CN1080765C - Manufacturing method of sponge-like metal material with controllable pore shape and pore size structure - Google Patents

Abstract

A spongy metallic material with controllable pore shape and pore diameter is prepared through sticking raw material, laminating, baking, vacuum dipping, drying, immersing, sintering, preheating and vacuum casting. Adhering a layer of organic medium on the periphery of the organic blanks, then utilizing a lamination mode to cohere the success materials and drying the success materials, and combining the blanks to form a shaping blank with a plurality of blanks in a polymerization shape and a plurality of gap shapes distributed between the blanks; the inner holes of the spongy metal material can be mutually communicated, and the effectiveness of the spongy metal material in single or composite characteristics such as fire resistance, sound insulation, heat insulation or magnetic wave interference resistance is effectively enhanced.

Description

Manufacturing method of sponge-like metal material with controllable pore shape and pore size structure

The present invention relates to a metal material manufacturing method, in particular to a sponge-like metal material manufacturing method capable of controlling pore shape and pore diameter structure, especially an invention proposed to be extended and implemented for the manufacturing method of the parent case of Chinese patent application No. 98103046.7.

In recent years, due to the fact that porous metal materials can improve the specific gravity, compressive strength, toughness and other problems of the material, and at the same time have single or composite properties such as fire prevention, sound insulation, heat insulation, and anti-magnetic wave interference, the porous metal materials for this item The development technology has gradually attracted the attention of all walks of life at home and abroad; and for the porous metals currently developed, they can be divided into two types: foamable metals and air-permeable metals according to whether the pores are connected.

Among them, the pores of the foamed metal are individually independent and have no intercommunication, and are usually applied to lightweight structural materials (noise absorbers, shockproof materials, impact buffer materials, heat-insulating structural materials), and in terms of manufacturing methods, roughly It can be divided into foaming agent foaming method, solubility difference method, sputtering method, metal plating method, etc.; and another gas-permeable metal, whose holes are connected to each other, and this gas-permeable metal can be used to make filter Devices, catalysts, mufflers, electrode materials for heat exchanger batteries, liquid separators, liquid flow regulators, oxygen processors for purifying water, self-lubricating bearings, anti-vibration materials for LSI heat release plates, ships/aircraft/space The siding and plywood filling materials in the hull can be divided into powder metallurgy method, lost foam casting method, metal fiber sintering method, foaming agent foaming method, etc. in terms of production methods.

However, in the above-mentioned known air-permeable metal manufacturing techniques, not only must use extremely high-cost continuous casting and foaming equipment, but also there are many problems in these manufacturing methods, for example: the size, shape and volume of the formed bubble hole , pore position, strength and density, etc., cannot be effectively controlled by the above-mentioned known technologies, so even if the air-permeable metal can be produced, the fire resistance, sound insulation, heat insulation and antimagnetic properties achieved by it Effects such as waves will also be limited; in view of this technical problem that cannot be broken through, the inventor utilizes the spongy metal material manufacturing method invented by him that can control the pore shape and pore size organization, which is disclosed in Chinese Patent Application No. 98103046.7 Extending the implementation of the invention technology, in order to achieve the production of spongy metal materials that can make the pores connected and to obtain the technology that can control the density and shape of the same pores; therefore,

The object of the present invention is to: provide a kind of spongy metal material manufacturing method that can control pore shape, pore size structure, make under the premise that can control the independent pore shape of spongy metal material, pore size structure, further implement can make these The independent pore structures are interconnected into the form of interlinked pore portions, so as to improve the effectiveness of strengthening the sponge-like metal material in single or composite properties such as fire prevention, sound insulation, heat insulation or anti-magnetic wave interference.

In order to achieve the above purpose, the present invention must apply steps such as dipping, lamination, drying, vacuum dipping, drying, immersion, sintering, preheating, vacuum casting, etc. to the blank, and for the sponge-like The size and shape of the pores in the porous structure, as well as the properties of the metal material to be produced, in conjunction with the selection of blanks, selection of molten metal, and selection of refractory mud, are the same as in the original proposal, that is:

When selecting blanks, it is based on the principle of using natural materials that can be carbonized and burnt as organic matter (no environmental problems) as the blanks. The shape and size of these blanks determine the interior of the sponge tissue. The shape and volume of each hollow hole; therefore, the arrangement and connectivity of the porous distribution in the sponge tissue are achieved by cooperating with the aggregation method of the layering step.

In the layering step, in order to control the organization arrangement of the porous distribution in the sponge tissue and its interconnected shape, when layering, the blank material of the same size can be selected, and a layer of organic medium can be applied first, and then The organic medium layers are bonded to each other, and after drying, the blanks are cohesively formed into a shaped blank with a plurality of gaps, so as to facilitate the subsequent dipping process.

In terms of the selection of molten metal and the selection of refractory mud materials in the step of dipping, it is necessary to make a sponge-like metal material that belongs to a high-melting point alloy or a low-melting point alloy, and select a suitable refractory mud, and use vacuum Slurry dipping equipment, attach refractory mud to the surface of the shaped blank and dry it, so that the organic matter such as the blank in the refractory mud layer can be burned out and carbonized through the subsequent sintering process, so that the refractory mud layer can obtain the space between the previous blanks. The aggregate structure density formed by the connected pore shape and pore diameter forms a ceramic shell, and then undergoes a vacuum casting process, so that the selected metal melt can be cast into and coated in the gaps of the ceramic shell to obtain Sponge-like metal material with required connected pore shape and pore size organization.

The manufacturing method can improve the physical and mechanical properties and material of the spongy metal material, so as to control the size, shape and mass density of the through-hole structure after forming.

In order to describe the present invention in more detail, the preferred embodiments listed in conjunction with the flow chart of the accompanying drawings are described in detail as follows:

Description of drawings:

Fig. 1: is the manufacturing flow chart disclosed by the present invention;

Fig. 2: is the schematic diagram that the present invention exemplifies and selects the round blank material of same particle shape and particle size;

Fig. 3: It is a cross-sectional view of the present invention to use organic medium to coagulate, coat and laminate the blank to form a fixed-shaped blank;

Fig. 4: is the sectional view that the present invention coats a layer of refractory mud on the periphery of the organic medium layer of the stereotyped blank;

Fig. 5: It is a schematic diagram of the present invention to form a ceramic shell connected by a hole after burning off the blank and the organic medium layer;

Fig. 6: It is a schematic diagram of the present invention to place the shell connected with the holes in the vacuum die-casting equipment for vacuum casting metal material.

Please refer to Fig. 1, a method for manufacturing a spongy metal material that can control the pore shape and pore diameter structure provided by the present invention mainly includes applying the organic blank 2 to the dipping material 3, lamination 4, drying 5, vacuum Slurry dipping 8, drying 9, sintering 10, preheating 11, vacuum casting 12, finished product 13 and other steps, in order to produce a sponge-like metal material finished product with holes connected; The shape and size of material 2; where:

When selecting the embryo material 2, it is based on the principle that organic matter is used as the embryo material 2. For example, thermoplastic pellets, hard wax, or organic plant seeds or starch granules are used as the organic embryo grain 2, and these organic matter The shape of the billet 2 is preferably selected or made into a circular shape with the same shape and particle size (the circular billet is used as an example below, as shown in Figure 2), so that when the stacked layer 4 operation is carried out , can form a spongy tissue prototype with required tissue density, and use the gap 24 formed between the blanks 2 after stacking as the flow channel for the molten metal 6 (as shown in Figure 3).

After selecting the blank material 2, the operation of dipping the material 3 must be carried out, that is, the surface of the blank material 2 is adhered to a layer of organic medium 30 (as shown in Figures 1 and 3). Those that can be air-dried (such as organic colloid, organic wax) are better, so that the blanks 2 have the ability to cement, and then put these blanks 2 into a mold frame, and use the method of lamination 4 to promote the blanks 2 to stick to each other Then, it is dried 5 after being polymerized to form a stereotyped blank 28 (as shown in Figure 3 ) with a plurality of blanks 2 aggregated shapes and a plurality of gaps 24 distributed therebetween.

As shown in Figure 4, after forming the required stereotyped blank 28, it is necessary to apply the vacuum dipping process 8 of coating the refractory mud 7 to the stereotyped blank 28, and for the selection of molten metal 6 and In the process of selecting refractory mud 7, it can be divided into A type of refractory mud 71 that must be selected when using high melting point alloy 61 type of molten metal 6, or type B that must be selected when using low melting point alloy 62 type of molten metal 6 Type A refractory mud 72 (as shown in Table 1); No matter it is Type A refractory mud 71 or Type B refractory mud 72, the following conditions must be met:

1. Resistant to the rapid heat erosion of molten metal.

2. Small thermal expansion to ensure the stability of the thickness and size of the refractory layer.

3. Good high temperature strength.

4. No decomposition or crystal transformation can occur at high temperature.

5. It should have good fusion with molten metal.

Based on the above requirements, the refractory mud composition and temperature resistance characteristics in the following table 1 can be selected:

Table 1: is the comparison table of the powder ratio and temperature resistance characteristics of various refractory mud components disclosed by the present invention. ingredients Al ₂ O _{3 ZrO2} SiO ₂ Na ₂ O _{Fe2O3 _} TiO ₂ CaO MgO Melting point (°C) quartz 0.11 -- 99.8 -- 0.033 0.022 Tr Tr 1700 Fused Silica 0.05 -- 99.9 -- 0.02 0.015 0.01 0.005 (same as above) Fused alumina 99.5 -- 0.3 0.35 0.03 0.015 0.05 0.005 2050 Aluminum Oxide (Crystalline) 99.0 -- 0.1 0.02 0.4 -- 0.07 -- (same as above) Zircon sand (A) 65.0 34.0 -- 0.1 0.25 -- -- 2300 Zircon sand (B) 0.79 Min66.32 Max32.23 -- Max0.04 Max0.2 -- -- (same as above)

Continued Table 1 Zirconia (stabilized) 0.39 94.6 0.35 -- 0.19 0.21 3.52 0.46 2690 calcium aluminum oxide 79.0 -- 0.1 0.5 0.3 -- 18.0 0.4 1700 burnt clay 41.6 -- 52.8 1.2 1.5 2.5 0.3 0.4 -- Flint particles 47.5 -- 47.7 0.9 (totalAlkali) 1.1 2.5 0.2 0.2 -- Mullite melting 76.2 -- 23.0 0.44 0.13 0.11 0.05 0.05 1810 decomposition Mullite 73.5 -- 22.4 -- 0.9 3.2 -- -- (same as above) Kyanite 57～60 -- 37～41 -- 0.08～0.4 1.2 0.3 0.3 1550 communion Malay Sarawak (Molochite) 42～43 -- 54～55 Na ₂ O ₁ K ₂ O _15～20 0.75 0.08 0.1 0.1 --

Of course, in order to make all kinds of refractory powder components in Table 1 can be phase-polymerized into mud 7, it is absolutely necessary to use binder 73, such as using water glass (Sodium Silicate, Na ₂ SiO ₃ ), ethyl silicate Ethyl Silicate or Colloidal Silicate (SiO ₂ ), etc., these binders 73 all use the silica gel (Silica Gel) in their components to do the bonding work; in principle, the bonding used in this additional invention Agent 73 tends to use silicone fluid that is easy to obtain and has a simple procedure, because silicone fluid has been used in precision casting for many years and can be purchased easily. At the same time, the chemical properties of silicone fluid are very stable unless it is stored in an environment below freezing point. In addition, as long as it is dehydrated and dried, it will not absorb water to restore its original properties. Therefore, the silica gel liquid is extremely stable in storage and use, and it is the silica gel liquid used as the binder in this invention. 73 main reasons.

More specifically, when the refractory alloy 61 is used as the molten metal 6 in the present invention, the composition type of the refractory mud 71 of type A can be selected from the following Table 2:

Table 2: Composition and traits of A kind of mud resistance.

In other words, when the low-melting point alloy 62 is used as the molten metal 6 in the present invention, the composition of the B type refractory mud 72 is to select a gypsum refractory material, that is, the gypsum itself has two molecules of crystallization water (CaSO ₄ 2H ₂ O), if it is used as a refractory material, depending on the working time and solidification time, part of the water in the gypsum is removed, and the remaining water is between 1 and 1 ^1/2 molecules [CaSO ₄ ( 1～1 ^1/2 )H ₂ O] to become plaster of paris, which can be prepared by adding water during use, and is usually available on the market for use.

After selecting the appropriate refractory mud 7 according to the type and characteristics of the molten metal 6, the type A refractory mud 71 selected for the high melting point alloy 61 must be prepared as follows:

a. Use the propeller to rotate at a high speed of 1725rpm in the mixing tank, mix the type A refractory mud 71 and the binder 73 until uniform, and then put it into the mixing tank to stir and mix, so as to facilitate the subsequent supply of vacuum slurry 8 for use. In the meantime, it must be noted that once the mud has been prepared, it is best to keep the mixing tank running at a slow speed before vacuum dipping 8, so that the binder 73 and the A-type refractory mud 71 are often kept in the most uniform mixing situation. .

b. Viscosity control of mud: Generally, Zahn Cup (Zahn Cup) 4 ^# and 5 ^# are used. If Zahn Cup 5 ^# is used for modulation, the viscosity obtained between 9 and 30 seconds is more suitable ( Coordination see Table 2).

c. Add wetting agent 74 (Wetting Agent): wetting agent 74 is a kind of surfactant, the main purpose of adding wetting agent 74 in A refractory mud 71 is to make the refractory mud more easily adhere to the organic medium 30 (such as : thermoplastic, hard wax, organic starch). Generally, if ethyl silicate is used as the binder 73, there is no need to add a wetting agent 74 because of its better wettability.

d. Add defoamer 75 (Antifoam): In order to make the air bubbles contained in the mud disappear, add octanol (n-Octyl alcohol), this agent will not gel the mud, so it has stability in use.

e. Add Polyvinyl Acetate 76 (Polyvinyl Acetate): it is used to improve the wet strength of Type A refractory mud 71; Wax phenomenon; and in the subsequent sintering 11 process, it has the effect of removing organic matter.

After the above-mentioned suitable refractory mud 7 is prepared, the equipment for vacuum dipping 8 must be used to place the shaped prototype 28 into the equipment, and the gas is extracted from the equipment to form a vacuum state, and then the refractory mud 7 is injected to The refractory mud 7 can fully penetrate into the gap 24 of the shaped blank 28; then take out the shaped blank 28 that has completed the vacuum dipping 8 operation, and dry 9 at a temperature of 130°C ± 20°C to promote The refractory mud 7 on the periphery of the shaped blank 28 can form a hardened refractory layer 70 .

After the above-mentioned steps are completed, the blank 28 in the refractory layer 70 and the organic medium 30 must be carbonized and burned by sintering 11 at a high temperature of 800°C to 1800°C; The layer 70 forms a strong ceramic shell 29 after sintering, and the ceramic shell 29 forms a distribution pattern with connected holes 25 and necks 26, while the holes 25 and necks of the shell 29 26, there are still slits 24 (as shown in FIG. 5 ) distributed.

Subsequently, the vacuum casting 13 equipment with constant temperature heating capability is used to implement the operation of preheating 12 and pouring molten metal 6 (as shown in FIG. 6 ); wherein, before performing molten metal 6 pouring, Utilizing the mold cavity 131 in the vacuum casting equipment to heat at a constant temperature, and then preheating 12 the ceramic shell 29 that is placed in the mold cavity 131 in the shape of a sponge tissue, is an extremely necessary procedure, because after preheating 12 earlier, it can be used The molten metal 6 using the gap 24 of the casing 29 (as shown in FIG. 3 ) as a flow channel can flow easily and be filled in the gap 24 by casting, especially the low melting point alloy 62 is used as the molten metal 6 The fluidity at the time must be promoted by the action of the previous preheating 12 of the housing 29 to promote the smooth progress of its vacuum casting, so it is absolutely helpful.

Furthermore, in the process of vacuum casting 13 (as shown in FIG. 6 ), the mold cavity 131 contains the ceramic casting shell 29 which has been placed in place, and the gas is extracted together to form a vacuum state, so as to facilitate the injection of molten metal. , can improve the circulation of the melt in each gap 24 in the housing 29, and will be described.

The finished product 14 of spongy metal material after die-casting through the above-mentioned steps has its double-sided walls covered and leveled by the solidified molten metal 6 , and the solidified molten metal 6 fills up the gap 24 , The structure form of the spongy metal material finished product 14 is that the through hole 25 and the neck 26 formed inside are covered by the solidified metal solution 6 . When the finished product 14 is used as a sound insulation wall, the double side walls of the finished product 14 can be polished to expose the communicating hole 25 and the neck 26, which can enhance its sound-absorbing effect. Of course, in some application occasions where fire protection or heat insulation effects are emphasized, the double-sided walls of the finished product 14 do not need to be ground and polished to achieve the effect of heat insulation. It is also known that no matter whether the double-side walls of the finished product 14 are subjected to grinding and polishing treatment, it still retains the original single or composite properties such as compression resistance, toughness, fire resistance, sound insulation, heat insulation, and anti-magnetic wave interference. In addition, and due to the connectivity of the internal holes, the sponge-like metal material will be more remarkable in the ability to isolate sound waves.

In summary, the manufacturing method of the spongy metal material with controllable pore shape and pore diameter structure provided by the present invention utilizes the cohesion of blanks into a fixed-shaped blank to promote the internal pores of the spongy metal material to be mutually Connected forming technology has effectively improved the practicability and utilization of sponge-like metal materials, so it should have high-tech utilization value, so an application for additional invention was filed according to law.

Claims (5)

1. A manufacturing method of spongy metal materials that can control the pore shape and pore size structure. It is a method that must first select blanks, metal melts and refractory mud, and then carry out dipping, lamination, and drying. To make the required shaped prototype, and then go through the steps of vacuum dipping, drying, sintering, preheating and vacuum casting to obtain a sponge-like metal material with controllable pore shape, pore size structure and interlinked pores; wherein: The raw material is composed of organic matter with appropriate shape and quantity ratio according to the size and shape of the hole to be formed; The refractory mud is prepared separately according to whether the metal material to be made is a high-melting point alloy or a low-melting point alloy; Its characteristics include: Attach a layer of organic medium to the periphery of these organic blanks, and then use the layering method to glue the blanks and then dry them, so that the blanks are combined to form a polymeric appearance with many blanks and a large number of gaps distributed among them. the finalized prototype; Depending on whether the metal material to be made of the shaped prototype is a high-melting point alloy or a low-melting point alloy, a suitable refractory mud is selected for vacuum dipping and drying, so that the refractory mud can be coated on the shaped prototype. The periphery of the parts and the surface layer of the gap, and hardened to form a refractory layer; The molded part coated with organic medium dipping material and refractory layer is sintered at a high temperature of 800°C-1800°C to carbonize and burn off the inner blank and the organic medium layer to obtain the required connected holes and Shaped ceramic shell with neck distribution density; Vacuum casting equipment is used to preheat the shaped casing, and then vacuum die-casting of molten metal is performed on the casing to make a porous metal material product with interconnected pores. 2. The manufacturing method of the spongy metal material with controllable pore shape and pore size structure according to claim 1, characterized in that: the blanks are preferably those with the same circular particle size. 3. The manufacturing method of the spongy metal material with controllable pore shape and pore diameter structure according to claim 1, characterized in that: the organic medium is made of organic colloid or organic wax, which is cohesive, easy to dry, Those that can be burned are better. 4. The manufacturing method of the spongy metal material with controllable pore shape and pore diameter structure according to claim 1, characterized in that: the shell's hole and the periphery of the neck are distributed with gaps. 5. The manufacturing method of spongy metal material with controllable pore shape and pore diameter structure according to claim 1, characterized in that: the vacuum casting process is used to fill the gap of the shell with molten metal and cover it The hole and the neck of the casing are made of porous metal material with holes connected to each other.

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