Foamed aluminum and vehicle thereof

Abstract

The utility model discloses foamed aluminum and a vehicle thereof, the foamed aluminum comprises a body, the body comprises a first part and a second part, the first part and the second part are sequentially arranged along a first direction, the first part has a first porosity P1, the second part has a second porosity P2, P1 is more than or equal to 20% and less than 90%, P2 is more than 20% and less than or equal to 90%, and P1 is less than P2; the first part is provided with a transition layer close to the second part, and the porosity of the transition layer is smaller than the first porosity. According to the foamed aluminum, the weight can be reduced, reinforcement and energy absorption can be achieved, and the manufacturing cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of porous metal lightweight structures, in particular to foam aluminum and a vehicle thereof. Background Art

[0002] In the related art, most foamed aluminum is uniform foamed aluminum, and the process strives to achieve uniform foaming and the same porosity at all locations. For example, when foamed aluminum is used to make an anti-collision beam, the porosity at all locations in the width direction of the anti-collision beam is the same. The production cost of foamed aluminum in the prior art is high and the weight is high. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the utility model is to propose a foam aluminum, the porosity of the first part is lower than the porosity of the second part, the second part can be used as a soft zone structure, and can protect parts in daily low-speed collisions; the first part can be used as a hard zone structure, and in the rear collision process, after the soft zone structure is completely collapsed, it can provide certain support to maintain the stability of the rear structure and continue to participate in energy absorption. Through the cooperation of the first part and the second part, not only can energy be absorbed, but also weight can be reduced and cost can be reduced.

[0004] Another object of the utility model is to provide a vehicle using the foam aluminum.

[0005] The foam aluminum according to the embodiment of the first aspect of the utility model includes: a main body, the main body includes a first part and a second part, the first part and the second part are arranged in sequence along a first direction, the first part has a first porosity P1, the second part has a second porosity P2, 20%≤P1<90%, 20%<P2≤90%, and P1<P2; wherein, the first part has a transition layer near the second part, and the porosity of the transition layer is less than the first porosity.

[0006] According to the foam aluminum of the embodiment of the utility model, the body includes a first part and a second part with different porosities, and the first part and the second part are connected by a transition layer. The first part with low porosity can be prepared first, and the second part with high porosity can be prepared after removing the baffle, which is conducive to reducing costs. The foam aluminum according to the utility model can not only reduce weight, but also achieve reinforcement and energy absorption, and has low production cost.

[0007] According to some embodiments of the present invention, the porosity of the first part is 30%-50%, and / or the porosity of the second part is 60%-80%.

[0008] According to some embodiments of the present invention, the volume ratio of the first part to the second part is 3:2-4:1.

[0009] According to some embodiments of the present invention, in the first direction, the thickness of the transition layer is 0.1-0.3 of the thickness of the first part.

[0010] According to some embodiments of the present invention, the first direction is the width direction of the body, and along the first direction, the lengths of the first part and the second part are 190 mm-210 mm respectively, and the length of the transition layer is 20 mm-50 mm.

[0011] According to some embodiments of the present invention, the main body is an arc-shaped member, and in a first direction, the first portion is closer to the arc center of the arc-shaped member than the second portion.

[0012] According to some embodiments of the present invention, the transition layer (3) is a straight line region or an arc-shaped region extending along a second direction, and the second direction is arranged non-parallel to the first direction.

[0013] According to some embodiments of the present invention, the foam aluminum is foam aluminum with precipitated strengthening phase Mg2Si.

[0014] According to some embodiments of the present invention, the body is a one-piece piece.

[0015] The vehicle according to the second embodiment of the utility model comprises the foamed aluminum according to the first embodiment of the utility model.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0018] Figure 1 is a schematic diagram of a molten pool according to an embodiment of the utility model;

[0019] Figure 2 This is a schematic diagram of the connection between the foam aluminum and the left longitudinal beam and the right longitudinal beam of the rear floor according to an embodiment of the utility model;

[0020] Figure 3 It is a cross-sectional view of foamed aluminum according to an embodiment of the utility model.

[0021] Reference numerals:

[0022] 100: Ontology;

[0023] 1: first part; 2: second part; 3: transition layer;

[0024] 201: baffle; 202: molten pool 1; 203: molten pool 2;

[0025] 301: 6082 aluminum molten liquid;

[0026] 401: left longitudinal beam of rear floor; 402: right longitudinal beam of rear floor. DETAILED DESCRIPTION

[0027] Reference below Figures 1 to 3 The foamed aluminum according to the first embodiment of the utility model is described. It should be noted that the utility model is described by taking the foamed aluminum applied to the rear anti-collision beam of the vehicle as an example, but it is not limited thereto.

[0028] like Figure 2 and Figure 3 As shown, the foam aluminum according to the embodiment of the first aspect of the utility model includes a main body 100.

[0029] Specifically, the body 100 includes a first part 1 and a second part 2, the first part 1 and the second part 2 are arranged in sequence along a first direction, the first part 1 has a first porosity P1, the second part 2 has a second porosity P2, 20%≤P1<90%, 20%<P2≤90%, and P1<P2. The first part 1 has a transition layer 3 near the second part 2, and the porosity of the transition layer 3 is less than the first porosity.

[0030] In other words, the foamed aluminum of the present invention is mainly composed of a body 100, which includes a first part 1 and a second part 2, wherein the porosity of the first part 1 is less than that of the second part 2, and the first porosity and the second porosity are both 20%-90%. For example, the first porosity is 20%, 25%, 30%, 35%, 40% or 50%, etc., and the second porosity is 21%, 25%, 28%, 30%, 35%, 41%, 50%, 55%, 60%, 70%, 75%, 80% or 90%, etc. Among them, the first part 1 can be defined as a low-porosity part, and the second part 2 can be defined as a high-porosity part.

[0031] The first part 1 and the second part 2 are sequentially arranged along a first direction. For example, the first direction is a front-to-back direction, and the first part 1 and the second part 2 are sequentially distributed along the front-to-back direction.

[0032] In this embodiment, the first part 1 has a transition layer 3 near the second part 2, and the porosity of the transition layer 3 is lower than the porosity of the first part 1. It should be noted that when preparing foamed aluminum, the molten pool can be divided into a molten pool 1 202 and a molten pool 2 203 by a baffle 201, such as a steel baffle, and then the first part 1 with low porosity is first prepared in the molten pool 1 202. Under the action of the baffle 201, at least a part of the transition layer 3 is formed at the position of the first part 1 near the baffle 201; then the baffle 201 can be removed, and the second part 2 with high porosity is prepared in the molten pool 2 203, which is convenient to manufacture and can effectively reduce the cost of manufacturing foamed aluminum with different porosities.

[0033] In addition, the first part 1 and the second part 2 are arranged in sequence along the first direction, and the collision force from the first direction can be first transmitted to the second part 2, and then transmitted to the first part 1 through the second part 2. For example, the body 100 is subjected to the following Figure 2 The force F shown. That is, when the first part 1 and the second part 2 simultaneously receive the collision force from the first direction, the collision force can be absorbed by the second part 2 first and then by the first part 1, that is, the collision force from the first direction is first transmitted to the second part 2 and then transmitted to the first part 1 through the second part 2.

[0034] It can be seen that in this embodiment, the body 100 includes a first part 1 and a second part 2. The porosity of the first part 1 is lower than that of the second part 2. The second part 2 can be used as a soft zone structure to protect parts in daily low-speed collisions. For example, the foamed aluminum is used for the rear anti-collision beam to protect the internal structure of the rear bumper. If the internal structure of the rear bumper is invaded by the foamed aluminum, it will not be damaged and can continue to be used. At the same time, the rear anti-collision beam made of foamed aluminum will not be damaged and can continue to be used. It can be seen that the foamed aluminum of the utility model can be applied to the current environment where accidents are frequent and has strong practicality.

[0035] Moreover, the first part 1 can be used as a hard zone structure. During the rear collision process, after the soft zone structure is completely collapsed, it can provide certain support, maintain the stability of the rear structure, and continue to participate in energy absorption. It can be seen that when the foam aluminum of the embodiment of the utility model is used as a rear anti-collision beam, the damage to the components of the rear structure of the vehicle can be reduced in a low-speed collision scenario by setting a sequence of collapse energy absorption. At the same time, it can buffer energy absorption as much as possible in a high-speed collision scenario to improve the safety performance of the vehicle. In addition, by matching the first part 1 and the second part 2 with different porosities, the overall weight of the body 100 can also be reduced.

[0036] Therefore, according to the foam aluminum of the embodiment of the utility model, the body 100 includes a first part 1 and a second part 2 with different porosities, and the first part 1 and the second part 2 are connected by a transition layer 3. The first part 1 with low porosity can be prepared first, and the second part 2 with high porosity can be prepared after removing the baffle 201. The foam aluminum with different porosities can be prepared in a simple way, which is conducive to reducing costs. The foam aluminum according to the utility model can not only reduce weight, but also achieve reinforcement and energy absorption, and has low production cost.

[0037] According to an embodiment of the utility model, the porosity of the first part 1 is 30%-50%, and / or the porosity of the second part 2 is 60%-80%. For example, the first porosity is 30%, 32%, 35%, 40%, 45% or 50%, etc.; the second porosity is 60%, 62%, 65%, 70%, 75%, 79% or 80%, etc. In this embodiment, the first porosity and the second porosity can have a variety of ranges, and within the above ranges, the first part 1 can not only be used to provide support, but also have a certain collapse energy absorption capacity, and the second part 2 has a stronger collapse energy absorption capacity.

[0038] In some specific embodiments of the present invention, the volume ratio of the first part 1 to the second part 2 is 3:2-4:1, that is, V1:V2=3:2-4:1. For example, the volume ratio of the first part 1 to the second part 2 is 3:2, 2:1, 3:1, 4:1, etc.

[0039] The following description will be made by taking V1:V2=6:4 as an example.

[0040] When the volume ratio of the first part 1 to the second part 2 is 6:4, the first part 1 has a smaller porosity and a stronger structure, and can be regarded as a beam-like component, while the second part 2 has a larger porosity and a weaker structure, and can be regarded as a pedestrian protection foam. The second part 2 is then designed with a bumper shape, which can cover the entire rear end of the rear anti-collision beam and has a certain X-direction thickness (at least 20 mm). It should be noted that the X-direction here can be the front and rear direction of the vehicle.

[0041] In this embodiment, by adopting a volume ratio of 3:2-4:1 between the first part 1 and the second part 2, when the foam aluminum is applied to the anti-collision beam of the vehicle, the second part 2 can ensure sufficient pedestrian protection; and the first part 1 can ensure structural safety of collision.

[0042] According to one embodiment of the utility model, the thickness of the transition layer 3 is 0.1-0.3 of the thickness of the first part 1. For example, the thickness of the transition layer 3 is 0.1, 0.2 or 0.3 of the thickness of the first part 1. It can be seen that the thickness of the transition layer 3 is relatively small, which reduces its influence on the overall energy absorption effect and weight of the foam aluminum.

[0043] In some specific embodiments of the present invention, the first direction is the width direction of the main body 100. Along the first direction, the lengths of the first part 1 and the second part 2 are respectively 190mm-210mm, and the length of the transition layer 3 is 20mm-50mm. It can be seen that the thickness of the transition layer 3 is relatively small, which reduces the influence of the transition layer 3 on the size of the main body 100.

[0044] According to an embodiment of the present invention, the body 100 is an arc-shaped member, and in the first direction, the first portion 1 is closer to the arc center of the arc-shaped member than the second portion 2, which is conducive to achieving that when the body 100 is connected to the vehicle body structure, the collision force can be first absorbed by the second portion 2 and then absorbed by the first portion 1. For example, the first portion 1 is connected to the floor longitudinal beam, and the second portion 2 first absorbs the rear impact force F as shown in Figure 2, and then transmits it to the first portion 1 and is absorbed by the first portion 1.

[0045] According to one embodiment of the utility model, the transition layer 3 is a straight area or an arc-shaped area extending along the second direction, and the second direction is arranged non-parallel to the first direction. It can be seen that the transition zone 3 can be either a straight area or an arc-shaped area. For example, the foam aluminum is a long strip, the first direction is the front-to-back direction, the second direction is the left-to-right direction, and the transition layer 3 is a long strip extending from left to right. It should be noted that when a straight area is used in the transition zone 3, it is beneficial to the process treatment, wherein the partition design in the molding process is a straight line. By using a straight area as the transition zone 3, the thickness of the second part 2 is uniform (the dimension in the X direction), which is beneficial to the energy absorption of low-speed collisions. The thickness of the first part 1 is also uniform at various locations, which is beneficial to the transmission of force during the collision.

[0046] In this embodiment, the use of an arc-shaped transition zone 3 is conducive to achieving design performance priority, and the use of a straight-line transition zone 3 is conducive to achieving process priority.

[0047] Optionally, both ends of the body 100 may be connected to the floor longitudinal beams, for example, Figure 2 As shown, the left front end of the body 100 is connected to the left longitudinal beam 401 of the rear floor, and the right front end of the body 100 is connected to the right longitudinal beam 402 of the rear floor.

[0048] In some specific embodiments of the present invention, the aluminum foam is an aluminum foam with precipitated strengthening phase Mg2Si. For example, in this embodiment, the preparation method of the aluminum foam includes the following steps:

[0049] The matrix is ​​melt-cast to obtain a molten alloy, wherein the molten alloy contains Al and Si elements;

[0050] Magnesium carbonate is added as a foaming agent into the melt of the casting alloy for foaming, and then heat-insulated after foaming to dissolve the strengthening phase Mg2Si;

[0051] Through online quenching and cooling, a solid solution with supersaturated vacancies and solute atoms is obtained, which provides a carrier for the precipitation of the strengthening phase Mg2Si.

[0052] Through artificial aging treatment, foamed aluminum with precipitated strengthening phase Mg2Si is obtained.

[0053] In other words, the method for preparing foamed aluminum according to the embodiment of the utility model comprises the following steps:

[0054] First, a melting and casting process is performed to obtain a melting and casting alloy melt, wherein the melting and casting alloy melt contains Al elements and Si elements.

[0055] Then, magnesium carbonate powder is added to the molten alloy. Magnesium carbonate is used as a foaming agent. Magnesium carbonate decomposes and foams to obtain a strengthening phase, and the main strengthening phase Mg2Si of the alloy is solid-dissolved. In actual operation, magnesium carbonate powder can be put into the melting furnace through a barrel, stirred and foamed to completely dissolve the main strengthening phase Mg2Si of the alloy.

[0056] Subsequently, the temperature is lowered by online quenching to obtain a solid solution with supersaturated vacancies and solute atoms, which provides a carrier for the precipitation of the strengthening phase Mg2Si. For example, the temperature is lowered by online water mist quenching.

[0057] Finally, artificial aging is carried out to obtain foamed aluminum with precipitated strengthening phase Mg2Si.

[0058] It should be noted that, in this embodiment, by adding magnesium carbonate as a foaming agent, the decomposition reaction of magnesium carbonate is as follows:

[0059] MgCO3 → MgO + CO2 (1).

[0060] Among them, the decomposition temperature of magnesium carbonate is 540℃, and magnesium carbonate does not need special pretreatment. When heated and foamed, the decomposition speed of magnesium carbonate is slow, and the stirring time and insulation time can be extended at a lower stirring speed, which is conducive to its homogenization. At the same time, the price of magnesium carbonate is much cheaper than that of TiH2, which reduces the production cost.

[0061] Moreover, in this embodiment, magnesium carbonate is used as a foaming agent, which can save a tackifier, or no tackifier is added. In addition, the heat treatment of conventional foam aluminum requires first making a foam aluminum part, and then performing a solid solution and aging treatment, while in this embodiment, the solid solution is directly performed after foaming, which saves process steps and reduces production energy consumption.

[0062] For example, the preparation method of aluminum foam includes the following steps:

[0063] S1, Melting alloy

[0064] In the melting and casting process, the alloy melt contains Mn and Cr, the Mn content is 0.6%-0.65%, the Cr content is less than 0.15%, and the total content of Mn and Cr is 0.70%-0.80%, which is conducive to the preparation of 6082 aluminum alloy composition. In addition, the melting and casting temperature is 740℃-760℃.

[0065] S2. Add magnesium carbonate powder to foam

[0066] The magnesium carbonate powder is put into the melting furnace through the barrel, stirred, foamed, and kept warm at 740°C. The magnesium carbonate is decomposed to obtain the strengthening phase, and the main strengthening phase Mg2Si is completely dissolved at 740°C.

[0067] S3, online quenching

[0068] The online water mist quenching treatment has high quenching cooling intensity and fast cooling speed, which can quickly reduce the temperature to below 50°C, which is conducive to obtaining a solid solution with supersaturated vacancies and solute atoms, providing a carrier for the precipitation of the strengthening phase.

[0069] S4. Artificial aging

[0070] The aging temperature is 170℃-180℃, the holding time is 6h-8h, and the storage time of the foamed aluminum before aging does not exceed 8h, which is conducive to the decomposition of the supersaturated solid solution and the precipitation of a nano-scale strengthening phase coherent with the matrix. The platform stress of the prepared foamed aluminum is increased by 40% (about 40Mpa) compared with that before heat treatment, and the energy absorption effect is increased by 50%.

[0071] Therefore, in this embodiment, heat treatment is performed during the foam aluminum forming process, specifically, the foam aluminum solution is subjected to solution treatment, online quenching and artificial aging treatment. Through the combined process, not only can energy be saved, but also the energy absorption effect of the product can be improved. For example, the foam aluminum prepared by the traditional melt foaming method is compared with the foam aluminum prepared by the method of this embodiment. The platform stress of the foam aluminum of this embodiment is increased by 40% (about 40Mpa) compared with that before heat treatment, and the energy absorption effect is improved by 50%. Among them, there is a compression stage in the collapse process of the foam aluminum. The foam aluminum continues to collapse, but the stress is almost unchanged. The stress in this stage is called "platform stress".

[0072] Optionally, when magnesium carbonate is added to the molten alloy, the temperature is kept within the range of 700°C-780°C, for example, 700°C, 710°C, 720°C, 730°C, 740°C, 750°C, 760°C, 770°C or 780°C. It is understandable that the decomposition temperature of magnesium carbonate is 540°C. The casting temperature of the molten casting process can be 740°C-760°C. When magnesium carbonate is added and kept at 740°C, the magnesium carbonate will decompose, and not only a strengthening phase can be obtained, but also the strengthening phase can be dissolved in the temperature range of 700°C-780°C. For example, the strengthening phase can be completely dissolved when the temperature is kept at 740°C for a preset time.

[0073] Optionally, keeping warm at 700°C-780°C for 2h-4h, for example, keeping warm for 2h, 2.5h, 4h, 3.5h or 4h, etc., can ensure the solid solution of the strengthening phase. For example, keeping warm at 740°C for 4h can completely dissolve the strengthening phase.

[0074] Optionally, when cooling by online quenching, the temperature is cooled to below 50°C within 1h-2h, which can simultaneously achieve high quenching cooling intensity and fast cooling speed, so that the temperature is quickly reduced to below 50°C, which is conducive to obtaining a solid solution with supersaturated vacancies and solute atoms, providing a carrier for the precipitation of the strengthening phase.

[0075] Optionally, during artificial aging treatment, the aging temperature is 170°C-180°C, the holding time is 6h-8h, and the parking time of the foamed aluminum before aging does not exceed 8h. In this embodiment, by controlling the temperature, holding time and parking time of artificial aging, it is beneficial to achieve the precipitation and decomposition of the supersaturated solid solution and to precipitate a nano-scale strengthening phase that is coherent with the matrix.

[0076] Optionally, the matrix is ​​an aluminum ingot. That is, the traditional foamed aluminum needs aluminum powder as the matrix, and the cost is high, while the present embodiment directly uses aluminum ingots, which can effectively reduce the cost.

[0077] Optionally, the casting alloy melt further contains Mn and Cr, with the Mn content being 0.6%-0.65%, the Cr content being less than 0.15%, and the total content of Mn and Cr being 0.70%-0.80%. That is to say, in the casting process, the content range of Mn and Cr can be controlled. Specifically, by controlling the Mn content to be 0.6%-0.65%, the Cr content to be less than 0.15%, and the total content of Mn and Cr to be 0.70%-0.80%, for example, the Mn content is 0.6%, 0.61%, 0.62%, 0.63%, 0.64% or 0.65%, etc.; the Cr content is 0.15%, 0.14%, 0.13%, 0.12%, 0.11%, 0.10%, 0.09%, 0.08%, 0.07%, 0.06%, 0.05%, 0.04%, 0.03%, 0.02% or 0.01%, etc., and the total content of Mn and Cr is 0.70%, 0.71%, 0.72%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79% or 0.80%, etc., which can not only achieve the composition control of 6082 aluminum alloy, but also have the effect of increasing viscosity.

[0078] According to an embodiment of the present invention, the main body 100 is an integrated component. By adopting an integrated structural component, the structural stability and reliability can be improved.

[0079] Optionally, the method for preparing aluminum foam comprises the following steps:

[0080] Preparing a first portion having a first porosity;

[0081] The first part is placed in a part of the molten pool, and after the first part is solid-dissolved, a molten cast alloy is added to another part of the molten pool and foamed to prepare a second part connected to the first part, the second part having a second porosity greater than the first porosity. For example, the first part 1 is prepared first, and after the low-porosity part of the outer edge of the first part 1 is removed, the first part 1 is placed in the molten pool and the second part 2 is prepared, so that the thickness of the transition layer 3 can be further reduced.

[0082] Optionally, the step of adding magnesium carbonate to the molten cast alloy for foaming comprises:

[0083] like Figure 1 As shown, the molten pool is divided into a first pool and a second pool by a baffle 201;

[0084] Magnesium carbonate is added to the first pool, and a portion of the molten cast alloy is added to the first pool for foaming to obtain a first portion 1 having a first porosity;

[0085] The baffle 201 is removed so that the first pool and the second pool are connected;

[0086] Magnesium carbonate is added to the second pool, and another portion of the cast alloy melt is added to the second pool for foaming to obtain a second portion 2 having a second porosity, the second porosity being greater than the first porosity, that is, the first porosity is a low porosity and the second porosity is a high porosity. The size of the first porosity and the second porosity can be specifically controlled by the ratio of the melt and the foaming agent.

[0087] It can be seen that the preparation method of the foam aluminum in this embodiment is a preparation method of foam aluminum with different porosities. Specifically, a method of first preparing a low-porosity part and then preparing a high-porosity part is adopted. In this embodiment, by first preparing a low-porosity foam aluminum and then preparing a high-porosity foam aluminum, it is possible to avoid gas expansion causing the internal structure of the high-porosity foam aluminum to be damaged. In addition, by using a low-porosity foam aluminum structure, the economic cost of post-maintenance maintenance is greatly reduced and the weight is reduced.

[0088] It should be noted that by adopting the strengthening methods of foam aluminum solid solution, online quenching and artificial aging, and strengthening foam aluminum with different porosities at the same time, the platform stress can be increased and the energy absorption effect can be improved.

[0089] Optionally, after preparing the first part 1 with the first porosity, the molten pool is cooled to 200°C-400°C and then the baffle 201 is removed; after removing the baffle 201, the molten pool is heated to 400°C-700°C, and the foamed aluminum in the first pool is solid-dissolved again. In this embodiment, when the method of first preparing the low-porosity part and then preparing the high-porosity part is adopted, the cooling temperature and the re-solidification temperature are controlled so that the parts are firmly connected and the thickness of the transition layer 3 is small. For example, after preparing the low-porosity part, the molten pool is cooled to 200°C-400°C, and the baffle 201 is removed. For example, the molten pool is cooled to 200°C, 230°C, 250°C, 300°C, 350°C or 400°C, etc. It should be noted that the foamed aluminum is basically formed into a solid state within the range of 200°C-400°C. In addition, after the baffle 201 is removed, the molten pool can be heated to 400°C-700°C, such as 400°C, 450°C, 500°C, 550°C, 600°C, 650°C or 700°C, etc., so that the foamed aluminum in the molten pool is dissolved again. In this embodiment, by temperature difference control, specifically controlling that after preparing the first part 1 with the first porosity, the molten pool is cooled to 200°C-400°C and then the baffle 201 is removed; after the baffle 201 is removed, the molten pool is heated to 400°C-700°C, and the foamed aluminum in the first pool is dissolved again, so that the thickness of the transition layer 3 can be reduced.

[0090] The utility model also provides a vehicle, comprising the foamed aluminum of any of the above embodiments, and optionally, the beam parts of the vehicle are made of foamed aluminum. Since the foamed aluminum of the embodiment of the utility model has the advantages of reducing costs, the vehicle of the embodiment of the utility model also has the advantages of low cost, which will not be elaborated here.

[0091] The foamed aluminum according to the embodiment of the utility model is described in detail below in conjunction with specific embodiments.

[0092] Example 1

[0093] like Figure 1 As shown, in Example 1, the molten pool is divided into a molten pool 1 202 and a molten pool 2 203 arranged along the front-to-back direction by a detachable steel baffle.

[0094] The preparation process of the aluminum foam of Example 1 is as follows:

[0095] S1, Melting alloy

[0096] In the melting and casting process, the melting and casting alloy melt contains Mn and Cr, the Mn content is 0.6%-0.65%, the Cr content is less than 0.15%, and the total content of Mn and Cr is 0.70%-0.80%, which is conducive to the preparation of 6082 aluminum alloy composition. In addition, the melting and casting temperature is 740℃-760℃, and the temperature is kept at 740℃.

[0097] S2. Low porosity preparation

[0098] Magnesium carbonate as a foaming agent is placed in advance in the molten pool 202, and then the 6082 aluminum solution 301 is added to the molten pool 202 and stirred for foaming. The molten pool 202 can be called a low-porosity molten pool.

[0099] S3, cooling and removing baffle 201

[0100] The molten pool is cooled to 300° C., and the baffle 201 is removed.

[0101] S4. Heating the molten pool

[0102] The molten pool 1 202 and the molten pool 2 203 are heated to 500° C., and the foamed aluminum in the molten pool 1 202 is re-solidified.

[0103] S5. High Porosity Preparation

[0104] Put the foaming agent magnesium carbonate in advance in the second molten pool 203, then add the aluminum liquid into the second molten pool 203, stir and foam. To ensure complete foaming, the heating temperature in the second molten pool 203 can be appropriately increased to 550° C. Among them, the second molten pool 203 can be called a high-porosity molten pool.

[0105] S6, overall online quenching

[0106] Water mist quenching treatment is adopted, which has high quenching cooling intensity and fast cooling speed, so that the temperature can be quickly reduced to below 50℃ in 1h-2h.

[0107] S7, artificial aging

[0108] Aging temperature is 170℃-180℃, and the insulation time is 6h-8h.

[0109] It is understandable that if the amount of molten aluminum in the molten pool is relatively small, the baffle 201 can be replaced by a thin steel plate and a supporting leg. After the molten aluminum in the molten pool 1 202 is cooled to 400°C, only the supporting leg can be removed without removing the thin steel plate, and the molten aluminum can be directly added to the molten pool 2 203, thereby reducing energy waste and cooling time in S3.

[0110] like Figure 2 As shown, an arc-shaped anti-collision beam can be prepared by the preparation method of Example 1. The length direction of the arc-shaped part is the left-right direction, and the width direction is the front-to-back direction. Along the front-to-back direction (or the X-axis direction), the rear collision direction is from back to front. The rear end of the anti-collision beam has a porosity of 80%, and the rear end can be used as a soft zone structure, which can protect the internal structure of the rear bumper in daily extremely low-speed collisions. The internal structure of the rear bumper will not be damaged if it invades the foamed aluminum and can continue to be used. At the same time, the foamed aluminum rear anti-collision beam will not be damaged and can continue to be used. The foamed aluminum of this embodiment is very practical in the current environment where accidents are frequent. The front end of the anti-collision beam has a porosity of 40%, and the front end can be used as a hard zone structure. During the rear collision process, after the soft zone structure is completely collapsed, it can provide certain support to maintain the stability of the rear structure and continue to participate in energy absorption.

[0111] In this embodiment, on the one hand, controlling the ratio of the foaming agent to the aluminum liquid is beneficial to controlling the porosity; on the other hand, the method of first preparing the low-porosity part and then preparing the high-porosity part is adopted, so that the parts are firmly connected, and the foam aluminum formed in batches can be fused; on the other hand, through the temperature control in step S3 and step S4, the temperature difference between step S3 and step S4 can be smaller, so that the bubble distribution in the molten pool is more uniform. On the contrary, if the temperature difference is large and the bubble distribution is uneven, the transition layer 3 will be thicker, and the porosity of the transition layer 3 will be difficult to control. In this embodiment, step S3 and step S4 cooperate with each other, which is beneficial to achieving a smaller thickness of the transition layer 3, for example, the transition layer 3 is about 20mm-50mm.

[0112] In summary, according to the foam aluminum of this embodiment, the foam aluminum includes a first part 1 and a second part 2. The porosity of the first part 1 is lower than that of the second part 2. The second part 2 can be used as a soft zone structure to protect parts in daily low-speed collisions. If the parts invade into the foam aluminum, they will not be damaged and can continue to be used. At the same time, the rear anti-collision beam made of foam aluminum will not be damaged and can continue to be used. In addition, the first part 1 can be used as a hard zone structure. During the rear collision, after the soft zone structure is completely collapsed, it can provide certain support, maintain the stability of the rear structure, and continue to participate in energy absorption. The foam aluminum of the embodiment of the utility model can be suitable for the current environment where accidents are frequent, has strong practicality, and can also reduce costs.

[0113] Other structures and operations of the vehicle according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0114] In the description of the present invention, it should be understood that the terms "center", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "inside", "outside", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0115] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0116] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example.

[0117] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A foamed aluminum, characterized in that: include: A body (100), the body (100) comprising a first part (1) and a second part (2), the first part (1) and the second part (2) being arranged in sequence along a first direction, the first part (1) having a first porosity P1, the second part (2) having a second porosity P2, 20%≤P1<90%, 20%<P2≤90%, and P1<P2; The first part (1) has a transition layer (3) at a position close to the second part (2), and the porosity of the transition layer (3) is smaller than the first porosity.

2. The foamed aluminum according to claim 1, characterized in that: The porosity of the first part (1) is 30%-50%, and / or the porosity of the second part (2) is 60%-80%.

3. The foamed aluminum according to claim 1, characterized in that: The volume ratio of the first part (1) to the second part (2) is 3:2-4:

1.

4. The foamed aluminum according to claim 1, characterized in that: In the first direction, the thickness of the transition layer (3) is 0.1-0.3 of the thickness of the first part (1).

5. The foamed aluminum according to claim 4, characterized in that: The first direction is the width direction of the body (100), and along the first direction, the lengths of the first part (1) and the second part (2) are respectively 190 mm-210 mm, and the length of the transition layer (3) is 20 mm-50 mm.

6. The aluminum foam according to claim 1, characterized in that: The body (100) is an arc-shaped member, and in a first direction, the first portion (1) is closer to the arc center of the arc-shaped member than the second portion (2).

7. The foamed aluminum according to claim 6, characterized in that: The transition layer (3) is a straight-line region or an arc-shaped region extending along a second direction, and the second direction is arranged non-parallel to the first direction.

8. The foamed aluminum according to claim 1, characterized in that: The foamed aluminum is foamed aluminum with precipitated strengthening phase Mg2Si.

9. The foamed aluminum according to claim 1, characterized in that: The body (100) is a one-piece piece.

10. A vehicle, characterized in that: The invention comprises the foamed aluminum as described in any one of claims 1 to 9.

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