%, Nb: 1%, Si: 4%, B: 9%, C: 0.3%, Fe: balance . Elements not mentioned are unavoidable impurities.
  • the preparation method is as follows:
  • Argon is used as the atomizing gas for atomization treatment in an environment with a vacuum of 8 Pa to obtain a crushed and spheroidized alloy powder intermediate, wherein the atomization temperature (that is, the temperature of the alloy melt in the tundish) ) Is 1420°C, and the atomizing gas pressure is 6Mpa;
  • the alloy powder intermediate enters the cooling zone formed by the cooling water curtain down for cooling, and the cooling rate is above 2*10 6 K/s, and finally the amorphous alloy powder is collected.
  • the alloy powder was observed through a scanning electron microscope (SEM). The photo is shown in Fig. 9. It can be seen from the figure that the alloy powder prepared by the method of the present invention has a very good sphericity and a particle size D50: 10 ⁇ m. The oxygen content of the alloy powder is 503 ppm.
  • the XRD pattern is obtained by X-ray diffraction analysis. See Fig. 10. It can be seen from the figure that the measured powder has no obvious diffraction peak, and it is an amorphous alloy powder.
  • This comparative example 2 uses the existing gas atomization equipment (ie no liquid cooling device) to make powder.
  • the raw materials and the first two steps are the same as those of the example 2, and this comparative example only omits the cooling step of step (3).
  • the alloy powder obtained in this comparative example was observed by scanning electron microscope (SEM). See Figure 11. It can be seen from the figure that due to the decrease in cooling rate, the irregular shape particles in the powder increase significantly and the sphericity becomes worse. .
  • the particle size D50 is 11 ⁇ m, and the oxygen content is 762 ppm.
  • the XRD pattern is obtained through X-ray diffraction analysis. See FIG. 12. It can be seen from the figure that the alloy powder prepared in this comparative example has already appeared diffraction peaks, and the powder has begun to crystallize.
  • AP03 amorphous alloy powder is prepared, and its chemical composition (calculated by mass percentage) is: Cu: 1.2%, Si: 2%, B: 12%, P: 2%, Fe: the balance. Elements not mentioned are unavoidable impurities.
  • the preparation method is as follows:
  • Argon is used as the atomizing gas for atomization treatment in an atmosphere with a vacuum of 3 Pa to obtain a crushed and spheroidized alloy powder intermediate, where the atomization temperature (that is, the temperature of the alloy melt in the tundish) ) Is 1380°C, and the atomizing gas pressure is 3.6Mpa;
  • the alloy powder intermediate enters the cooling zone formed by the cooling water curtain down for cooling, and the cooling rate is above 2*10 6 K/s, and finally the amorphous alloy powder is collected.
  • the alloy powder was observed through a scanning electron microscope (SEM). See FIG. 13. It can be seen from the figure that the alloy powder prepared by the method of the present invention has a very good sphericity and a particle size D50: 17 ⁇ m.
  • the oxygen content of the alloy powder is 361 ppm.
  • the XRD pattern is obtained by X-ray diffraction analysis. See Figure 14. It can be seen from the figure that the measured powder has no obvious diffraction peak and is an amorphous alloy powder.
  • This comparative example 3 uses the existing gas atomization equipment to make powder, and the raw materials and the first two steps are the same as those of the example 3.
  • This comparative example only omits the cooling step of step (3).
  • the alloy powder obtained in this comparative example was observed by scanning electron microscope (SEM). See Figure 15. It can be seen from the figure that due to the decrease in cooling rate, the irregular shape particles in the powder increase significantly and the sphericity becomes worse. .
  • the particle size D50 is 18 ⁇ m, and the oxygen content is 537 ppm.
  • the XRD pattern is obtained by X-ray diffraction analysis. See FIG. 16. It can be seen from the figure that the alloy powder prepared in this comparative example has already appeared diffraction peaks, and the powder has begun to crystallize.
  • the powder obtained in Examples 1-3 has no obvious diffraction peaks and is amorphous alloy powder, while the powder obtained in Comparative Examples 1-3 has obvious diffraction peaks, and the powder has crystallized. It can be seen that the atomized powder making device of the present invention An amorphous powder with a more uniform particle size, a more regular spherical shape and a smaller oxygen content can be obtained. In addition, the method and device of the present invention can obtain spherical amorphous powder with a relatively large size, which can improve the magnetic permeability, and is particularly suitable for the preparation of FeSiB-based amorphous alloy powder.

Abstract

本发明公开了一种球形非晶合金粉末制备装置，包括：气雾化器，用于采用雾化气体将合金熔液破碎；液冷装置，位于气雾化器下方且设置于气雾化器的气流喷嘴外围，用于将气雾化器破碎后的合金粉末中间体冷却形成球形非晶合金粉末。本发明还公开了一种球形非晶合金粉末制备方法，包括如下步骤：S1：将原料熔化，得到合金熔液；S2：在真空或惰性气氛下，采用惰性雾化气体对合金熔液进行雾化处理，得到合金粉末中间体；S3：合金粉末中间体进入冷却区进行冷却，得到球形非晶合金粉末。通过如上制备装置或制备方法制备得到粒度更均一、球形更规则、含氧量更小的球形非晶合金粉末。

Description

一种球形非晶合金粉末制备装置与方法 技术领域
本发明属于雾化制粉技术领域，特别涉及一种采用气雾化水冷工艺制备球形非晶合金粉末的装置与方法。
背景技术
雾化制粉是以快速运动的雾化介质(通常是高压的水或气)打击破碎将金属或合金液体破碎为细小液滴，继之冷凝为固体粉末的粉末制备方法。由于制取粉末的方法不同，所得到粉末的形状也大不相同。
非晶合金产品由于具有高饱和磁感应强度和高磁导率，解决了晶粒、晶界、位错、间隙原子、磁晶各向异性等缺陷对软磁性能的不利影响，用于制作变压器、互感器及电感元件等具有优异的磁性、耐蚀性、耐磨性、高的强度、硬度和高的电阻率及电耦合性能，目前在美国、日本、德国等国家都已经有一定的生产规模，大量的非晶合金逐渐取代坡莫合金及铁氧体涌向市场。随着电子器件高频化和小型化的发展，市场对高频率下高磁导率、低损耗软磁粉末的要求也日趋苛刻。因此，制备球形、低氧的非晶粉末成为解决问题的关键。
目前制备非晶软磁粉体的方式主要有两种：(1)带材破碎法；(2)雾化法。采用非晶带材破碎法制备的非晶粉由于粉末棱角多，容易刺破粉末表面包覆的绝缘层，因而限制了其市场的拓展。带材破碎法制备的非晶粉照片参见图1。现有雾化法制备非晶粉末的装置参见图2，包括雾化器1，进气管2，气流喷嘴3，导液管4，熔液喷嘴5。
发明内容
本发明的目的之一是提供一种球形非晶合金粉末的制备装置，该装置合金非晶形成能力强，而且可以保证形成的粉末具有良好的球形度和低氧量。
本发明的目的之二在于提供一种球形非晶合金粉末的制备方法，该方法制备的球形非晶合金粉末球形度好、含氧量低。制备的非晶粉末可以解决电子器件高频下对高磁导率、低损耗非晶粉末的需求。
为了实现上述目的，本发明采用如下技术方案：
本发明第一方面提供了一种球形非晶合金粉末制备装置，所述制备装置包括：
气雾化器，用于采用雾化气体将合金熔液破碎；
液冷装置，位于所述气雾化器下方且设置于所述气雾化器的气流喷嘴外围，用于将所述气雾化器破碎后的合金粉末中间体冷却形成球形非晶合金粉末。
在一些实施方式中，所述制备装置还包括导液管，连接装有所述合金熔液的中间包和所述气雾化器。
在一些实施方式中，所述导液管上端与所述中间包连通。
在一些实施方式中，所述导液管下端部座设于所述气雾化器的对应插口。
在一些实施方式中，所述导液管的内腔从上到下呈倒锥形，锥角为0-15°。
在一些实施方式中，所述导液管的内腔从上到下由倒锥形过渡为圆筒状，锥角为1-15°。
在一些实施方式中，在所述气雾化器的侧壁上设置有用于向所述气雾化器中通入所述雾化气体的进气管。
在一些实施方式中，在所述气雾化器下部围绕合金熔液出口设置有用于破碎所述合金熔液的气流喷嘴。
在一些实施方式中，所述气流喷嘴呈环形设置。
在一些实施方式中，所述气流喷嘴喷出气流的方向与竖向呈40-50°夹角。
在一些实施方式中，所述液冷装置呈环形设置于所述气流喷嘴外围，用于形成冷却所述合金粉末中间体的环形冷却区。
在一些实施方式中，所述液冷装置为具有双层壁的筒形结构，且所述液冷装置下底面设置有冷却液出口，用于冷却液向下流出形成冷却液幕，所述冷却液幕形成冷却所述合金粉末中间体的环形冷却区。
在一些实施方式中，所述冷却液为水。
在一些实施方式中，所述液冷装置为具有双层壁的筒形结构，所述双层 壁之间的空间填充有冷却液，筒形结构的中空区域是用于冷却所述合金粉末中间体的环形冷却区。
在一些实施方式中，所述冷却液为液氮。
在一些实施方式中，所述液冷装置固定于所述气雾化器的下底面上。
在一些实施方式中，所述液冷装置的侧壁上设置有用于向所述液冷装置注入冷却液的进液管。
在一些实施方式中，所述非晶合金粉末为FeSiB系非晶合金粉末；优选地，按照质量百分比，所述非晶合金粉末的组分包括：Si：1-14％、B：7-15％、C：≤4％、Cu：≤3％、Nb：≤4％、P：≤2％，余量为Fe和不可避免的杂质。
在一些实施方式中，所述FeSiB系非晶合金粉末为AP01、AP02或AP03合金粉末；
所述AP01合金粉末化学成分按质量百分比为：Cu：1％、Nb：3％、Si：13.5％、B：9％、Fe：余量以及不可避免的杂质；
所述AP02合金化学成分按质量百分比为：Cu：1％、Nb：1％、Si：4％、B：9％、C：0.3％、Fe：余量以及不可避免的杂质；
所述AP03合金化学成分按质量百分比为：Cu：1.2％、Si：2％、B：12％、P：2％、Fe：余量以及不可避免的杂质。
本发明第二方面提供了一种球形非晶合金粉末制备方法，所述制备方法包括如下步骤：
S1：将原料熔化，得到合金熔液；
S2：在真空或惰性气氛下，采用惰性雾化气体对所述合金熔液进行雾化处理，得到合金粉末中间体；
S3：所述合金粉末中间体进入冷却区进行冷却，得到所述球形非晶合金粉末。
在一些实施方式中，在步骤S1中，在高于所述原料熔点50～250℃的条件下将所述原料熔化，得到所述合金熔液。
在一些实施方式中，在步骤S1中，在高于所述原料的熔点150～200℃的条件下将所述原料熔化，得到所述合金熔液。
在一些实施方式中，在步骤S2中，所述雾化处理时，雾化气体压力为2～6Mpa；所述雾化处理时的真空度控制10Pa以下。
在一些实施方式中，在步骤S2中，所述惰性雾化气体为氮气或氩气。
在一些实施方式中，在步骤S3中，所述冷却的速率为10 6K/s以上。
在一些实施方式中，所述冷却的速率为10 6-10 7K/s。
在一些实施方式中，所述球形非晶合金粉末制备方法是使用本发明第一方面所述的球形非晶合金粉末制备装置进行的。
本发明第三方面提供了一种球形非晶合金粉末，所述球形非晶合金粉末是根据本发明第一方面所述的球形非晶合金粉末制备装置或本发明第二方面所述的球形非晶合金粉末制备方法制备得到的。
本发明制备装置的技术特征可以以任何可能的方式组合使用。
本发明的优点在于，通过对雾化器结构进行改进，找到了一种制备球形、低氧非晶粉末的方法，该方法简单易行，而且可以在原有雾化器的基础上进行结构改造，成本低、效率高。球形、低氧的非晶粉末可以广泛应用于高频、小型化的电子器件领域，具有良好的市场前景。本发明方法制备得到的球形非晶粉末的粒度范围D50:5～30μm，氧含量600ppm以下。
附图说明
图1为现有技术中带材破碎法制备的非晶粉照片。
图2为现有技术球形非晶合金粉末制备装置结构示意图。
图3为本发明一些实施例的球形非晶合金粉末制备装置结构示意图。
图4为图3所示球形非晶合金粉末制备装置结构与使用状态示意图。
图5为本发明实施例1制备的非晶合金粉末的SEM扫描电镜照片。
图6为本发明实施例1制备的非晶合金粉末的XRD图谱。
图7为对比例1制备的合金粉末的SEM扫描电镜照片。
图8为对比例1制备的合金粉末的XRD图谱。
图9为本发明实施例2制备的非晶合金粉末的SEM扫描电镜照片。
图10为本发明实施例2制备的非晶合金粉末的XRD图谱。
图11为对比例2制备的合金粉末的SEM扫描电镜照片。
图12为对比例2制备的合金粉末的XRD图谱。
图13为本发明实施例3制备的非晶合金粉末的SEM扫描电镜照片。
图14为本发明实施例3制备的非晶合金粉末的XRD图谱。
图15为本发明对比例3制备的合金粉末的SEM扫描电镜照片。
图16为本发明对比例3制备的合金粉末的XRD图谱。
其中，1-气雾化器，2-进气管，3-气流喷嘴，4-导液管，5-熔液喷嘴，6-水冷装置，7-进水管，8-合金熔液液流，9-喷出的雾化气体，10-冷却水幕，11-非晶合金粉末。
图6、8、10、12、14、16的XRD图谱中横坐标为2θ(x射线的入射角度的两倍)，纵坐标为衍射强度。
具体实施方式
为使本发明的目的、技术方案和优点更加清楚，下面将结合附图对本发明装置和方法作进一步地详细描述。
目前水雾化制备的非晶粉末球形度较差、氧含量偏高，通常氧含量会达到2000ppm左右。采用气雾化工艺，粉末的球形度和氧含量都会得到改善，但是，采用气雾化工艺会存在非晶形成困难的问题，尤其是一些尺寸较大的粉末颗粒，形成非晶更加困难。本发明找到了一种雾化制粉装置和方法，能够获得球形、低氧的非晶粉末。本发明将气雾化和气雾化后的冷却结合起来，可以得到低氧、球形度好的非晶粉末，制备得到的球形非晶粉末的粒度范围D50:5～30μm，氧含量600ppm以下。
本发明提供的球形非晶合金粉末制备装置，是通过对现有气雾化设备进行简单易实施的结构改造，可以使合金熔液经过高压气体打击破碎，金属液滴在表面张力的作用下形成球形颗粒，颗粒经过冷却液(水)幕形成的冷却区快速冷却，从而获得球形、低氧的非晶粉末。参见图2-4，本发明的制备装置包括气雾化器1和位于气雾化器1下方且设置于所述气雾化器的气流喷嘴外围的液冷装置，当然，本发明的制备装置还可以包括用于熔化合金的熔化炉、盛放合金熔液的中间包、真空泵、提供雾化气体的设备、收集粉末的集料设备等用于实现雾化制粉的设备，由于这些设备都属于雾化制粉的常规设备，所以在此不再一一赘述，下面仅对与实现本发明目的密切相关的部分进行详细说明。
气雾化器1，采用雾化气体将来自中间包的合金熔液破碎。本发明使用的气雾化器1可以是雾化制粉领域使用的常规设备，在本发明的实施方式中， 气雾化器1包括：本体，用于插接导液管4的对应插口，用于接入雾化气体的进气管2，用于喷出雾化气体的气流喷嘴3，导液管4用于连接装有合金熔液的中间包和气雾化器1，导液管4的内腔从上到下呈倒锥形，锥角为0°-15°，优选地，导液管4的内腔从上到下由倒锥形过渡为圆筒状，倒锥形的锥角为1-15°(比如2°、5°、7°、10°、12°、14°)，该锥形结构可以保证合金熔液液流8具有足够的流量和压力，利于气雾化的进行。气流喷嘴3喷出气流的方向与竖向(即导液管的轴向)呈40-50°(比如41°、43°、45°、47°、49°)夹角，以保证雾化制粉效果和粒度。
在本发明优选的实施例中，导液管4的上端与中间包连通，导液管4的下端部座设于气雾化器1的对应插口，由此，合金熔液可以从导液管4的底部喷出口喷出，形成向下的合金熔液液流8，导液管4的内腔从上到下由倒锥形过渡为圆筒状，倒锥形的锥角为10°，该锥形结构可以保证合金熔液液流8具有足够的流量和压力，利于气雾化的进行。气雾化器1的侧壁上设置有用于向气雾化器1中通入雾化气体的进气管2，在气雾化器下部围绕合金熔液出口(即导液管4的底部喷出口)设置有用于破碎合金熔液液流8的气流喷嘴3，也可以说，气流喷嘴3为多个，均匀设置于气雾化器1的下底面且围绕导液管4的底部喷出口，多个气流喷嘴3呈环形设置，气流喷嘴3喷出气流的方向与竖向(即导液管的轴向)呈45°，由进气管2进入的雾化气体达到气流喷嘴3，由该喷嘴喷出的雾化气体9将合金熔液液流破碎。
液冷装置，位于气雾化器1下方且设置于气雾化器1的气流喷嘴3的外围，用于将气雾化器1破碎后的合金粉末中间体冷却形成球形非晶合金粉末。本发明的液冷装置是可以为破碎后的合金粉末中间体提供足够冷却速度的任何冷却装置，比如：可以是能够形成由冷却液出口喷出的冷却液体围成的冷却区的冷却装置，而合金粉末中间体恰好经过该冷却区，冷却液可以是水，该种冷却装置可以是下底面周向设置冷却液出口的双层壁筒形结构；或者是由具有良好传热材质制成的冷却装置，该冷却装置可以是圆筒形或四边形筒或六边形筒等筒形结构，筒壁是双层中空的，双层壁之间的空间内填充有冷却液，比如液氮等，该种冷却装置的下底面不设置冷却液出口，该圆筒形冷却装置的筒中间的区域即是用于冷却合金粉末中间体的冷却区。第一种形成冷却水幕的冷却装置的竖向高度小于第二种冷却装置。液冷装置呈环形设置 于气流喷嘴3外围，上端可以固定于气雾化器1的下底面上，也可以独立于气雾化器1设置。优选，筒壁表面是光滑的或涂覆有光滑涂层，以便使粉末颗粒不能粘连在筒壁上。
在本发明的某一优选实施例中，液冷装置呈环形设置于气流喷嘴3外围，上端固定于气雾化器1的下底面上，该液冷装置的下底面具有冷却液出口，冷却液采用水，因此该冷却装置也叫做水冷装置6，该水冷装置6还包括用于进水的进水管7，设置于水冷装置6的侧壁上，以向水冷装置内部供冷却水，冷却水再由冷却液出口向下流出形成环形冷却水幕10，冷却水幕10内部即为冷却区，用于冷却合金粉末中间体使其形成非晶合金粉末11。本发明在气雾化器下方增加一个环形水冷装置6，环形水冷装置6位于气流喷嘴3的外侧，该水冷装置6可以向下方流出或喷出冷却水，以保证由环形水幕围成的冷却区具有合适的温度，从而将经过该冷却区的合金小液滴冷却形成非晶粉末。合金熔液经过导液管4底部的喷出口喷出，当合金熔液被高压气体打击破碎成小金属液滴后，因气体冷却速度远远低于水的冷却速度，所以金属液滴在表面张力的作用下形成球形粉末颗粒，粉末颗粒在下落过程中经过雾化器下方环形水冷装置喷射出的冷却水幕10，球形颗粒被快速冷却得到非晶合金粉末11。
本发明的制备装置适合制备各种非晶合金粉末，特别适用于制备FeSiB系非晶合金粉末；优选地，按照质量百分比，所述非晶合金粉末的组分包括：Si：1-14％、B：7-15％、C：≤4％、Cu：≤3％、Nb：≤4％、P：≤2％，余量为Fe和不可避免的杂质；比如所述FeSiB系非晶合金粉末为AP01、AP02或AP03合金粉末；所述AP01合金粉末化学成分按质量百分比为：Cu：1％、Nb：3％、Si：13.5％、B：9％、Fe：余量以及不可避免的杂质；所述AP02合金化学成分按质量百分比为：Cu：1％、Nb：1％、Si：4％、B：9％、C：0.3％、Fe：余量以及不可避免的杂质；所述AP03合金化学成分按质量百分比为：Cu：1.2％、Si：2％、B：12％、P：2％、Fe：余量以及不可避免的杂质。
本发明还提供了球形非晶合金粉末的制备方法，包括如下步骤：
S1：在将金属原料放入真空中频感应炉中加热熔化，钢液温度根据材料不同而进行选择；一般是加热至1300～1600℃，优选在高于所述原料熔点 50～250℃、更优选150～200℃的条件下将所述原料熔化，真空度控制10Pa以下(比如9Pa、7Pa、6Pa、1Pa、0.1Pa)，得到所述合金熔液；
S2：在真空或惰性气氛下，采用惰性雾化气体对所述合金熔液进行雾化处理，得到合金粉末中间体；
优选地，所述雾化处理时，根据粒度要求选择合适雾化压力，雾化气体压力(即用于雾化的气体的喷出压力)为2～6Mpa(比如2.5Pa、3Pa、4Pa、5Pa、5.5Pa)；所述雾化处理时的真空度控制10Pa以下(比如9Pa、7Pa、6Pa、1Pa、0.1Pa)；所述惰性雾化气体为氮气或氩气。
S3：所述合金粉末中间体进入冷却区进行冷却，得到所述球形非晶合金粉末；优选所述冷却的速率为10 6K/s以上(比如2*10 6K/s、4*10 6K/s、6*10 6K/s、8*10 6K/s、9*10 6K/s、2*10 7K/s、4*10 7K/s、6*10 7K/s、8*10 7K/s、9*10 7K/s)；更优选所述冷却的速率为10 6-10 7K/s。
下面通过实施例来进一步说明本发明的制备方法，以下制备方法的实施例均采用了本发明的制备装置，其中，气流喷嘴3喷出气流的方向与竖向(即导液管的轴向)呈45°，导液管4的内腔从上到下由倒锥形过渡为圆筒状，倒锥形的锥角为10°，冷却液为水，液冷装置可以形成冷却水幕。
实施例1
本实施例制备AP01非晶粉末，其化学成分(按质量百分比计算)为：Cu：1％、Nb：3％、Si：13.5％、B：9％、Fe：余量。未提及的元素为不可避免的杂质。
制备方法如下：
(1)在真空度5Pa的环境气氛下将原料加热至1325℃下熔化，得到合金熔液；
(2)在真空度5Pa的环境气氛下采用氩气作为雾化气体进行雾化处理，得到破碎的且球化的合金粉末中间体，其中，雾化温度(即中间包中合金熔液的温度)为1320℃，雾化气体压力为2.2Mpa；
(3)合金粉末中间体向下进入冷却水幕形成的冷却区进行冷却，冷却速度为2*10 6K/s以上，最后收集非晶合金粉末。
通过扫描电子显微镜(SEM)对合金粉末进行观察，照片参见图5，从 图中可知，本发明方法制备的合金粉末球形度非常好，粒度D50:28μm。合金粉末的氧含量为319ppm。
通过X射线衍射分析得到XRD图谱，参见图6，从图中可知，所测粉末没有明显的衍射峰，为非晶合金粉末。
对比例1
该对比例1采用了现有气雾化设备进行制粉，原料以及前两步工艺均与实施例1相同，本对比例仅省略了步骤(3)的冷却步骤。该对比例得到的合金粉末，通过扫描电子显微镜(SEM)对其进行观察，参见图7，从图中可以看出，由于冷却速度降低，粉末的球形度变差。粒度D50为23μm，氧含量为613ppm。
通过X射线衍射分析得到XRD图谱，参见图8。从图中可知，该对比例制备的合金粉末已经出现衍射峰，粉末开始晶化。
实施例2：
本实施例制备AP02非晶合金粉末，其化学成分(按质量百分比计算)为：Cu：1％、Nb：1％、Si：4％、B：9％、C：0.3％、Fe：余量。未提及的元素为不可避免的杂质。
制备方法如下：
(1)在真空度8Pa的环境气氛下将原料加热至1425℃下熔化，得到合金熔液；
(2)在真空度8Pa的环境气氛下采用氩气作为雾化气体进行雾化处理，得到破碎的且球化的合金粉末中间体，其中，雾化温度(即中间包中合金熔液的温度)为1420℃，雾化气体压力为6Mpa；
(3)合金粉末中间体向下进入冷却水幕形成的冷却区进行冷却，冷却速度为2*10 6K/s以上，最后收集非晶合金粉末。
通过扫描电子显微镜(SEM)对合金粉末进行观察，照片参见图9，从图中可知，本发明方法制备的合金粉末球形度非常好，粒度D50:10μm。合金粉末的氧含量为503ppm。
通过X射线衍射分析得到XRD图谱，参见图10，从图中可知，所测粉 末没有明显的衍射峰，为非晶合金粉末。
对比例2
该对比例2采用了现有气雾化设备(即无液冷装置)进行制粉，原料以及前两步工艺均与实施例2相同，本对比例仅省略了步骤(3)的冷却步骤。该对比例得到的合金粉末，通过扫描电子显微镜(SEM)对其进行观察，参见图11，从图中可以看出，由于冷却速度降低，粉末中的不规则形状颗粒明显增多，球形度变差。粒度D50为11μm，氧含量为762ppm。
通过X射线衍射分析得到XRD图谱，参见图12，从图中可知，该对比例制备的合金粉末已经出现衍射峰，粉末开始晶化。
实施例3：
本实施例制备AP03非晶合金粉末，其化学成分(按质量百分比计算)为：Cu：1.2％、Si：2％、B：12％、P：2％、Fe：余量。未提及的元素为不可避免的杂质。
制备方法如下：
(1)在真空度3Pa的环境气氛下将原料加热至1385℃下熔化，得到合金熔液；
(2)在真空度3Pa的环境气氛下采用氩气作为雾化气体进行雾化处理，得到破碎的且球化的合金粉末中间体，其中，雾化温度(即中间包中合金熔液的温度)为1380℃，雾化气体压力为3.6Mpa；
(3)合金粉末中间体向下进入冷却水幕形成的冷却区进行冷却，冷却速度为2*10 6K/s以上，最后收集非晶合金粉末。
通过扫描电子显微镜(SEM)对合金粉末进行观察，参见图13，从图中可知，本发明方法制备的合金粉末球形度非常好，粒度D50:17μm。合金粉末的氧含量为361ppm。
通过X射线衍射分析得到XRD图谱，参见图14，从图中可知，所测粉末没有明显的衍射峰，为非晶合金粉末。
对比例3
该对比例3采用了现有气雾化设备进行制粉，原料以及前两步工艺均与实施例3相同，本对比例仅省略了步骤(3)的冷却步骤。该对比例得到的合金粉末，通过扫描电子显微镜(SEM)对其进行观察，参见图15，从图中可以看出，由于冷却速度降低，粉末中的不规则形状颗粒明显增多，球形度变差。粒度D50为18μm，氧含量为537ppm。
通过X射线衍射分析得到XRD图谱，参见图16，从图中可知，该对比例制备的合金粉末已经出现衍射峰，粉末开始晶化。
小结
实施例1-3所得粉末没有明显的衍射峰，为非晶合金粉末，而对比例1-3所得粉末有明显的衍射峰，粉末出现晶化，由此可见，本发明的雾化制粉装置可以获得粒度更均一、球形更规则、含氧量更小的非晶粉末。另外，本发明方法和装置可以获得相对尺寸较大的球形非晶粉末，可提高磁导率，特别适用于FeSiB系非晶合金粉末的制备。
由技术常识可知，本发明可以通过其它的不脱离其精神实质或必要特征的实施方案来实现。因此，上述公开的实施方案，就各方面而言，都只是举例说明，并不是仅有的。所有在本发明范围内或在等同于本发明的范围内的改变均被本发明包含。

Claims (10)

  1. 一种球形非晶合金粉末制备装置，所述制备装置包括：
    气雾化器，用于采用雾化气体将合金熔液破碎；
    液冷装置，位于所述气雾化器下方且设置于所述气雾化器的气流喷嘴外围，用于将所述气雾化器破碎后的合金粉末中间体冷却形成球形非晶合金粉末。
  2. 如权利要求1所述的制备装置，其特征在于，所述制备装置还包括导液管，连接装有所述合金熔液的中间包和所述气雾化器；
    优选，所述导液管上端与所述中间包连通；
    优选，所述导液管下端部座设于所述气雾化器的对应插口；
    优选，所述导液管的内腔从上到下呈倒锥形，锥角为0-15°；
    优选，所述导液管的内腔从上到下由倒锥形过渡为圆筒状，锥角为1-15°。
  3. 如权利要求1所述的制备装置，其特征在于，
    在所述气雾化器的侧壁上设置有用于向所述气雾化器中通入所述雾化气体的进气管；
    优选，在所述气雾化器下部围绕合金熔液出口设置有用于破碎所述合金熔液的气流喷嘴；
    优选，所述气流喷嘴呈环形设置；
    优选，所述气流喷嘴喷出气流的方向与竖向呈40-50°夹角。
  4. 如权利要求1所述的制备装置，其特征在于，
    所述液冷装置呈环形设置于所述气流喷嘴外围，用于形成冷却所述合金粉末中间体的环形冷却区；
    优选地，所述液冷装置为具有双层壁的筒形结构，且所述液冷装置下底面设置有冷却液出口，用于冷却液向下流出形成冷却液幕，所述冷却液幕形成冷却所述合金粉末中间体的环形冷却区，更优选地，所述冷却液为水；或者所述液冷装置为具有双层壁的筒形结构，所述双层壁之间的空间填充有冷 却液，筒形结构的中空区域是用于冷却所述合金粉末中间体的环形冷却区，更优选地，所述冷却液为液氮；
    优选地，所述液冷装置固定于所述气雾化器的下底面上；
    优选，所述液冷装置的侧壁上设置有用于向所述液冷装置注入冷却液的进液管。
  5. 如权利要求1所述的制备装置，其特征在于，
    所述非晶合金粉末为FeSiB系非晶合金粉末；优选地，按照质量百分比，所述非晶合金粉末的组分包括：Si：1-14％、B：7-15％、C：≤4％、Cu：≤3％、Nb：≤4％、P：≤2％，余量为Fe和不可避免的杂质；
    更优选地，所述FeSiB系非晶合金粉末为AP01、AP02或AP03合金粉末；
    所述AP01合金粉末化学成分按质量百分比为：Cu：1％、Nb：3％、Si：13.5％、B：9％、Fe：余量以及不可避免的杂质；
    所述AP02合金化学成分按质量百分比为：Cu：1％、Nb：1％、Si：4％、B：9％、C：0.3％、Fe：余量以及不可避免的杂质；
    所述AP03合金化学成分按质量百分比为：Cu：1.2％、Si：2％、B：12％、P：2％、Fe：余量以及不可避免的杂质。
  6. 一种球形非晶合金粉末制备方法，所述制备方法包括如下步骤：
    S1：将原料熔化，得到合金熔液；
    S2：在真空或惰性气氛下，采用惰性雾化气体对所述合金熔液进行雾化处理，得到合金粉末中间体；
    S3：所述合金粉末中间体进入冷却区进行冷却，得到所述球形非晶合金粉末。
  7. 如权利要求6所述的制备方法，其特征在于，
    在步骤S1中，在高于所述原料熔点50～250℃的条件下将所述原料熔化，得到所述合金熔液；
    优选，在步骤S1中，在高于所述原料的熔点150～200℃的条件下将所述 原料熔化，得到所述合金熔液。
  8. 如权利要求6所述的制备方法，其特征在于，
    在步骤S2中，所述雾化处理时，雾化气体压力为2～6Mpa；
    所述雾化处理时的真空度控制10Pa以下；
    优选，在步骤S2中，所述惰性雾化气体为氮气或氩气；
    优选，在步骤S3中，所述冷却的速率为10 6K/s以上；
    优选，所述冷却的速率为10 6-10 7K/s。
  9. 如权利要求6-8中任一项所述的制备方法，其特征在于，
    所述球形非晶合金粉末制备方法是使用权利要求1-5中任一项所述的球形非晶合金粉末制备装置进行的。
  10. 一种球形非晶合金粉末，所述球形非晶合金粉末是根据权利要求1-5中任一项所述的球形非晶合金粉末制备装置或权利要求6-8中任一项所述的球形非晶合金粉末制备方法制备得到的。
PCT/CN2020/140078 2020-05-27 2020-12-28 一种球形非晶合金粉末制备装置与方法 WO2021139553A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2021548216A JP7234392B2 (ja) 2020-05-27 2020-12-28 球形非晶質合金粉末調製装置および方法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010463311.7 2020-05-27
CN202010463311.7A CN111534765B (zh) 2020-05-27 2020-05-27 一种球形非晶合金粉末制备装置与方法

Publications (1)

Publication Number Publication Date
WO2021139553A1 true WO2021139553A1 (zh) 2021-07-15

Family

ID=71974722

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/140078 WO2021139553A1 (zh) 2020-05-27 2020-12-28 一种球形非晶合金粉末制备装置与方法

Country Status (3)

Country Link
JP (1) JP7234392B2 (zh)
CN (1) CN111534765B (zh)
WO (1) WO2021139553A1 (zh)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113652625A (zh) * 2021-08-17 2021-11-16 上海浦海求实电力新技术股份有限公司 用于钻石型配电网的电力排管内表面喷涂材料及其制备方法
CN113649581A (zh) * 2021-07-29 2021-11-16 南方科技大学 一种雾化系统及固体粉末制备方法
CN114589310A (zh) * 2022-03-11 2022-06-07 晶高优材(北京)科技有限公司 一种微米球形银粉制备方法
CN116043138A (zh) * 2023-01-03 2023-05-02 深圳市铂科新材料股份有限公司 一种铁基非晶软磁材料及其制备方法

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111534765B (zh) * 2020-05-27 2024-03-15 安泰（霸州）特种粉业有限公司 一种球形非晶合金粉末制备装置与方法
CN112170857B (zh) * 2020-09-30 2023-07-07 宁波中科毕普拉斯新材料科技有限公司 一种微细合金粉末的制备方法
CN112743094A (zh) * 2020-12-29 2021-05-04 南通金源智能技术有限公司 一种新型微细非晶磁粉的制备方法及装置
CN113369485A (zh) * 2021-06-10 2021-09-10 盘星新型合金材料(常州)有限公司 中试雾化炉、Fe基非晶合金粉末及其制备方法

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010007100A (ja) * 2008-06-24 2010-01-14 Hitachi Metals Ltd 合金粉末およびその製造方法
CN104084596A (zh) * 2014-07-15 2014-10-08 中国科学院宁波材料技术与工程研究所 非晶态粉末的制备方法及装置
CN104376950A (zh) * 2014-12-12 2015-02-25 安泰科技股份有限公司 一种铁基恒导磁纳米晶磁芯及其制备方法
KR20170088317A (ko) * 2017-07-18 2017-08-01 공주대학교 산학협력단 비정질 합금분말 제조 장치, 그 제조 방법 및 비정질 합금분말
CN107578877A (zh) * 2017-06-29 2018-01-12 安泰科技股份有限公司 一种磁导率μ=90的铁基纳米晶磁粉芯及其制备方法
CN107900364A (zh) * 2017-11-07 2018-04-13 常州大学 一种超声雾化再冷却法制备金属非晶粉末的装置
CN111534765A (zh) * 2020-05-27 2020-08-14 安泰（霸州）特种粉业有限公司 一种球形非晶合金粉末制备装置与方法
CN111590083A (zh) * 2020-05-27 2020-08-28 安泰（霸州）特种粉业有限公司 一种球形纳米晶合金粉末制备方法

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3932573B2 (ja) * 1996-08-30 2007-06-20 セイコーエプソン株式会社 金属粉末の製造装置
JP2001131613A (ja) * 1999-11-11 2001-05-15 Daido Steel Co Ltd 噴霧ノズル装置
CN105397100B (zh) * 2014-08-25 2018-01-12 中国科学院宁波材料技术与工程研究所 一种微细金属粉末的制备方法及实现该方法的设备
KR101646986B1 (ko) * 2014-11-21 2016-08-09 공주대학교 산학협력단 비정질 합금 분말 제조 장치 및 그 방법
CN106694895A (zh) * 2017-03-13 2017-05-24 湖南旭博冶金科技有限公司 一种水气联合雾化制粉器
JP6904034B2 (ja) 2017-04-17 2021-07-14 セイコーエプソン株式会社 軟磁性粉末、圧粉磁心、磁性素子および電子機器
JP6323603B1 (ja) * 2017-08-08 2018-05-16 Tdk株式会社 金属粉末製造装置と金属粉末の製造方法
CN108172359A (zh) * 2017-11-28 2018-06-15 嘉兴长维新材料科技有限公司 球形铁基非晶合金粉末及其制备方法和在制备非晶磁粉芯中的应用
CN212857768U (zh) * 2020-05-27 2021-04-02 安泰（霸州）特种粉业有限公司 一种合金粉末制备装置

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010007100A (ja) * 2008-06-24 2010-01-14 Hitachi Metals Ltd 合金粉末およびその製造方法
CN104084596A (zh) * 2014-07-15 2014-10-08 中国科学院宁波材料技术与工程研究所 非晶态粉末的制备方法及装置
CN104376950A (zh) * 2014-12-12 2015-02-25 安泰科技股份有限公司 一种铁基恒导磁纳米晶磁芯及其制备方法
CN107578877A (zh) * 2017-06-29 2018-01-12 安泰科技股份有限公司 一种磁导率μ=90的铁基纳米晶磁粉芯及其制备方法
KR20170088317A (ko) * 2017-07-18 2017-08-01 공주대학교 산학협력단 비정질 합금분말 제조 장치, 그 제조 방법 및 비정질 합금분말
CN107900364A (zh) * 2017-11-07 2018-04-13 常州大学 一种超声雾化再冷却法制备金属非晶粉末的装置
CN111534765A (zh) * 2020-05-27 2020-08-14 安泰（霸州）特种粉业有限公司 一种球形非晶合金粉末制备装置与方法
CN111590083A (zh) * 2020-05-27 2020-08-28 安泰（霸州）特种粉业有限公司 一种球形纳米晶合金粉末制备方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ISAMU OTSUKA ET AL.: "Magnetic Properties Of Fe-Based Amorphous Powders With High-Saturation Induction Produced By Spinning Water Atomization Process (SWAP)", IEEE TRANSACTIONS ON MAGNETICS, vol. 44, no. 11, 30 November 2008 (2008-11-30), XP011240172, ISSN: 0018-9464, DOI: 10.1109/TMAG.2008.2002249 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113649581A (zh) * 2021-07-29 2021-11-16 南方科技大学 一种雾化系统及固体粉末制备方法
CN113652625A (zh) * 2021-08-17 2021-11-16 上海浦海求实电力新技术股份有限公司 用于钻石型配电网的电力排管内表面喷涂材料及其制备方法
CN114589310A (zh) * 2022-03-11 2022-06-07 晶高优材(北京)科技有限公司 一种微米球形银粉制备方法
CN116043138A (zh) * 2023-01-03 2023-05-02 深圳市铂科新材料股份有限公司 一种铁基非晶软磁材料及其制备方法

Also Published As

Publication number Publication date
JP7234392B2 (ja) 2023-03-07
CN111534765B (zh) 2024-03-15
CN111534765A (zh) 2020-08-14
JP2022520489A (ja) 2022-03-30

Similar Documents

Publication Publication Date Title
WO2021139553A1 (zh) 一种球形非晶合金粉末制备装置与方法
CN111590083B (zh) 一种球形纳米晶合金粉末制备方法
CN104858441B (zh) 一种微细片状金属软磁合金粉末的制备方法
CN107900367B (zh) 一种3d打印用钛及钛合金粉末的新型雾化器
CN105397100B (zh) 一种微细金属粉末的制备方法及实现该方法的设备
CN107900366B (zh) 气雾化连续制备3d打印用钛或钛合金粉末的装置及方法
CN105945294A (zh) 一种铁硅铬软磁粉末、其制备方法及其应用
CN109967755B (zh) 一种球形微细金属粉体生产系统及其方法
CN108247074A (zh) 一种用于制备低成本高纯净度球形金属粉体的装置及方法
CN107716934A (zh) 一种用于3D打印技术的Inconel718合金粉末的制备方法
CN102476184A (zh) 一种铜粉及其制作方法、制作装置和散热件
CN212857768U (zh) 一种合金粉末制备装置
KR101782095B1 (ko) 비정질 합금분말 제조 장치, 그 제조 방법 및 비정질 합금분말
CN109877343A (zh) 一种适用于3d打印的高品质球形钛粉的制备方法
KR20170038274A (ko) 지르코늄 분말 또는 지르코늄합금 분말의 제조방법 및 그에 따른 지르코늄 분말 또는 지르코늄합금 분말
JP2017031462A (ja) 水アトマイズ金属粉末の製造方法
CN113458401A (zh) 一种铁镍钼软磁粉末的制备方法
KR100671250B1 (ko) 금속 분말의 제조 방법 및 제조 장치
JP2018104787A (ja) アトマイズ金属粉末の製造方法及びアトマイズ金属粉末の製造装置
KR102296910B1 (ko) 냉각효율을 높인 비정질 자성분말 제조장치 및 이를 이용한 비정질 자성분말 제조방법
KR100819534B1 (ko) 고압 수 분사 장치 및 이를 이용한 초 미립의 금속 분말의제조 방법
KR20000049741A (ko) 고압수분사법에 의한 비정질 금속분말의 제조방법.
CN103273054B (zh) 一种铜粉及应用该铜粉的散热件
CN111496264A (zh) 一种合金粉末制备装置与方法
CN113369485A (zh) 中试雾化炉、Fe基非晶合金粉末及其制备方法

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2021548216

Country of ref document: JP

Kind code of ref document: A

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20911358

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20911358

Country of ref document: EP

Kind code of ref document: A1