Preparation method of foam metal

Abstract

The invention discloses a preparation method of foam metal, and belongs to the technical field of porous metal preparation. The method comprises the following steps: forming a single-layer foam half-hole structure by a metal sheet through a mold pressing process, and carrying out closed hole combination after surface treatment and functional material filling to form a single-layer foam structure; and the single-layer foam structures are stacked and combined in a three-dimensional space, and the foam metal is obtained. Metal sheets made of different materials are selected according to product purposes, and different types of molds are selected for die forming according to the shapes of the air holes and the materials of the metal sheets; different surface treatment processes or functional materials are selected for filling according to product purposes, and the single-layer foam structures are combined in a welding mode, a riveting mode, a gluing mode, a high-temperature sintering mode and the like. The size and shape of the air holes are effectively controlled through mold design, the process period is greatly shortened, functional material filling can be achieved in the air holes, and a single-layer foam half-hole structure can endow the foam metal with a new function through surface treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of porous metal preparation, and in particular relates to a method for preparing foamed metal. Background Art

[0002] Foam metal has the dual properties of metal material structure and porous material function, and therefore has a wide range of applications in industrial structure, biomedicine, filtration and separation, catalysis, electrodes, sound absorption and noise reduction, and heat exchange.

[0003] The main preparation methods of foam metal include adding pore-forming agent, melt foaming, electrophoretic deposition, etc. The porous metal prepared by adding pore-forming agent has low porosity, and the pore size and distribution are difficult to control; the pore structure of melt foaming is difficult to control, the preparation cycle is long, and the preparation process of electrophoretic deposition is complicated, resulting in high cost of foam metal process and difficulty in large-scale industrialization. Therefore, it is very important to find a kind of foam metal preparation process with precise control of pore structure and simple process.

[0004] From a structural point of view, foam metal can be considered as spherical pores irregularly stacked and arranged in three-dimensional space, with metal materials filled between the spherical pores. After slicing the foam metal, it was found that when the thickness of a single-layer slice is half the average pore size, the two cut surfaces of the single-layer foam are covered with a large number of hemispherical holes. Its structure is similar to that of dense ceramics, with hemispherical holes with a radius twice the thickness of the dense ceramic "carved" at different positions on both sides. From a process point of view, this structure can be achieved by molding hemispherical holes in metal sheets and then nesting them, and then combining the single-layer foam structure to achieve the reconstruction of the foam structure in three-dimensional space. Therefore, the preparation of foam metal by stacking single-layer foam structures undoubtedly has great practical production value. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a method for preparing foam metal to solve the technical problems in the existing foam metal preparation process that the pore shape and size are difficult to accurately control, the production cost is high, the process cycle is long, and the functionality and performance need to be improved.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: The invention discloses a method for preparing foamed metal, comprising the following steps: Step 1: Form a single-layer foam semi-porous structure through a molding process on the metal sheet, and then perform closed-cell bonding after surface treatment and functional material filling to form a single-layer foam structure; Step 2: Stack and combine the single-layer foam structure in three-dimensional space to obtain foam metal.

[0007] Preferably, in step 1, the metal sheet includes aluminum, aluminum alloy, copper, copper alloy, nickel-based alloy, stainless steel, pure titanium, titanium alloy, non-ferrous metal or rare metal; and the thickness of the metal sheet is 0.1-1 mm.

[0008] Preferably, in step 1, the metal sheet adopts a mesh or porous structure.

[0009] Preferably, in step 1, the shape of the pores in the single-layer foam structure includes pebble-shaped, cylindrical or spherical; when the pores are spherical, the diameter of the spherical pores is 0.2-10 mm.

[0010] Preferably, in step 1, the material of the mold is ceramic, stainless steel or carbon steel.

[0011] Preferably, in step one, the surface treatment includes mechanical surface treatment, electrochemical surface treatment, chemical surface treatment, thermal spraying, vacuum plating, vapor deposition technology or laser surface treatment.

[0012] Preferably, in step one, the functional filling material includes aerogel, short fibers or whiskers.

[0013] Preferably, in step one, the closed-cell bonding includes welding, riveting, organic adhesive bonding or high-temperature sintering.

[0014] Preferably, in step 2, when the pores in the single-layer foam structure are spherical pores, they are stacked in three-dimensional space in a body-centered cubic, face-centered cubic or hexagonal close-packed arrangement mode.

[0015] Preferably, in step 2, the stacking bonding method includes welding, riveting, bonding with an organic binder or high-temperature sintering.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a method for preparing foam metal. The foam metal is formed by stacking a single-layer foam semi-porous structure. This step not only simplifies the complex process of traditional foam metal manufacturing, but also improves the manufacturing pore accuracy and process controllability. The molding process can accurately control the pore size and pore shape of the foam metal, thereby meeting the requirements of different fields for the pore parameters of the foam metal. The surface treatment of the single-layer foam semi-porous structure and the filling of the pores with different functional materials give the foam metal different properties and expand its application range. The foam metal after three-dimensional spatial stacking and arrangement not only retains the advantages of the single-layer foam structure, but also further enhances the overall performance through multi-layer stacking. The mold design realizes effective control of the pore size and shape, avoiding the difficulty of difficult control of the pore structure of the foam metal prepared by the traditional casting foaming method; avoiding the dependence of the high-temperature pore structure formation process on the melt parameters, greatly reducing the process cycle; avoiding the shrinkage caused by high-temperature treatment that causes a large change in the shape of the product, and having high flexibility and customizability. By adjusting the molding process parameters, the surface treatment method of the single-layer foam semi-porous structure and the parameters of the pore filling material, foam metal products with different performance requirements can be produced to meet the special requirements of foam metal performance in different fields, and promote large-scale, low-cost and rapid manufacturing of foam metal.

[0017] Furthermore, the single-layer foam semi-porous structure can give the foam metal many new functions through surface treatment; Furthermore, the pores can be filled with functional materials, such as aerogel or short fibers, to give the product excellent energy-saving, sound-absorbing and sound-insulating properties.

[0018] The foamed aluminum prepared by the preparation method disclosed in the present invention has precisely controllable pore size and size distribution, is light in weight, has good thermal insulation performance, excellent sound absorption and sound insulation, and is economical and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention discloses a flow chart of a method for preparing a foamed metal. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0021] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings: The invention discloses a method for preparing foamed metal, comprising the following steps: Step 1: using a metal sheet to form a single-layer foam semi-porous structure through a molding process, and then performing a surface treatment, and then performing closed-cell bonding on the single-layer foam semi-porous structure to form a single-layer foam structure; Step 2: Stack and combine the single-layer foam structure in three-dimensional space to obtain foam metal.

[0023] Furthermore, the metal foam may be closed-cell or open-cell.

[0024] Furthermore, the metal sheet can be mesh or porous; the mesh or porous metal sheet can increase the porosity and specific surface area of ​​the foam metal, thereby improving its heat insulation, sound absorption, filtering and other properties. It is conducive to the formation of pores in the molding process, and further optimizes the structure and performance of the foam metal.

[0025] Furthermore, the shape of the pores of the single-layer foam structure is pebble-shaped, cylindrical, spherical, etc. When the pores are spherical, the diameter of the spherical pores is 0.2-10 mm, and a foam metal with a uniform pore structure can be prepared. Spherical pores of different diameters and pores of different shapes can meet the special requirements of foam metal performance in different fields.

[0026] Furthermore, the mold used in the molding process is made of ceramic, stainless steel, carbon steel, etc., and the molding pressure and mold material are determined according to the product composition. This molding process can accurately control the pore size and pore shape of the foam metal, improving the accuracy and consistency of the product size. The structure of the foam metal is made more diverse and controllable, meeting the special requirements of the foam metal performance in different fields.

[0027] Furthermore, the spherical pore single-layer foam structure can be stacked and combined in space according to spherical pore body-centered cubic, face-centered cubic, close-packed hexagonal and other stacking modes.

[0028] Furthermore, the thickness of the metal sheet is between 0.1-1 mm.

[0029] Furthermore, the diameter of the spherical holes in the single-layer foam structure is between 0.2-10 mm, and the specific size depends on the product application market.

[0030] Furthermore, the single-layer foam semi-porous structure can undergo different surface treatments, including mechanical surface treatment, electrochemical surface treatment, chemical surface treatment, thermal spraying, vacuum plating, vapor deposition technology, laser surface treatment and other surface treatment methods, which can give the foam metal new functions, such as corrosion resistance, electrical conductivity, thermal conductivity, etc., further expanding its application range.

[0031] Furthermore, the metal sheet can be made of aluminum and aluminum alloys, copper and copper alloys, nickel-based alloys, stainless steel, pure titanium and titanium alloys, and other steel, nonferrous metals, rare metals, etc. By specifying the material of the metal sheet as aluminum, aluminum alloys, copper, copper alloys, etc., and the thickness as 0.1-1 mm, foam metals with different properties and characteristics can be prepared to meet the needs of different fields.

[0032] Furthermore, the material of the foam metal must have a certain plasticity, and the materials include steel, non-ferrous metals and rare metals.

[0033] Furthermore, the closed-cell bonding methods of the single-layer foam semi-porous structure include welding, riveting, organic adhesives, high-temperature sintering, etc.; a large amount of aerogel, short fibers and whiskers can be added when the single-layer foam semi-porous structure is closed-celled to reduce the thermal conductivity and improve the sound insulation and sound absorption performance. The addition of short fibers, whiskers and aerogels can enhance the sound insulation, sound absorption and energy-saving performance of the foam metal. This design enables the foam metal to better meet the needs of specific fields.

[0034] Furthermore, the stacking and bonding of the single-layer foam structure can be carried out by welding, riveting, adhesive, high-temperature sintering, etc. Different bonding methods correspond to the performance requirements in different fields, which can ensure the firm bonding between the single-layer foam structures and improve the stability and durability of the foam metal.

[0035] See also Figure 1 This is a flow chart of a method for preparing a foam metal disclosed in the present invention; a single-layer foam semi-porous structure is formed by a die pressing process using a 0.2 mm thick pure aluminum sheet, and the diameter of the spherical pores of the mold is 4 mm; after surface treatment, closed-cell bonding is performed to form a single-layer foam structure; the single-layer foam structure is stacked and bonded in three-dimensional space to obtain foam aluminum. The volume density of foam aluminum is 0.5846 g / cm 3, the average sound absorption coefficient is ≥0.60 (125-4000Hz), and the average sound insulation is 20-40dB (measured in the frequency range of 125-4000Hz). The prepared foam aluminum is mainly used as a sound insulation screen for urban roads.

[0036] The present invention discloses a method for preparing foamed metal, wherein metal sheets of different materials are selected according to the purpose, different metal molds are selected according to the pore shape and metal material for molded plastic forming, and then surface treatment is performed according to different performance requirements, and the obtained single-layer foam structure is stacked and combined by welding, riveting, gluing, etc. The present invention realizes effective control of pore size and shape through mold design, greatly shortens the traditional high-temperature foaming process cycle, and the pores can be filled with functional materials (aerogel, fiber, whisker, etc.), and the single-layer surface can also be treated to give the foam new functions.

[0037] Example 1 A method for preparing a foamed metal comprises the following steps: Step 1: Use a ceramic mold to mold a 1mm thick aluminum sheet to form a single-layer foam semi-porous structure. After the surface is shot peened, a welding process is used to perform closed-cell bonding to form a single-layer foam structure with spherical pores; Step 2: Stack and arrange the single-layer foam structure in three-dimensional space to obtain foam aluminum, and the single-layer foam structure is connected by welding.

[0038] Example 2 A method for preparing a foamed metal comprises the following steps: Step 1: Use a stainless steel mold to mold an aluminum alloy sheet with a thickness of 0.5 mm to form a single-layer foam semi-porous structure. After the surface is anodized, a riveting process is used for closed-cell bonding, and short fibers are added to form a single-layer foam structure with pebble-like pores; Step 2: stacking the single-layer foam structures in three-dimensional space to obtain foam aluminum alloy, and the single-layer foam structures are connected by riveting.

[0039] Example 3 A method for preparing a foamed metal comprises the following steps: Step 1: Use a carbon steel mold to mold a 0.3 mm thick copper sheet to form a single-layer foam semi-porous structure, use an organic binder for closed-cell bonding, add aerogel, and form a single-layer foam structure with cylindrical pores; Step 2: stacking the single-layer foam structure in three-dimensional space to obtain foam copper, and the single-layer foam structure is bonded by an organic binder.

[0040] Example 4 A method for preparing a foamed metal comprises the following steps: Step 1: Use a ceramic mold to mold a copper alloy sheet with a thickness of 0.2 mm to form a single-layer foam semi-porous structure, spray an inorganic coating on the surface for closed-cell bonding, and add whiskers inside the pores to form a single-layer foam structure with spherical pores. The diameter of the spherical holes is 1 mm.

[0041] Step 2: stacking the single-layer foam structure in three-dimensional space to obtain a foam copper alloy, and using an inorganic coating to combine the single-layer foam structure.

[0042] Example 5 A method for preparing a foamed metal comprises the following steps: Step 1: Use a stainless steel mold to mold a porous nickel-based alloy sheet into a single-layer foam semi-porous structure, and after vacuum plating, use a welding process to perform closed-cell bonding to form an open-cell single-layer foam structure with spherical pores. The diameter of the spherical pores is 0.2 mm. Step 2: stacking the open-cell single-layer foam structure in three-dimensional space to obtain an open-cell foam nickel-based alloy, and combining them by welding process.

[0043] Example 6 A method for preparing a foamed metal comprises the following steps: Step 1: Use a stainless steel mold to mold a 0.1 mm thick stainless steel sheet to form a single-layer foam semi-porous structure. After vapor deposition treatment, use a welding process to perform closed-cell bonding, and add aerogel inside the pores to form a single-layer foam structure with cylindrical pores; Step 2: Stack the single-layer foam structure in three-dimensional space to obtain foam stainless steel, and combine them using welding technology.

[0044] Example 7 A method for preparing a foamed metal comprises the following steps: Step 1: Use a stainless steel mold to mold a 0.5mm thick porous pure titanium sheet into a single-layer foam semi-porous structure, and then use a laser welding process to perform closed-cell bonding to form a single-layer foam structure with pores in the shape of pebbles; Step 2: Stack the single-layer foam structure in three-dimensional space to obtain open-pore titanium foam, and combine them using laser welding technology.

[0045] Example 8 A method for preparing a foamed metal comprises the following steps: Step 1: Use a stainless steel mold to mold a 0.3mm thick porous titanium alloy sheet to form a single-layer foam semi-porous structure, and use a laser welding process to perform closed-cell bonding to form a single-layer foam structure with cylindrical pores; Step 2: Stack the single-layer foam structure in three-dimensional space to obtain foam titanium alloy, and combine them using laser welding technology.

[0046] Example 9 A method for preparing a foamed metal comprises the following steps: Step 1: Use a stainless steel mold to mold a steel sheet with a thickness of 0.2 mm to form a single-layer foam semi-porous structure. After the surface is shot peened, it is welded to form a closed-cell structure, and aerogel is added to form a single-layer foam structure with spherical pores; the diameter of the spherical hole is 10 mm.

[0047] Step 2: The single-layer foam structures are stacked in three-dimensional space to obtain foam steel, and the single-layer foam structures are combined by welding.

[0048] Example 10 A method for preparing a foamed metal comprises the following steps: Step 1: Use a stainless steel mold to mold a porous steel sheet with a thickness of 0.2 mm to form a single-layer foam semi-porous structure. After the surface is treated by an anodizing process, it is welded and combined, and aerogel is added to form a single-layer foam structure with spherical pores; the diameter of the spherical hole is 7 mm.

[0049] Step 2: stacking the single-layer foam structure in three-dimensional space to obtain open-pore foam steel, and combining the single-layer foam structure by welding.

[0050] The present invention discloses a method for preparing foam metal, wherein a metal sheet is formed into a single-layer foam semi-porous structure through a molding process, and after different surface treatments or functional material filling, closed-cell bonding is performed to form a single-layer foam structure; the single-layer foam structure is stacked and arranged in three-dimensional space and then combined to obtain foam metal. Metal sheets of different materials are selected according to the purpose, and different metal molds are selected for molding plastic forming according to the pore shape and metal material. After at least one of surface treatment and functional material filling of the single-layer foam semi-porous structure is performed according to different performances, the single-layer foam structures can be combined by welding, riveting, gluing, etc. The present invention realizes effective control of pore size and shape through mold design, greatly shortens the traditional high-temperature foaming process cycle, and can realize functional material filling inside the pores, aerogel, fiber material filling, and the single-layer surface can also be given new functions by surface treatment.

[0051] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a foamed metal, characterized in that: The following steps are involved: Step 1: Form a single-layer foam semi-porous structure through a molding process on the metal sheet, and after surface treatment and filling with functional materials, perform closed-cell bonding to form a single-layer foam structure; Step 2: Stack and combine the single-layer foam structure in three-dimensional space to obtain foam metal.

2. The method for preparing a foamed metal according to claim 1, characterized in that: In step 1, the metal sheet includes aluminum, aluminum alloy, copper, copper alloy, nickel-based alloy, stainless steel, pure titanium, titanium alloy, non-ferrous metal or rare metal; the thickness of the metal sheet is 0.1-1 mm.

3. The method for preparing a foamed metal according to claim 1, characterized in that: In step 1, the metal sheet adopts a mesh or porous structure.

4. The method for preparing a foamed metal according to claim 1, characterized in that: In step 1, the shapes of the pores in the single-layer foam structure include pebble-shaped, cylindrical or spherical; when the pores are spherical, the diameter of the spherical pores is 0.2-10 mm.

5. The method for preparing a foamed metal according to claim 1, characterized in that: In step 1, the material of the mold is ceramic, stainless steel or carbon steel.

6. The method for preparing a foamed metal according to claim 1, characterized in that: In step 1, the surface treatment includes mechanical surface treatment, electrochemical surface treatment, chemical surface treatment, thermal spraying, vacuum plating, vapor deposition technology or laser surface treatment.

7. The method for preparing a foamed metal according to claim 1, characterized in that: In step one, the functional material includes aerogel, short fibers or whiskers.

8. The method for preparing a foamed metal according to claim 1, characterized in that: In step one, the closed-cell bonding includes welding, riveting, organic adhesive bonding or high-temperature sintering.

9. The method for preparing a foamed metal according to claim 1, characterized in that: In step 2, when the pores of the single-layer foam structure are spherical pores, they are stacked in three-dimensional space according to a body-centered cubic, face-centered cubic or close-packed hexagonal arrangement mode.

10. The method for preparing a foamed metal according to claim 1, characterized in that: In step 2, the stacking and bonding method includes welding, riveting, bonding with an organic adhesive or high-temperature sintering.

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