阅读说明：本技术 一种粉末材料压片成型的模具及方法 (Die and method for tabletting and forming of powder material ) 是由 杨益航 陈文练 赵国璋 张厚安 古思勇 于 2021-09-08 设计创作，主要内容包括：本发明提供了一种粉末材料压片成型的模具及方法,包括上模以及与上模相对设置的凹模,所述上模与凹模之间设有一传递力的金属薄片,所述金属薄片下方设置有金属或陶瓷粉末且所述粉末材料设置于所述凹模内,所述上模内部凹陷形成有燃烧腔,且所述上模位于燃烧腔内部设置有用于放置燃爆发生物的容置件；上模的容置件内放入燃爆发生物,上模外的压电陶瓷导线穿过上模壁连接所述燃爆发生物；上模与凹模装配后由模架锁紧；在整套模具外按压压电陶瓷,其释放电压经导线传导至上模腔内,产生的电火花引燃所述燃爆发生物；使得金属薄片实现瞬间的冲击及高温并作用于所述粉末材料,使其产生极高的压缩应变速率并促进其烧结致密后成型。(The invention provides a die and a method for forming a powder material tablet, which comprises an upper die and a female die arranged opposite to the upper die, wherein a metal sheet for transmitting force is arranged between the upper die and the female die, metal or ceramic powder is arranged below the metal sheet, the powder material is arranged in the female die, a combustion cavity is formed in the upper die in a concave manner, and a containing piece for containing combustion organisms is arranged in the combustion cavity of the upper die; explosive organisms are put into the accommodating part of the upper die, and a piezoelectric ceramic wire outside the upper die penetrates through the wall of the upper die and is connected with the explosive organisms; the upper die and the female die are locked by the die frame after being assembled; pressing piezoelectric ceramics outside the whole set of die, and conducting the release voltage of the piezoelectric ceramics into the upper die cavity through a lead, so that the generated electric sparks ignite the explosive organisms; the metal sheet can realize instant impact and high temperature and act on the powder material, so that the powder material generates extremely high compression strain rate and promotes the sintering and densification of the powder material and then is molded.)

1. A die for forming a powder material tablet is characterized by comprising an upper die and a female die arranged opposite to the upper die, wherein a metal sheet for transmitting force is arranged between the upper die and the female die, metal or ceramic powder is arranged below the metal sheet, the powder material is arranged in the female die, a combustion cavity is formed in the upper die in a concave manner, and a containing piece for containing combustion organisms is arranged in the combustion cavity of the upper die; explosive organisms are put into the accommodating part of the upper die, and a piezoelectric ceramic wire outside the upper die penetrates through the wall of the upper die and is connected with the explosive organisms; the upper die and the female die are locked by the die frame after being assembled; pressing piezoelectric ceramics outside the whole set of die, and conducting the release voltage of the piezoelectric ceramics into the upper die cavity through a lead, so that the generated electric sparks ignite the explosive organisms; the metal sheet can realize instant impact and high temperature and act on the powder material, so that the powder material generates extremely high compression strain rate and promotes the sintering and densification of the powder material and then is molded.

2. A die for tablet forming of powdered material according to claim 1, wherein the metal powder is a powder of one or more of tungsten, molybdenum, tantalum, niobium, magnesium, titanium and alloys thereof.

3. A die for forming a tablet of a powdered material according to claim 1 wherein said ceramic powder is a powder formed from one or more of alumina, zirconia, silica and mixtures thereof.

4. A die for tablet forming of powdered material according to claim 1, wherein the metal flakes are flakes formed from one of copper, iron, aluminum, titanium and alloys thereof.

5. A die for tablet forming of powdered material according to claim 1, wherein the metal foil is a stainless steel foil.

6. A die for tablet forming of powdered material according to claim 1 wherein the combustion explosive organisms are a mixture of one or more of gasoline, diesel fuel, ammonium nitrate, nitroglycerin and trinitrotoluene.

7. A die for forming a tablet of powdered material according to any one of claims 1-6, characterised in that the female die is arranged on a die base, and that a spacer is arranged between the powdered material and the die base.

8. A die for forming a tablet of powdered material according to claim 4, wherein the upper die, the female die and the die base are disposed in a partition, and the partition comprises a pressure bracket, a handle and a buckle, and the pressure bracket supports the handle and the buckle.

9. A method for forming a tablet of powdered material, characterized in that it uses a mould according to claim 7 and comprises the following steps: (1) adjusting the tabletting mold to enable the whole set of mold to be locked after being closed; (2) placing a powder material to be molded on a cushion block and filling the concave die cavity, and placing a metal sheet on the powder material; (3) placing the blasting substance in the upper die accommodating piece; (4) closing and pressing the upper die and the female die; (5) electric sparks are generated by the piezoelectric ceramics outside the upper die to ignite explosive organisms; (6) the explosive organisms explode in the closed space to release high temperature and high pressure, and act on the powder material through the metal sheet, so that the effect of tabletting and forming of the high temperature and high pressure is achieved.

10. A method of tablet forming of a powdered material according to claim 9, wherein the powder is loose in the die and has an aspect ratio in the range of: 1: 2-1: 20, and the more preferable range of the height-diameter ratio is as follows: 1:5 to 1: 10.

Technical Field

The invention relates to the technical field of powder material processing, in particular to a high-strain-rate high-temperature high-pressure tabletting and forming method for metal and ceramic powder.

Background

In the tablet forming of metal powder, a tablet die is an indispensable tool. At present, the traditional powder tabletting mould mainly comprises four parts, namely a forming head, a mould cylinder, a mould core and a base, and is simple and convenient to operate. However, the conventional powder material tablet forming has a slow compression speed, and is difficult to realize simultaneous loading of high temperature and high pressure. The explosion characteristics of gunpowder and the like are utilized to be applied to the tabletting and forming of metal powder, and the explosion tabletting and forming method which has high forming efficiency and easy operation is developed, can promote the direct sintering of the metal powder, and can keep the fine tissue form of a tabletting block at high strain rate. But also has important significance for the tabletting and forming of powder of refractory metals and the like. In the prior art, for example, chinese patent CN109702071B is a burning explosion forming mold and a forming method thereof, and the utility model CN210253810U is a continuous processing device for a metal plate difficult to deform, both of them propose a device which can make burning explosion products reach burning point through heat transfer to generate violent heat release, so as to make the metal plate to be formed be stretched and deformed and be attached to the forming cavity of the lower mold for forming. The forming mode is not easy to control the time point of the explosion, and the danger of explosion caused by the mode locking is existed. These prior art techniques are all included in the solutions for reforming a metal sheet to be formed, i.e. the size and shape of the initial object to be formed are limited and not adapted to the forming of the initial object in powder material.

Disclosure of Invention

Based on the problems in the background art, the invention provides a die and a method for tabletting and forming a powder material.

The invention adopts the following scheme: a die for forming a powder material tablet comprises an upper die and a female die arranged opposite to the upper die, wherein a metal sheet for transmitting force is arranged between the upper die and the female die, the powder material is arranged below the metal sheet and is arranged in the female die, a combustion cavity is formed in the upper die in a concave manner, and a containing piece for containing combustion organisms is arranged in the combustion cavity of the upper die; explosive organisms are put into the accommodating part of the upper die, and a piezoelectric ceramic wire outside the upper die penetrates through the wall of the upper die and is connected with the explosive organisms; the upper die and the female die are locked by the die frame after being assembled; pressing piezoelectric ceramics outside the whole set of die, and conducting the release voltage of the piezoelectric ceramics into the upper die cavity through a lead, so that the generated electric sparks ignite the explosive organisms; the powder material is subjected to instantaneous impact and high temperature action on the metal sheet, so that the metal sheet generates extremely high compressive strain rate and promotes the sintering and densification of the metal sheet for forming.

Preferably, the metal powder is a powder formed from one or more of tungsten, molybdenum, tantalum, niobium, magnesium, titanium, and alloys thereof.

Preferably, the ceramic powder is a powder formed by one or more of alumina, zirconia, silica and mixed powder thereof.

Preferably, the metal foil is a foil formed of one of copper, iron, aluminum, titanium and an alloy thereof.

Preferably, the metal sheet is a stainless steel sheet.

Preferably, the combustion explosive organisms are a mixture of one or more of gasoline, diesel, ammonium nitrate, nitroglycerin and trinitrotoluene.

Preferably, the female die is arranged on a die base, and a cushion block is arranged between the powder material and the die base.

Preferably, the upper die, the female die and the die base are all arranged in a partition, the partition comprises a pressure support, a handle and a buckle, and the pressure support supports the handle and the buckle.

A method of tablet forming of a powdered material using a mould as described above and comprising the steps of: (1) adjusting the tabletting mold to enable the whole set of mold to be locked after being closed; (2) placing a powder material to be molded on a cushion block and filling the concave die cavity, and placing a metal sheet on the powder material; (3) placing the blasting substance in the upper die accommodating piece; (4) closing and pressing the upper die and the female die; (5) electric sparks are generated by the piezoelectric ceramics outside the upper die to ignite explosive organisms; (6) the explosive organisms explode in the closed space to release high temperature and high pressure, and act on the powder material through the metal sheet, so that the effect of tabletting and forming of the high temperature and high pressure is achieved.

Preferably, the ranges of high temperature and high pressure are: the high temperature range is 200 ℃ and 2000 ℃, and the high pressure range is 50-1000 MPa.

By adopting the technical scheme, the invention can obtain the following technical effects: the invention utilizes the burning and exploding characteristics of gunpowder and the like to apply the powder material to the tabletting and forming of the powder material, develops a high-efficiency and easy-operation burning and exploding tabletting and forming method, and realizes the tabletting and forming of the powder material by pressing the piezoelectric ceramics, transmitting the release voltage of the piezoelectric ceramics to the upper die cavity through a lead and igniting the burning and exploding product by the generated electric spark. Therefore, on one hand, the direct sintering of the powder material can be promoted by the combustion and explosion heat energy, the fine tissue form of the tabletting block can be kept at a high strain rate, on the other hand, the detonation can be carried out in a conductive mode, and compared with the prior art, the combustion and explosion process is easier to control, and the energy utilization rate is higher. And the targeted object is a powder material, and the method has important significance for fine-grained and homogeneous microstructures formed by tabletting powder of refractory metals and the like.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic view of a die for forming a tablet of powder material according to the present invention.

In the figure: 1-cushion block; 2-flakes; 3, molding the die; 4-a powder material; 5-a female die; 6-slipknot; 7-a handle; 8-a pressure support; 9-mould base.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the equipment or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Examples

The following are only preferred embodiments of the present invention, and the scope of the present invention is not limited to the following examples, and all technical solutions belonging to the idea of the present invention belong to the scope of the present invention.

Referring to the attached figure 1 of the specification, a die for forming a powder material tablet comprises an upper die 3 and a female die 5 arranged opposite to the upper die, wherein a metal sheet 2 for transmitting force is arranged between the upper die 3 and the female die 5, a powder material 4 is arranged below the metal sheet 2 and is arranged in the female die 5, a combustion cavity is formed in the upper die 3 in a concave manner, and an accommodating piece for accommodating combustion explosive organisms is arranged in the combustion cavity of the upper die; explosive organisms are placed in the accommodating part of the upper die, a piezoelectric ceramic wire outside the upper die penetrates through the wall of the upper die to be connected with the explosive organisms, the female die 5 is arranged on a die base 9, and a cushion block 1 is arranged between the powder material 4 and the die base 9; go up mould 3, die 5 and mould base 9 and all set up in the isolator, the isolator is including pressure bracket 8, handle 7 and slipknot 6, pressure bracket 8 supports handle and slipknot.

The upper die 3 and the female die 5 are locked by a die frame after being assembled; pressing piezoelectric ceramics outside the whole set of die, and conducting the release voltage of the piezoelectric ceramics into the cavity of the upper die 3 through a lead, so that the generated electric sparks ignite the explosive organisms; the metal sheet 2 is enabled to realize instant impact and act on the powder material 4, so that the powder material 4 generates extremely high compression strain rate, and the compact sintering of the powder material 4 is promoted through the metal sheet 2 due to the high burning and blasting temperature. The powder material 4 comprises a powder of one or more of the metals tungsten, molybdenum, tantalum, niobium, magnesium, titanium and alloys thereof, the powder material 4 further comprising a ceramic. The metal sheet 2 is a sheet formed by one of copper, iron, aluminum, titanium and alloy thereof or a stainless steel sheet. The combustion explosive organisms are a mixture formed by one or more of gasoline, diesel oil, ammonium nitrate, nitroglycerin and trinitrotoluene.

A method of tablet forming of a powdered material using a mould as described above and comprising the steps of: (1) adjusting the tabletting mold to enable the whole set of mold to be locked after being closed; (2) placing a powder material 4 to be molded on a cushion block 1 and filling a concave die cavity, and placing a metal sheet 2 on the powder material 4; (3) placing the blasting substance in the upper die accommodating piece; (4) closing and pressing the upper die 3 and the female die 5; (5) electric sparks are generated by piezoelectric ceramics outside the upper die 3 to ignite explosive organisms; (6) the explosive organisms explode in the closed space to release high temperature and high pressure, and act on the powder material through the metal sheet, so that the effect of tabletting and forming of the high temperature and high pressure is achieved. The high temperature range is 200 ℃ and 2000 ℃, and the high pressure range is 50-1000 MPa.

The specific embodiment is as follows: in the first embodiment, the inner diameter of the female die 5 is 50 mm, the outer diameter of the female die is 100 mm, and the height of the female die is 60 mm; the diameter of the cushion block is 50 mm, and the height of the cushion block is 20 mm; the inner diameter of the combustion cavity in the upper die 3 is 50 mm, and the volume of the cavity is 100 ML. Firstly, placing a female die 5 in the center of a die base 9, and placing a cushion block 1 into the female die 5; filling pure tungsten powder into the female die 5 until the pure tungsten powder is flush with the steps of the female die; placing a 304 stainless steel wafer with the thickness of 0.2 mm and the diameter of 70 mm on the step of the female die; nitroglycerin with the mass of 0.2g is placed in the accommodating part of the upper die 3, and a piezoelectric ceramic wire outside the upper die 3 penetrates through the wall of the upper die and is connected with the nitroglycerin; the upper die 3 and the female die 5 are locked by a die frame after being assembled; the piezoelectric ceramic is pressed outside the whole set of die, the release voltage of the piezoelectric ceramic is conducted into the upper die cavity through the conducting wire, and the generated electric spark ignites the nitroglycerin to generate 1200J energy. The energy of instantaneous burning explosion of nitroglycerin is converted into high temperature and internal pressure, the stainless steel sheet realizes instantaneous stamping and drawing and acts on the tungsten powder to generate extremely high compressive strain rate, and the high temperature also promotes the sintering and densification of the tungsten powder. And after the forming is finished, unlocking the die, putting the push rod into the concave die, and putting the push rod into the jack to push out the formed tungsten block. The forming efficiency is high, the cooperation of a special tabletting and forming machine is not needed, and the high-density tabletting and forming of metal powder, especially the forming of refractory metal powder, is facilitated.

In the second embodiment, the inner diameter of the female die 5 is 50 mm, the outer diameter of the female die is 100 mm, and the height of the female die is 60 mm; the diameter of the cushion block is 50 mm, and the height of the cushion block is 20 mm; the inner diameter of the combustion cavity in the upper die 3 is 50 mm, and the volume of the cavity is 100 ML. Firstly, placing a female die 5 in the center of a die base 9, and placing a cushion block 1 into the female die 5; loading the molybdenum-copper mixed powder into a female die 5 until the molybdenum-copper mixed powder is flush with the steps of the female die; placing a pure copper wafer with the thickness of 0.2 mm and the diameter of 70 mm on the step of the female die; gasoline with the mass of 0.02g is put into the accommodating part of the upper die, and a piezoelectric ceramic wire outside the upper die 3 penetrates through the wall of the upper die to be connected with the gasoline; the upper die 3 and the female die 5 are locked by a die frame after being assembled; the piezoelectric ceramic is pressed outside the whole set of die, the release voltage of the piezoelectric ceramic is conducted into the upper die cavity through a lead, and the generated electric spark ignites gasoline to generate 920J energy. The energy of the gasoline instantaneous explosion is converted into high temperature and internal pressure, the copper sheet realizes instantaneous stamping and drawing and acts on the molybdenum-copper mixed powder to generate extremely high compression strain rate, and the high temperature also promotes the molybdenum-copper powder to be sintered and compact. And after the forming is finished, unlocking the mold, putting the push rod into the concave mold, and putting the push rod into the jack to eject the formed molybdenum-copper block. The forming efficiency is high, the cooperation of a special tabletting and forming machine is not needed, and the high-density tabletting and forming of metal alloy powder, especially the forming of refractory metal powder, is facilitated.

In the third embodiment, the inner diameter of the female die 5 is 50 mm, the outer diameter of the female die is 100 mm, and the height of the female die is 50 mm; the diameter of the cushion block is 50 mm, and the height of the cushion block is 20 mm; the inner diameter of the combustion cavity in the upper die 3 is 50 mm, and the volume of the cavity is 100 ML. Firstly, placing a female die 5 in the center of a die base 9, and placing a cushion block 1 into the female die 5; putting alumina ceramic powder with the granularity range of 10-20 mu m into the female die 5 until the alumina ceramic powder is flush with the steps of the female die; placing a pure copper wafer with the thickness of 0.2 mm and the diameter of 70 mm on the step of the female die; diesel oil with the mass of 0.05g is put into the accommodating piece of the upper die, and a piezoelectric ceramic wire outside the upper die 3 penetrates through the wall of the upper die to be connected with the diesel oil; the upper die 3 and the female die 5 are locked by a die frame after being assembled; the piezoelectric ceramic is pressed outside the whole set of die, the release voltage of the piezoelectric ceramic is conducted into the upper die cavity through the lead, and the generated electric spark ignites diesel oil to generate 2000J energy. The energy of instantaneous burning explosion of diesel oil is converted into high temperature and internal pressure, the copper sheet realizes instantaneous stamping and drawing and acts on ceramic powder to generate extremely high compressive strain rate, and the high temperature also promotes the sintering densification of the alumina ceramic powder. And after the forming is finished, unlocking the mold, putting the push rod into the concave mold, and putting the push rod into the jack to eject the formed ceramic block. The forming efficiency is high, the cooperation of a special tabletting forming machine is not needed, and the high-density tabletting forming of the ceramic powder is facilitated.