TWI223668B - Method for producing open-pore porous aluminum material - Google Patents

Abstract

A method for producing an open-pore porous aluminum material is used to produce an open-pore porous aluminum material with a high porosity, and comprises stacking ceramic globular particles to a desired shape, infusing a molten aluminum metal into the stacked bed, and using water to flush the composite to remove ceramic particles and obtain an open-pore porous aluminum material with interconnected pores, in which the ceramic globular particles are moldable and capable of forming an extremely tight stacking, thereby obtaining an open-pore porous material with a high porosity.

Description

V. Description of the invention (1) The present invention relates to a continuous recitation " refers to the main method of making porous aluminum, a porous aluminum material, and a special structure. The reason is that the pores are connected to each other and the shape of the porous metal is based on its pores. The first type is closed-cell foamed metal, and the connectivity of the coating can be divided into two categories. The pores of the porous foamed metal are ▲-the type is connectivity. Foamed metal. The main uses are heat insulation, sound insulation, resistance, and no interconnection with each other, and its main holes are connected with each other, its main impact, etc .; and the connected foamed metal & The main applications are heat exchange, electrode materials, and porous metal materials are lightweight and widely used. For example: air-permeable porous gold that can absorb energy, its applications are very much, battery electrode materials, liquid = filter, muffler, heat exchanger. Purified oxygen processor, self-lubricating :, liquid flow regulator, water-only aircraft, bearing, radiating plate anti-shock material in space ship body, / ship absorber, anti-shock material, impact. Noise traps, heaters, and building materials for foamable porous metals. . Impact energy absorbers, flame parts, automotive catalyst converters, or two, as the core of light-weight aerospace structure 'aircraft wing panels: heat exchangers, power supplies, radiators, shock absorbers, and vibration reduction materials Electronic Zhuang: How much is the connectivity of low temperature heat exchangers, air transportation equipment shielding materials, heat transfer materials, 2 small radiators, and aircraft waste heat shields?丨 i M insulation materials, noise protection, etc. 1 · The production method of particle stacking is divided into the following two categories: inside the container, and t packed bed between the particles, the particles are stacked in a container to remove the particles, two = there are voids), the molten aluminum is injected, Then the structure of the porous metal obtained at this time will be the same as that of page 5

2 Use PU-type foam as a mold, cover the foam mold with a financial material, such as ceramic powder 'stone lean', etc. to replicate its shape, and finally inject molten aluminum to obtain porous metal. The shape and structure of the porous metal is comparable to the polymer foam used. U.S. Patent No. 4 5 560 0 96 is based on the principle of die-casting method. The molten molten metal is pressed into a preform of inorganic salt particles prepared in advance, and the preform in the finished product is cooled and ejected after cooling. Remove to make connected porous metal. The inorganic salt particles used include: sodium nitrite (0.4-0.6 mm), sodium gasification (10-5000 // m), barium chloride (10-5000 # m), which emphasizes the accumulation Need to be heated beforehand. According to Banhart & Baumeister in Mater · Res. Soc ·,

Symp · proc · Issue 521, pp. I21-132 (1998), points out that the accumulation of other particles that have been, and are also included: eXpan (jed clay), hollow glass (hollow glass) sphere) etc. In the above-mentioned method using inorganic particles similar to the present invention, the disadvantages are: the shape of the particles is mostly irregular, taking salt particles as an example, because it is cheap and easy to dissolve and remove with water, it has the most competition However, because the salt particles are irregularly shaped particles and the hardness of the particles is high, it is not easy to obtain a very densely packed bed when forming a packed bed. For the reason, the final product porosity will not be too high.

Ma et al. In "Cellular structure controllable aluminum foams produced by high pressure infiltration process",

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Scripta Mett ·, No. 41, pp. 78 5-7 89 (1 9 9 9), pointed out the use of polystyrene (PS) spherical particles, adding resin as a binder, and then hardening to obtain a preform, and then using high pressure equipment, Aluminum is quickly pressed into the preform, and after heating, the polystyrene and resin are burned off to obtain a porous metal. The maximum porosity of the porous product obtained by this method is 85.8%. As mentioned above, when using particles like polystyrene, it is inevitable that high-temperature burning is required, and in the burning process, harmful gases or odorous gases are easily generated, causing environmental problems. In addition, high-pressure equipment is required to provide fast pressing of molten aluminum into the packed bed without affecting the accumulated polymer particles, thereby increasing the overall cost. ...

Yamada et al. In "Processing of an-open cellular AZ91 magnesium alloy with a low density 〇f 〇g / cm3", J · Mater · Sci · Let ·, No. 18, pp. 1477-1480 (1 9 9 9) 'Indicate the use of PU foam as a mold, then fill with gypsum to make a negative mold, and finally fill it with aluminum-magnesium alloy Finished product. U.S. Patent No. 3,946,039 mentions the use of particles of alkaline earth metal oxides, or salts, to replicate foam models. In addition, U.S. Patent No. 5,042,560 has emphasized the use of silicone-containing resins to thicken the fibers of the original foam to make the porous metal more coarse.

Banhar t & Baume iser et al. In "Production methods for metallic foams",

Mater · Res · Soc ·, Symp · Proc. No. 521, pp. 121-132

Page 7 1223668 V. Description of the invention (4) (1 9 9 8), mentioning that aluminum can be melted first, and then using a foaming agent, for example: titanium hydride (T i H2) for foaming, can be obtained after cooling Porous aluminum. However, this method yields closed-cell materials. U.S. Patent No. 4,283,465 mentions a method for sintering using metal powder, which is characterized by using a low melting point-containing aluminum alloy as a sintering aid. However, the porosity of the finished product is only between 3 3-50%. An object of the present invention is to provide a method for manufacturing a connected porous aluminum material, which is an improved method of a particle-stacked bed type, which is to form a high-density stacked bed with plastic ceramic particles at room temperature, thereby obtaining high porosity. Connected porous aluminum. The ceramic granules are made and made of cheap raw materials, and they are easy to remove after infusion of the molten inscription, so they have certain advantages in the manufacturing process. Compared with the inorganic particles and plastic examples, the particles used in the present invention are composed of heat-resistant ceramic powder, so they are not afraid of the high temperature of molten aluminum; and the spherical shape of the ceramic spherical particles is nearly spherical, and it is easy to compact. If a small amount of polymer additives such as polyvinyl alcohol (PVA, polyvinyl alcohol), sodium salt of carboxyme thyme cellulose (CMC-Na) are added to the particles to give the particles a little softness Under the proper molding pressure, it can be deformed to get a tighter packing, that is, the porosity of the finished product can be higher than the porosity of the product using salt particles. Finally, after the injection of molten aluminum is completed, these ceramic particles can be easily removed by rinsing with cold water. In order to allow your reviewers to further understand the technology, means and effects adopted by the present invention to achieve the intended purpose, a better and feasible implementation is exemplified.

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0 is 隹. The oxide powder is a-alumina particles with a particle size of 50111111, which

1223668 V. Description of invention (6) The preferred weight ratio is between 1 0 0: 0. 5 to 1 0 0: 2. 0, and 1 0 0: 1 · 0 is better. To produce the gap energy with hole energy, you need to build only the pile energy. The technology used to build the compaction reactor is to make the dense particles. After compaction, the bed is accumulated to the sub-piled to form a medium shape. It's tight. The medium-pressure Is has its pores and grains of poly-ceramics, and its color is clear. The hair product is said to be more abundant in high scores. For example, if the hole is from the hole to the top, it can be used easily. The porcelain under the ball is made of pottery and the hole is made of IX C a N salt. Food 0 uses quality to make the first precedent example of the nature of the system t ο chemical transformation I structure one or two Js. The V color 0 ° in the special 74 to Cheng Mingwen overheated aluminum cast out of the furnace to show that the temperature is not significantly higher, it is easy to avoid tolerance, and the grain can be used as a salt, such as coarsely divided. The actual salt will be screened according to the clock, and then the coarse salt particles after heat treatment will be screened by the 1.5 mm, 3 mm, and 5 mm divisions, and finally placed in an oven at 100 ° C to avoid moisture. Then enter the coarse salt particles. The experimental steps of aluminum casting are: firstly deposit coarse salt particles 2 on the bottom of mold 1 as a preform, and place an appropriate amount of aluminum block 3 on the preform, and then heat the mold in a high temperature furnace to 740 ° C. For 1.5 hours, after the aluminum block 3 is filled and melted, use the die 4 to press the molten molten aluminum into the preform. As shown in the first picture, after the cooling, the die 4 is removed and the shape of the body is roughened with water. The salt particles are washed away to obtain a connected porous metal aluminum. Fine salt particles can be placed on the bottom of the mold to prevent molten aluminum from coming out of the mold

Page 10 1223668 V. Description of the invention (7) Outflow. Due to the sharp angle structure of the coarse salt particles and the hardness of the particles themselves, it is difficult to obtain a very close packing. In other words, the preform obtained from the salt particles has a large pore. In contrast, when the molten aluminum is cast, the finished product The porosity is relatively low and usually can only be maintained at 50 ~ 60%. If the coarse salt particles are rolled in saturated saline for 3 hours, the effects of irregular shapes and sharp corners of the coarse salt particles can be slightly reduced, and the porosity of the finished product can be increased to 60 to 70%. However, the air permeability of this finished product is still not ideal because the porosity is not high enough [Example 1] The following steps were taken to make the connected porous aluminum: (1) Al2O3 powder, saponite, and betrayal曱 Base fiber sodium salt (CMC — Na) is mixed with 100: 1 ·· 2 (weight ratio) to form a powder portion; (2) Water and polyvinyl alcohol (PVA) are mixed with 10: 1 (weight ratio) to Form the solution part; (3) Mix the powder part and the solution part with 2: 1 ~ 3: 2 (weight ratio) to form the ceramic ball raw material; (4) The ceramic ball raw material is formed into a ceramic ball through a rolling granulation process, and the ceramic The diameter of the ball can be 3 ~ 10mm; (5) After the ceramic ball is poured into the mold, it is appropriately compressed to increase the bulk density, and it is placed in an oven to be surely dried as a preform; (6) The molten molten aluminum is injected and cooled back Mold; and (7) placing the porous metal with ceramic balls in water, and performing ultrasonic waves in a water bath method

Page 11 ^ 3668 V. Description of the invention (After the magic exhibition, the above real B and C are both the ceramic ball sophomore. Figure D is to make the experimental parameters above the pores of the finished product have a certain 2, can be cracked. The water absorption is particularly lost, so it can be implemented in the second embodiment, which has a small effect, such as the reduction of the diameter and the highest clearance. The third embodiment implements this. For the removable inspection product, ceramics are used. The degree of gasification is approximately the same as that in the program to obtain the strength, and the moderately granular process is highly acceptable. In the example, the three holes of the product are gradually increased. It can actually improve the porosity. It is about 80 ~ 85%. The balls A and 2 in the second figure are the finished products made of preform materials. The use is (a) 3mm (b) 5mm (c) 3mm and 5mm. The sodium 1mm ~ 3mm particles are 65% made of preform materials ..., PVA, CMC-Na, and water volume can be adjusted to the most appropriate combination. Ideally, with a certain degree of softness, the compaction is compacted and compacted. Particles need moderate scrolling T As for the particles breaking molecules to retain water, the private workers need to add water to contain dysprosium, which helps to maintain a convenient and / or improper pressure to form a relatively soft; 'softness' of a tight deposit. We hope to prove that The clearance can be adjusted. The adopted process and the size of Jinmai particles show that the porosity of the finished product follows the preform ::: the same, but if the crude salt is used as the preform / filled particles to about 70%, It can be seen that the bucket is a salt hole of the finished product. In the case of pottery balls, it is hoped to prove the stacking process, and the porosity of the product also has a certain degree of influence.

1223668 V. Description of the invention (9) Ceramic ball forming pressure brush pressure 1600g + 280g impact 25 times pressure 1 2 0 0g + 40 0g impact 15 times pressure 1200g + 400g impact 25 times Table-for different molding pressure and finished product porosity ㈣ Finished product Porosity 82.3% 84. 6% 8 7.5% 88. 5% It is improved when using ceramics that cannot be fixed to a ceramic table of 40 g in the use of ceramics. [Implement this cellulose with 7 ceramic balls plus In the compression molding step, a small brush was used to apply pressure, but this method provided less pressure, and j = the size of the control force. Therefore, the ceramic ball pressure molding method is changed to place a soft foam on the side, and then press the il 2 0 0g or 1600 g on the foam, and then press the fixed weight "" or hit 15 to 25 times In order to achieve the purpose of making the accumulation more compact. For the relationship between different molding pressures and the porosity of the finished product, from the above experiment ^ l " 1 " 1, from the experimental results, it can be found that increasing the pressing pressure and the number of times can indeed increase the bulk density and even the porosity of the finished product. Example 4] In the example, it is desired to prove that hydroxypropylmethyl (HPMC), which also has water retention properties, can also replace the operation provided by CMC-Na in ceramic balls (the process used and the second case in Example 3) The same (ceramic ball forming pressure is a fixed press weight of 1600g and then impacted 25 times with a weight of 280g). The results are shown in Table 2.

1223668 V. Description of the invention (ίο) There is no obvious change in the porosity of the finished product. The only difference is that during the granulation process, the surface of the particles using HPMC is relatively dry after rolling. When poured into the mold to form a stacked body, the particles are dispersed uniformly. When using CMC-Na, the surface of the particles produced is slightly moist. At this time, a small amount of A 1 203 powder can be added and shaken for a few times to make the surface of the particles dry. Therefore, the density of the stacked body, and The porosity of the finished product does not have much effect, as shown in the data in Table 2. Table 2: Comparison of Porosity of Finished Products Using CMC-Na and HPMC Composition of Ceramic Ball Powder Raw Material Porosity of Finished Product 100g Al 203 + lg bentonite + 2g CMC-Na 8 4.6 ° / 〇100gAl 203 + lg bentonite + 2g HPMC-Na 8 5.0 ° / 〇 In the formula for making ceramic balls, the added bentonite function is to provide ceramic balls with a certain strength after burning organic additives at high temperature to withstand the pressure when molten aluminum is injected. However, the excessive addition will not be conducive to the subsequent removal of ceramic balls. According to the above examples, we know that using ceramic ball particles with plasticity is easier to obtain porous aluminum products with high porosity than using hard salt particles, and that ceramic balls are also very easy to remove after grouting. Therefore, the ceramic ball has the following characteristics: (a) at the temperature of the molten aluminum injection temperature, the ceramic ball is stable and does not react with the molten aluminum; (b) has a certain strength, so it is It will not crack during the pressurization process; (c) It has considerable plasticity, so as to obtain a finished product with high porosity. Among them, ceramic balls produce strength, mainly relying on the bentonite component, providing a little sintered

Page 14 1223668 V. Description of the Invention (π) Effect. The plasticity comes from organic additives such as PVA and CMC-Na. At the temperature of molten aluminum, ceramic powders that do not react with molten aluminum can be used, such as zirconia; alumina powder is mainly used because it is the cheapest. Therefore, the invention is novel, progressive, and practical, and meets the requirements of the patent. The above are detailed descriptions and drawings of the preferred embodiments of the present invention, and are not intended to limit the present invention. All the scope of the present invention shall be subject to the following patent scopes. Any embodiment of the spirit of the patent scope and its similar changes And similar structures should be included in the present invention.

Page 15 1223668 Brief Description of Drawings The first drawing is a schematic view of forming a preform in a comparative embodiment of the present invention. The second pictures A to D are photographs of the finished product and the control group of the embodiment of the present invention. The third figure is the relationship between the particle size of the preform filler particles and the porosity of the finished product in Example 3 of the present invention. Explanation of symbols: 1 die 2 granule 3 inscription block 4 die

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Claims (1)

1223668 VI. Application for patent Fanyuan 1 • A toilet iiL ancient, + two, gap Qin, m Γ method of connected porous inscription material, to directly prepare high-porosity sheep connected porous aluminum at room temperature, the steps include. ( 1) Use plastic alumina powder. At the beginning of the mouth, with saponite hydrating agent, water-absorbing polymer knives, and man-made clay with a knife. The particles are used as the material of the stacked bed; (2) Then, the molten aluminum metal is squeezed into the pile (3) and cooled, and then Taoyan + 'and the porous porous material are washed with water. The ceramic ball is removed, and the connection is obtained. 2 The method described in item 1 of the scope of patent application, wherein the polymer binder is poly; the J-shaped porous inscription material is manufactured by granulation, and the particles produced have alcohol (PVA ) Is that the molten aluminum is cracked before casting. The strength / degree of day is not less than 3 in the car 4 method described in item 2 of the scope of patent application, in which polyvinyl alcohol (pVA) beta porous aluminum material is manufactured, while alumina, bentonite, water-absorbing ancient Eight are dissolved in water to form an aqueous solution powder, and then added to the aqueous solution, and the first eight seeds are mixed separately to form a dry dry powder and the aqueous solution in a weight ratio of i 0.5 · Z, and then granulated; Said ^ 10: 7 rooms. The method, wherein the weight of the dry powder and the aqueous solution = the manufacture of the porous aluminum material, as described in the first item of the scope of the patent application = ratio is better than 10: 6. Method in which the water-absorbing polymer is a porous aluminum material with a transportability < NO or hydroxypropyl methylcellulose \ H methyl fiber sodium salt (CMC-ceramic particles for a long time, there is, 'lies in retention When the moisture forms a stacked bed, the softness of the stacked ^ plates can be obtained, so that it is within 5 1223668 6. Application for patent scope 6 · The manufacturing method of the connected porous aluminum material according to item 1 of the patent scope, where After the stacked bed, the plastic ceramic particles that are stacked are compacted using pressure to obtain a tighter packing, which can be made into porous aluminum with higher porosity. 7 · Connected porous as described in item 1 of the scope of patent application A method for manufacturing an aluminum material, wherein the oxide powder is a-oxide particles having a particle diameter of 50 mm, and the weight ratio between the powder and bentonite is between 100: 0.5 and 100: 2. 0. 8 · The method for manufacturing a connected porous aluminum material as described in item 7 of the scope of the patent application, wherein the weight ratio between the alumina powder and bentonite is preferably 100: 1 · 0. 9 · As the item of scope of the patent application Manufacturing method of said connected porous aluminum material , Wherein the weight ratio of the water-absorbing polymer to the alumina powder is between 100: 0 · 5 to 100: 5 · 0. 1 · The connected porous aluminum material described in item 9 of the scope of patent application The manufacturing method is preferably wherein the weight ratio of the water-absorbing polymer to the alumina powder is 1 0 0: 2 · 0. Page 18