Die casting process for aluminum-magnesium alloy vehicle body covering part

Abstract

The invention discloses an aluminum magnesium alloy vehicle body covering part die-casting process which comprises the following steps: S1, taking simple substance aluminum and simple substance magnesium according to a certain proportion, and melting and mixing at 900 DEG C under the protection of inert gas; s2, a rare earth metal regulator is added into the aluminum-magnesium alloy mixed solution, high-temperature melt mixing is carried out under protection of inert gas, and melt mixing is carried out at the temperature of 1400 DEG C; s3, molten mixed metal is injected into a die-casting die in a liquid state through a casting machine for die-casting forming; s4, the mold is placed in a cooling pond to be naturally cooled and solidified; the aluminum-magnesium alloy vehicle body covering part produced through the die-casting process has the advantages of being high in strength and hardness, good in toughness and creep resistance, low in cost, easy and convenient to produce through the die-casting process and the like.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle body manufacturing, and in particular to a die-casting process for an aluminum-magnesium alloy vehicle body covering part. Background Art

[0002] Automobile covering parts refer to the spatially shaped surface or internal parts made of thin metal plates that cover the engine, chassis, cab, and body. According to function and location, they can be divided into three categories: external covering parts, internal covering parts, and frame covering parts. Current body covering parts generally adopt sheet metal structure, and the material is mostly thick and heavy steel plate, which is very heavy and does not meet the current design requirements of lightweight body. Therefore, some covering parts products use aluminum materials to partially reduce the overall weight of the body, but the connection process between aluminum covering parts and steel covering parts is complicated and not integrally formed, resulting in low strength of the overall body covering parts, high cost, and complex production process. In addition, the use of conventional aluminum-magnesium alloy materials still has problems such as low strength, low hardness, poor toughness and creep resistance, and high production cost. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the existing defects and provide a die-casting process for an aluminum-magnesium alloy body covering part. The aluminum-magnesium alloy body covering part has high strength, high hardness, good toughness and creep resistance, low cost, and is easy to produce. The aluminum-magnesium alloy body covering part has good die-casting molding effect and is easy to demold; the problems in the background technology can be effectively solved.

[0004] To achieve the above object, the present invention provides the following technical solution: a die-casting process for an aluminum-magnesium alloy vehicle body panel, comprising the following steps:

[0005] S1. Take elemental aluminum and elemental magnesium, melt and mix them at 900° C. under the protection of inert gas, and the mass ratio of elemental aluminum to elemental magnesium is 6:1-4:1 to obtain a uniform aluminum-magnesium alloy mixture;

[0006] S2. Adding a rare earth metal regulator to the aluminum-magnesium alloy mixture, performing high-temperature melting and mixing under the protection of an inert gas, wherein the melting and mixing temperature is 1400° C. and the melting and mixing time is 1-2 hours;

[0007] S3, injecting S2 aluminum-magnesium molten mixed metal into a die-casting mold in liquid form through a casting machine for die-casting;

[0008] S4. The mold is placed in a cooling pool for natural cooling and solidification. After the aluminum-magnesium alloy casting is cooled and solidified, it is taken out of the mold, and the burrs of the aluminum-magnesium alloy casting are removed.

[0009] Furthermore, the rare earth metal regulator is one or more of lanthanum, cerium, and gadolinium.

[0010] Furthermore, the die-casting mold described in step S3 includes a fixed mold and a movable mold, and the movable mold is located above the fixed mold; a cavity is provided on the upper surface of the fixed mold and the lower surface of the movable mold, and a hydrophobic dot matrix is ​​provided on the surface of the cavity; a casting nozzle and a filter connected to its cavity are provided on the side wall of the fixed mold; a cooling chamber is provided in the movable mold, and a cooling water inlet and a cooling water outlet connected to its cooling chamber are provided on the side wall of the movable mold; the upper surface of the movable mold is connected to a support shell through a plurality of elastic components, a plurality of linear slide rails are vertically provided on the outer side wall of the movable mold, and the support shell is slidably connected to the linear slide rails through sliders.

[0011] Furthermore, the elastic component is an air spring.

[0012] Furthermore, the movable mold and the fixed mold are both provided with limiting holes, and the limiting holes on the movable mold and the fixed mold correspond to each other.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: the die-casting process for aluminum-magnesium alloy body panels is achieved by adding a trace amount of rare earth metal regulators to form a smelting regulator, which is added to an aluminum-magnesium alloy solution and smelted and mixed under an inert gas protective atmosphere to obtain an aluminum-magnesium alloy with uniform composition after smelting. The strength, hardness, toughness and creep resistance of the aluminum-magnesium alloy body panels are improved by rare earth metal elements, thereby making the heat treatment processing of aluminum-magnesium alloy products simpler. By adopting the die-casting process for aluminum-magnesium alloy body panels, the aluminum-magnesium alloy body panels have high strength, high hardness, good toughness and creep resistance, low cost, and the die-casting process for aluminum-magnesium alloy body panels is simple to produce; the die-casting molding effect of the aluminum-magnesium alloy body panels is good and demolding is convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a process flow chart of die-casting of aluminum-magnesium alloy vehicle body panels of the present invention;

[0015] Figure 2 It is a schematic diagram of the structure of the die-casting mold for the aluminum-magnesium alloy body panel of the present invention.

[0016] In the figure: 1. fixed mold; 11. casting nozzle; 12. hydrophobic dot matrix; 13. limiting hole; 2. movable mold; 21. cooling water inlet; 22. cooling water outlet; 3. supporting shell; 4. suction filter; 5. linear guide rail; 6. elastic component. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 are within the scope of protection of the present invention.

[0018] Embodiment 1

[0019] The present invention provides a technical solution: a die-casting process for an aluminum-magnesium alloy vehicle body cover, comprising the following steps:

[0020] S1. Take elemental aluminum and elemental magnesium, melt and mix them at 900° C. under the protection of inert gas, and the mass ratio of elemental aluminum to elemental magnesium is 6:1 to obtain a uniform aluminum-magnesium alloy mixture;

[0021] S2. Adding a rare earth metal regulator to the aluminum-magnesium alloy mixture, and performing high-temperature melt mixing under the protection of an inert gas, wherein the melt mixing temperature is 1400° C. and the melt mixing time is 1 hour; the rare earth metal regulator is one or more of lanthanum, cerium, and gadolinium;

[0022] S3, injecting S2 aluminum-magnesium molten mixed metal into a die-casting mold in liquid form through a casting machine for die-casting;

[0023] S4. The mold is placed in a cooling pool for natural cooling and solidification. After the aluminum-magnesium alloy casting is cooled and solidified, it is taken out of the mold, and the burrs of the aluminum-magnesium alloy casting are removed.

[0024] In this embodiment, a smelting regulator is formed by adding a trace amount of rare earth metal regulator to the mixture. The regulator is added to the aluminum-magnesium alloy solution and smelted and mixed under an inert gas protective atmosphere to obtain an aluminum-magnesium alloy with uniform composition after smelting. The strength, hardness, toughness and creep resistance of the aluminum-magnesium alloy body cover are improved by rare earth metal elements, thereby making the heat treatment processing of the aluminum-magnesium alloy product simpler. By adopting the die-casting process for the aluminum-magnesium alloy body cover, the aluminum-magnesium alloy body cover has high strength, high hardness, good toughness and creep resistance, low cost, and the die-casting process for the aluminum-magnesium alloy body cover is simple to produce.

[0025] Embodiment 2

[0026] The present invention also provides a technical solution: a die-casting process for an aluminum-magnesium alloy vehicle body cover, comprising the following steps:

[0027] S1. Take elemental aluminum and elemental magnesium, melt and mix them at 900° C. under the protection of inert gas, and the mass ratio of elemental aluminum to elemental magnesium is 5:1 to obtain a uniform aluminum-magnesium alloy mixture;

[0028] S2. Adding a rare earth metal regulator to the aluminum-magnesium alloy mixture, and performing high-temperature melt mixing under the protection of an inert gas, wherein the melt mixing temperature is 1400° C., and the melt mixing time is 1.5 h; the rare earth metal regulator is one or more of lanthanum, cerium, and gadolinium;

[0029] S3, injecting S2 aluminum-magnesium molten mixed metal into a die-casting mold in liquid form through a casting machine for die-casting;

[0030] S4. The mold is placed in a cooling pool for natural cooling and solidification. After the aluminum-magnesium alloy casting is cooled and solidified, it is taken out of the mold, and the burrs of the aluminum-magnesium alloy casting are removed.

[0031] Embodiment 3

[0032] The present invention also provides a technical solution: a die-casting process for an aluminum-magnesium alloy vehicle body cover, comprising the following steps:

[0033] S1. Take elemental aluminum and elemental magnesium, melt and mix them at 900° C. under the protection of inert gas, and the mass ratio of elemental aluminum to elemental magnesium is 4:1 to obtain a uniform aluminum-magnesium alloy mixture;

[0034] S2. Adding a rare earth metal regulator to the aluminum-magnesium alloy mixture, performing high-temperature melt mixing under the protection of an inert gas, wherein the melt mixing temperature is 1400° C. and the melt mixing time is 2 hours; the rare earth metal regulator is one or more of lanthanum, cerium, and gadolinium;

[0035] S3, injecting S2 aluminum-magnesium molten mixed metal into a die-casting mold in liquid form through a casting machine for die-casting;

[0036] S4. The mold is placed in a cooling pool for natural cooling and solidification. After the aluminum-magnesium alloy casting is cooled and solidified, it is taken out of the mold, and the burrs of the aluminum-magnesium alloy casting are removed.

[0037] Conventional die-casting process for aluminum-magnesium alloy body panels:

[0038] S1. Take elemental aluminum and elemental magnesium, melt and mix them at 900° C. under the protection of inert gas, and the mass ratio of elemental aluminum to elemental magnesium is 4:1 to obtain a uniform aluminum-magnesium alloy mixture;

[0039] S2. Under the protection of inert gas, the molten mixed metal solution is naturally cooled to room temperature to obtain a homogeneous aluminum-magnesium alloy;

[0040] S3, heating the aluminum-magnesium alloy billet to a molten liquid state by a casting machine, and injecting the liquid aluminum-magnesium alloy into a die-casting mold by the casting machine for die-casting;

[0041] S4. The mold is placed in a cooling pool for natural cooling and solidification. After the aluminum-magnesium alloy casting is cooled and solidified, it is taken out of the mold, and the burrs of the aluminum-magnesium alloy casting are removed.

[0042] The performance comparison of the aluminum-magnesium alloy body panels produced by conventional aluminum-magnesium alloy body panel die-casting process and the aluminum-magnesium alloy body panels produced by die-casting process in Example 1, Example 2 and Example 3 is shown in Table 1:

[0043] Table 1

[0044]

[0045] It can be seen from Table 1 that:

[0046] The aluminum-magnesium alloy body covering parts produced by the aluminum-magnesium alloy body covering parts die-casting process of the present invention have higher hardness, higher tensile strength and better mechanical properties than the aluminum-magnesium alloy body covering parts produced by the conventional aluminum-magnesium alloy body covering parts die-casting process.

[0047] Embodiment 4

[0048] See also Figure 2 The present invention also provides a technical solution: a die-casting mold for an aluminum-magnesium alloy body cover, comprising a fixed mold 1 and a movable mold 2, wherein the movable mold 2 is located above the fixed mold 1; a cavity is provided on the upper surface of the fixed mold 1 and the lower surface of the movable mold 2, and a hydrophobic lattice 12 is provided on the surface of the cavity, and the structure of the hydrophobic lattice 12 is similar to the microporous structure of the surface of a lotus leaf; a casting nozzle 11 and a suction filter 4 connected to the cavity are provided on the side wall of the fixed mold 1; a cooling chamber is provided in the movable mold 2, and a cooling water inlet 21 and a cooling water outlet 22 connected to the cooling chamber are provided on the side wall of the movable mold 2; the upper surface of the movable mold 2 is connected to a support shell 3 through a plurality of elastic components 6, and the elastic components 6 are air springs; a plurality of linear slide rails 5 are vertically provided on the outer side wall of the movable mold 2, and the support shell 3 is slidably connected to the linear slide rails 5 through a slider, and a limiting hole 13 is provided on both the movable mold 2 and the fixed mold 1, and the limiting holes 13 on the movable mold 2 and the fixed mold 1 correspond to each other.

[0049] When the die-casting mold for aluminum-magnesium alloy body panels is in use: the support shell 3 is lowered by an external hydraulic lifting mechanism, the cavity on the lower surface of the movable mold 2 is engaged with the cavity on the upper surface of the fixed mold 1, and the elastic force applied to the movable mold 2 by the elastic component 6 makes it fit tightly with the fixed mold 1, and bolts are passed through the corresponding limiting holes 13 on the fixed mold 1 and the movable mold 2 to align and press them tightly, and the cavity of the movable mold 2 and the cavity of the fixed mold 1 form a molding space structure for the body panel product; the external casting machine injects the molten raw material of liquid aluminum-magnesium alloy into the mold of the fixed mold 1 through the casting nozzle 11 In the cavity, negative pressure is generated in the molding space of the body cover product through the suction filter 4, so that the liquid aluminum-magnesium alloy molten raw material quickly fills the entire body cover product molding space, and at the same time, the bubbles contained in the liquid aluminum-magnesium alloy molten raw material are extracted; it is connected to the external circulating water cooling device through the cooling water inlet 21 and the cooling water outlet 22, and cooling water circulates in the cooling chamber in the movable mold 2, so that the aluminum-magnesium alloy molten liquid is cooled and solidified during the die-casting process; the hydrophobic lattice 12 makes the surface of the molding space of the body cover product have a certain hydrophobicity, which is convenient for demolding.

[0050] The aluminum-magnesium alloy body panel die-casting mold disclosed in the present embodiment uses an elastic component 6 to cooperate with a linear slide rail 5 to make the movable mold 2 vertically descend to pre-tighten the fixed mold 1, and then aligns and presses the fixed mold 1 and the movable mold 2 through bolts and limit holes 13, and the precision of the body panel product molding space structure is high; a negative pressure is generated in the body panel product molding space through a suction filter 4, so that the liquid aluminum-magnesium alloy molten raw material quickly fills the entire body panel product molding space, and at the same time, the bubbles contained in the liquid aluminum-magnesium alloy molten raw material are extracted; the hydrophobic lattice 12 is used to make the surface of the body panel product molding space have a certain hydrophobicity, which is convenient for demolding; the aluminum-magnesium alloy body panel die-casting mold has a simple structure, is easy to operate, has a good die-casting molding effect, and is easy to demold.

[0051] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art 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 appended claims and their equivalents.

Claims

1. A die-casting process for aluminum-magnesium alloy body panels, characterized in that: The following steps are involved: S1. Take elemental aluminum and elemental magnesium, melt and mix them at 900° C. under the protection of inert gas, and the mass ratio of elemental aluminum to elemental magnesium is 6:1-4:1 to obtain a uniform aluminum-magnesium alloy mixture; S2. Adding a rare earth metal regulator to the aluminum-magnesium alloy mixture, performing high-temperature melting and mixing under the protection of an inert gas, wherein the melting and mixing temperature is 1400° C. and the melting and mixing time is 1-2 hours; S3, injecting S2 aluminum-magnesium molten mixed metal into a die-casting mold in liquid form through a casting machine for die-casting; S4. The mold is placed in a cooling pool for natural cooling and solidification. After the aluminum-magnesium alloy casting is cooled and solidified, it is taken out of the mold, and the burrs of the aluminum-magnesium alloy casting are removed.

2. The die-casting process of aluminum-magnesium alloy vehicle body panels according to claim 1, characterized in that: The rare earth metal modifier is one or more of lanthanum, cerium and gadolinium.

3. The die-casting process of aluminum-magnesium alloy vehicle body panels according to claim 1, characterized in that: The die-casting mold described in step S3 includes a fixed mold and a movable mold, and the movable mold is located above the fixed mold; a cavity is provided on the upper surface of the fixed mold and the lower surface of the movable mold, and a hydrophobic dot matrix is ​​provided on the surface of the cavity; a casting nozzle and a suction filter connected to its cavity are provided on the side wall of the fixed mold; a cooling chamber is provided in the movable mold, and a cooling water inlet and a cooling water outlet connected to its cooling chamber are provided on the side wall of the movable mold; the upper surface of the movable mold is connected to a support shell through a plurality of elastic components, a plurality of linear slide rails are vertically provided on the outer side wall of the movable mold, and the support shell is slidably connected to the linear slide rails through sliders.

4. The die-casting process of aluminum-magnesium alloy body panels according to claim 3, characterized in that: The elastic component is an air spring.

5. The die-casting process of aluminum-magnesium alloy vehicle body panels according to claim 3, characterized in that: The movable mold and the fixed mold are both provided with limiting holes, and the limiting holes on the movable mold and the fixed mold correspond to each other.

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