Aluminum-based composite board, preparation method and application

Abstract

The application relates to the technical field of aluminum-based material processing, in particular to an aluminum-based composite plate, a preparation method and application. The preparation method comprises the following steps: firstly, uniformly mixing aluminum alloy powder and reinforced particles after surface etching treatment, then adding a binder, uniformly mixing to obtain a solid powder; secondly, pressing the solid powder into a blank, sintering the blank, and then performing die shaping to obtain a shaped sample; thirdly, sequentially performing solid solution treatment and quenching treatment on the shaped sample, and then performing natural aging treatment to obtain an aluminum-based composite material; and fourthly, performing rolling treatment on the aluminum-based composite material to obtain an aluminum-based composite plate with a thickness of 0.5-1 mm. The aluminum-based composite plate is prepared by the preparation method. The application is the application of the aluminum-based composite plate in the preparation of a heat exchanger. The aluminum-based composite plate prepared by the application has the performance advantages of light weight, high thermal conductivity and high rigidity, and can be used for preparing a heat exchanger.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum-based material processing, in particular to an aluminum-based composite plate, a preparation method and application. BACKGROUND

[0002] Heat exchangers are often used in aerospace equipment to meet heat exchange requirements. The heat exchangers used in aerospace equipment often need to have the advantages of lightweight, high stiffness and high thermal conductivity. However, some of the existing heat exchangers are made of stainless steel materials, which has the problem of poor thermal conductivity. Some of the existing heat exchangers are made of aluminum alloy materials, which can meet the requirement of lightweight, but the stiffness of the aluminum alloy material is low, and it is easy to deform when the heat exchange channel is formed by stamping, resulting in a decrease in yield.

[0003] In view of the above, it is necessary to provide an aluminum-based composite plate, a preparation method and application to solve the problems of poor thermal conductivity and low stiffness of the existing heat exchangers. SUMMARY

[0004] The present application aims to provide an aluminum-based composite plate, a preparation method and application, and the specific technical solutions are as follows:

[0005] In the first aspect, the present application provides a preparation method of an aluminum-based composite plate, comprising:

[0006] Step S1, first mix the aluminum alloy powder and the reinforced particles after surface etching treatment, then add a binder, and obtain a solid powder after mixing;

[0007] The aluminum alloy powder comprises the following raw material components by mass percentage: manganese 0.2%-0.8%, copper 0.1%-0.3%, magnesium 0.3%-0.8%, zinc 0.2%-0.5%, chromium 0.15%-0.35%, and the balance of aluminum;

[0008] The reinforced particles comprise at least one of TiN and TiCN;

[0009] Step S2, first press the solid powder into a billet, then sinter the billet, and then perform die shaping to obtain a shaped sample;

[0010] Step S3, sequentially perform solid solution treatment and quenching treatment on the shaped sample, and then perform natural aging treatment to obtain an aluminum-based composite material;

[0011] Step S4, perform rolling treatment on the aluminum-based composite material to obtain an aluminum-based composite plate with a thickness of 0.5-1mm.

[0012] Optionally, in step S1, the surface etching treatment comprises adding weak acid into the ammonium bifluoride solution, then immersing the reinforcing particles into the ammonium bifluoride solution, and after mixing, etching the surface of the reinforcing particles for 20-50s; and then cleaning and drying the reinforcing particles after surface etching treatment. The present application uses ammonium bifluoride and weak acid in combination, i.e. through slow supply of hydrogen ions by weak acid and action with ammonium bifluoride to provide micro-acid etching conditions, which on the one hand ensures safe etching process, and on the other hand facilitates gradual etching of the surface of the reinforcing particles, improves the surface roughness of the reinforcing particles, and realizes better composite effect between the reinforcing particles and the aluminum alloy powder.

[0013] Optionally, the concentration of the ammonium bifluoride solution is 0.2-0.5mol / L; the weak acid comprises phosphoric acid; the concentration of the phosphoric acid is 0.1-0.2mol / L; and the particle size of the reinforcing particles before the surface etching treatment is 500-1000nm.

[0014] Optionally, in the solid powder, the aluminum alloy powder accounts for 93.5%-97.5%, the reinforcing particles account for 2%-5%, and the binder accounts for 0.5%-1.5% by mass percentage.

[0015] Optionally, in step S2, the pressure used in pressing is 20-100MPa to ensure that the solid powder is pressed into a green body; if the pressure is too small, the solid powder may be difficult to press into a shape, or the green body may have low strength and be prone to powder collapse at the edge after pressing; the sintering temperature used in sintering treatment is 550-600℃, and the sintering time is 60-120min; if the sintering temperature is too high, the green body may be coarsened, the toughness may be reduced, and the brittleness may be increased; if the sintering temperature is too low, the green body may not be completely alloyed, and the strength may be reduced; and the die pressing temperature used in die pressing shaping is 450-500℃, so that the green body is soft and easy to shape.

[0016] Optionally, in step S3, the solid solution temperature used in solid solution treatment is 480-520℃, and the solid solution time is 2-10h; the quenching medium used in quenching treatment is heat conducting oil, the quenching temperature is 25-45℃, and the quenching time is 30-60s; and the natural aging treatment is to place the shaped sample at room temperature for more than 72h.

[0017] Optionally, in step S4, the rolling treatment adopts multi-pass rolling, and the deformation of each pass is not higher than 1mm, because the aluminum-based composite material is a powder metallurgy material and is relatively brittle, and if a too large rolling deformation is used, cracks or internal stress concentration may be easily generated; and the rolling temperature used in rolling treatment is 400-450℃.

[0018] In a second aspect, the present application provides an aluminum-based composite sheet prepared by the preparation method of the aluminum-based composite sheet.

[0019] In a third aspect, the present application provides an application of the aluminum-based composite sheet, and the application of the aluminum-based composite sheet in manufacturing a heat exchanger.

[0020] The technical scheme of the present application has at least the following beneficial effects:

[0021] The preparation method of the aluminum-based composite sheet provided by the present application has the performance advantages of light weight, high thermal conductivity and high stiffness, and the aluminum-based composite sheet prepared by the method can be used to manufacture a heat exchanger and used in aerospace equipment, thereby solving the problems of poor thermal conductivity and low stiffness of existing heat exchangers. Specifically, the aluminum alloy powder used in step S1 includes the following raw material components by mass percentage: manganese 0.2%-0.8%, copper 0.1%-0.3%, magnesium 0.3%-0.8%, zinc 0.2%-0.5%, chromium 0.15%-0.35%, and the balance of aluminum; the aluminum alloy powder with the above composition has high thermal conductivity; the present application also uses reinforcing particles in step S1, which include at least one of TiN and TiCN, which not only facilitates the improvement of the stiffness of the aluminum-based composite sheet, but also facilitates the improvement of the thermal conductivity of the aluminum-based composite sheet. TiN and TiCN have good thermal and electrical conductivity, and at the same time, the titanium compound in the aluminum alloy powder is oxidized and reduced to form titanium metal, and the titanium metal has alloy strengthening effect on the aluminum alloy matrix; the surface etching treatment of the reinforcing particles facilitates the improvement of the surface roughness of the reinforcing particles, and achieves better composite effect between the reinforcing particles and the aluminum alloy powder; the sintering treatment of the blank in step S2 facilitates the improvement of the toughness of the blank and the reduction of the brittleness of the blank, and prepares for the subsequent rolling and thinning of the aluminum-based composite sheet; the solid solution treatment of the shaped sample in step S3 facilitates the alloy elements at the grain boundaries to enter the matrix, realizes solid solution strengthening, and facilitates the subsequent improvement of the stiffness of the aluminum-based composite sheet; the quenching treatment and natural aging treatment further realize the strengthening of the stiffness of the aluminum-based composite material; the rolling treatment of the aluminum-based composite material in step S4 facilitates the thinning of the aluminum-based composite sheet and obtains an aluminum-based composite sheet with a thickness of 0.5-1mm, which meets the requirement of light weight. DETAILED DESCRIPTION

[0022] The technical scheme of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0023] Example 1:

[0024] A preparation method of an aluminum-based composite plate, comprising:

[0025] In step S1, the aluminum alloy powder is mixed with the reinforced particles after surface etching treatment, and then a binder (specifically polyacrylic acid with a molecular weight of 5000-10000) is added, and a solid powder is obtained after mixing;

[0026] The aluminum alloy powder comprises the following raw material components by mass percentage: manganese 0.8%, copper 0.3%, magnesium 0.8%, zinc 0.5%, chromium 0.35%, and the balance of aluminum;

[0027] The reinforced particles are TiCN;

[0028] In step S2, the solid powder is first pressed into a billet, and then the billet is sintered and then molded to obtain a shaped sample;

[0029] In step S3, the shaped sample is sequentially subjected to solid solution treatment and quenching treatment, and then natural aging treatment is performed to obtain an aluminum-based composite material;

[0030] In step S4, the aluminum-based composite material is subjected to rolling treatment to obtain an aluminum-based composite plate with a thickness of 1mm.

[0031] In step S1, the surface etching treatment comprises adding a weak acid to the ammonium bifluoride solution, immersing the reinforced particles in the ammonium bifluoride solution, and then mixing to etch the surface of the reinforced particles for 30s; and the surface-etched reinforced particles are washed and dried.

[0032] The concentration of the ammonium bifluoride solution is 0.5mol / L; the weak acid is phosphoric acid; the concentration of the phosphoric acid is 0.2mol / L; the particle size range of the reinforced particles before surface etching treatment is 500-1000nm, and the use of reinforced particles with this particle size range can better composite the aluminum alloy powder, and the strengthening effect is better, and stress concentration will not occur due to too large particles.

[0033] In the solid powder, the aluminum alloy powder is 97.5% by mass percentage, the reinforced particles are 2%, and the binder is 0.5%.

[0034] In step S2, the pressure used during pressing is 20MPa; the sintering temperature used for sintering treatment is 600℃, and the sintering time is 120min; and the mold shaping uses a mold pressing temperature of 500℃.

[0035] In step S3, the solution treatment uses a solution temperature of 520℃ and a solution time of 10h; the quenching treatment uses heat-conducting oil as the quenching medium, a quenching temperature of 25℃, and a quenching time of 30s; the natural aging treatment involves placing the shaped sample at room temperature for more than 72h.

[0036] In step S4, the rolling process employs multi-pass rolling, and the deformation of each pass is no higher than 1 mm; the rolling temperature used in the rolling process is 400℃.

[0037] Example 2:

[0038] Unlike Example 1, the aluminum alloy powder comprises the following raw materials in weight percentages: 0.6% manganese, 0.2% copper, 0.6% magnesium, 0.4% zinc, 0.25% chromium, and the balance aluminum.

[0039] In the solid powder, by mass percentage, the aluminum alloy powder is 96%, the reinforcing particles are 3%, and the binder is 1%.

[0040] The sintering process was carried out at a temperature of 580℃ for 90 minutes.

[0041] The solution treatment was performed at a temperature of 500°C for 6 hours.

[0042] The thickness of the aluminum-based composite sheet is 0.8mm.

[0043] Example 3:

[0044] Unlike Example 1, the aluminum alloy powder comprises the following raw materials in weight percentages: 0.2% manganese, 0.1% copper, 0.3% magnesium, 0.2% zinc, 0.15% chromium, and the balance aluminum.

[0045] In the solid powder, by mass percentage, the aluminum alloy powder accounts for 93.5%, the reinforcing particles account for 5%, and the binder accounts for 1.5%.

[0046] The sintering process was carried out at a temperature of 550°C for 60 minutes.

[0047] The solution treatment was performed at a temperature of 480°C for 2 hours.

[0048] The thickness of the aluminum-based composite sheet is 0.5mm.

[0049] Comparative Example 1:

[0050] Unlike Example 1, the surface etching process is omitted, and reinforcing particles are added directly.

[0051] Comparative Example 2:

[0052] Different from Example 1, the amount of reinforcing particles is zero.

[0053] Comparative Example 3:

[0054] Different from Example 1, the sintering temperature of the sintering treatment is 500℃.

[0055] Comparative Example 4:

[0056] Different from Example 1, the sintering temperature of the sintering treatment is 650℃.

[0057] Comparative Example 5:

[0058] Different from Example 1, the solid solution temperature of the solid solution treatment is 450℃.

[0059] Comparative Example 6:

[0060] Different from Example 1, the solid solution temperature of the solid solution treatment is 550℃.

[0061] The aluminum matrix composite sheets prepared in Examples 1-3 and Comparative Examples 1-6 are sampled respectively for elastic modulus test, thermal conductivity test and thermal expansion coefficient test. The test results are shown in Table 1. The elastic modulus test method adopts the test standard of GB / T 22315-2008: static tension test is adopted to determine the deformation and stress of the material, and the elastic modulus is calculated according to the relationship between stress and strain according to Hooke's law. The thermal conductivity test method adopts the standard of American Society for Testing and Materials ASTM C518, and the test equipment is YBF-3 tester. The tensile strength test method adopts GBT228.1-2010, Metal Materials Tensile Test Part 1: Room Temperature Test Method.

[0062] Table 1 Performance data of aluminum matrix composite sheets

[0063]

[0064]

[0065] From the data in Table 1, compared with Comparative Examples 1-6, the aluminum matrix composite sheets with high thermal conductivity, high stiffness (represented by elastic modulus) and high strength can be prepared by using Examples 1-3.

[0066] Specifically, by adding the reinforcing particles, the effect of the particle reinforced aluminum matrix composite material can be achieved, and the more the reinforcing particles are added, the more obvious the reinforcing effect is; therefore, the aluminum matrix composite plate prepared in Example 3 has the highest strength and rigidity due to the largest amount of reinforcing particles added; the aluminum matrix composite plate prepared in Comparative Example 2 has the lowest strength and rigidity due to no reinforcing particles added; the aluminum matrix composite plate prepared in Comparative Example 1 has lower strength and rigidity due to the reinforcing particles not being subjected to the surface etching treatment, which makes the reinforcing particles not firmly combined with the aluminum alloy powder, so that the aluminum matrix composite plate prepared has lower strength and rigidity.

[0067] In addition, the aluminum metal in the aluminum alloy powder used in Examples 1-3 of the present application reduces the titanium in the reinforcing particles to form titanium metal, and the titanium metal has alloy strengthening effect on the aluminum alloy matrix, which is also beneficial to improve the strength and rigidity of the aluminum matrix composite plate.

[0068] Compared with Comparative Examples 3-6, the present application can prepare the aluminum matrix composite plate with high thermal conductivity, high rigidity and high strength by controlling the appropriate sintering temperature and solid solution temperature in Examples 1-3.

[0069] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing an aluminum-based composite sheet, characterized in that, include: Step S1: First, mix the aluminum alloy powder with the surface-etched reinforcing particles, then add the binder and mix well to obtain a solid powder. The aluminum alloy powder comprises the following raw materials in weight percentages: manganese 0.2%-0.8%, copper 0.1%-0.3%, magnesium 0.3%-0.8%, zinc 0.2%-0.5%, chromium 0.15%-0.35%, and the balance aluminum; The reinforcing particles include at least one of TiN and TiCN; Step S2: First, the solid powder is pressed into a blank, and then the blank is sintered and molded to obtain a shaped sample. Step S3: After the shaped sample is subjected to solution treatment and quenching treatment in sequence, it is then subjected to natural aging treatment to obtain aluminum-based composite material; Step S4: Roll the aluminum-based composite material to obtain an aluminum-based composite plate with a thickness of 0.5-1mm; In the solid powder, by mass percentage, the aluminum alloy powder accounts for 93.5%-97.5%, the reinforcing particles account for 2%-5%, and the binder accounts for 0.5%-1.5%; In step S3, the solution treatment uses a solution temperature of 480-520℃ and a solution time of 2-10h; the quenching treatment uses heat-conducting oil as the quenching medium, a quenching temperature of 25-45℃, and a quenching time of 30-60s; the natural aging treatment involves placing the shaped sample at room temperature for more than 72h. In step S4, the rolling process employs multi-pass rolling, and the deformation of each pass is no more than 1 mm; the rolling temperature used in the rolling process is 400-450℃.

2. The method for preparing the aluminum-based composite plate according to claim 1, characterized in that, In step S1, the surface etching process includes adding a weak acid to the ammonium bifluoride solution, immersing the reinforcing particles in the ammonium bifluoride solution, mixing them, and then etching the surface of the reinforcing particles for 20-50 seconds. The reinforcing particles after surface etching are cleaned and dried.

3. The method for preparing the aluminum-based composite plate according to claim 2, characterized in that, The concentration of the ammonium bifluoride solution is 0.2-0.5 mol / L; the weak acid includes phosphoric acid; the concentration of the phosphoric acid is 0.1-0.2 mol / L.

4. The method for preparing the aluminum-based composite plate according to claim 1, characterized in that, The particle size of the reinforcing particles before the surface etching process is in the range of 500-1000 nm.

5. The method for preparing the aluminum-based composite plate according to claim 1, characterized in that, In step S2, the pressure used during pressing is 20-100 MPa; the sintering temperature used in the sintering treatment is 550-600℃, and the sintering time is 60-120 min; the molding temperature used in the molding and shaping is 450-500℃.

6. An aluminum-based composite sheet, characterized in that, The aluminum-based composite sheet was prepared using the preparation method described in any one of claims 1-5.

7. An application of an aluminum-based composite panel, characterized in that, The application of the aluminum-based composite plate as described in claim 6 in the manufacture of heat exchangers.

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