Aluminum alloy material with refined surface grains and preparation method of aluminum alloy material

Abstract

The aluminum alloy material for refining the surface crystal grains comprises the following components in percentage by mass: 0.3-0.55% of Si, 0.1-0.5% of Al, 0.1-0.5% of Ti, and the balance of Al and inevitable impurities. Fe: 0.05 to 0.36 percent; 0.01 to 0.4 percent of Cu; 0.01 to 0.09 percent of Mn; 0.38 to 0.62 percent of Mg; 0.03 to 0.08% of Zn; ti: 0.01 to 0.04%; cr: 0.01 to 0.04%; 0.01% to 0.04% of V; 0.05% to 0.08% of Na; the impurities are less than or equal to 0.3%; wherein the strengthening phase of the alloy is Mg2Si, the mass ratio of magnesium to silicon is 1.6-1.9, and the content of Mg2Si is 0.8-1.1%.

Description

Technical Field

[0001] The invention relates to the field of aluminum alloys, and in particular to an aluminum alloy material with refined surface grains and a preparation method thereof. Background Art

[0002] Aluminum alloy profiles have many advantages, such as light weight, high strength, good processing ductility and weldability, can meet various surface treatment requirements, and can be recycled and reused repeatedly. It is the most widely used metal material for lightweight materials. However, it is very easy to produce coarse surface grains during the production and manufacturing process of aluminum profiles, resulting in 1. Decreased strength: The larger the grain size, the lower the strength of the aluminum. Aluminum profiles with coarse grains are prone to deformation and cracking when subjected to pressure and load, thus affecting their service life and stability. 2. Reduced toughness: The size of the grain is closely related to the toughness of the aluminum. Aluminum profiles with coarse grains often have poor toughness and are prone to cracks and fractures during use. 3. Rough surface: When processing aluminum profiles, if the grain size is too large, it will lead to poor surface treatment and a rough surface, affecting the appearance and use of the product. Summary of the invention

[0003] In order to solve the above problems, the present invention provides an aluminum alloy material with refined surface grains and a preparation method thereof: An aluminum alloy material with refined surface grains, the aluminum alloy material comprising the following components in terms of mass percentage: Si: 0.3~0.55%; Fe: 0.05~0.36%; Cu: 0.01~0.4%; Mn: 0.01~0.09%; Mg: 0.38~0.62%; Zn: 0.03 ~ 0.08%; Ti: 0.01~0.04%; Cr: 0.01~0.04%; V: 0.01 ~ 0.04%; Na: 0.05 ~ 0.08%; The balance is Al and impurities, and the impurities are ≤ 0.3%; wherein the strengthening phase of the alloy is Mg2Si, the mass ratio of magnesium to silicon is 1.6-1.9, and the Mg2Si content is 0.8-1.1%.

[0004] Preferably, the mass percentage content of Si in the aluminum alloy material is 0.39-0.50%.

[0005] Preferably, the mass percentage content of Fe in the aluminum alloy material is 0.10-0.30%.

[0006] Preferably, the mass percentage content of Mn in the aluminum alloy material is 0.02-0.09%.

[0007] Preferably, the mass percentage content of Mg in the aluminum alloy material is 0.45-0.51%.

[0008] Preferably, the mass percentage content of Cu in the aluminum alloy material is 0.03%.

[0009] Preferably, the mass percentage content of Zn in the aluminum alloy material is 0.04%; the mass percentage content of Ti is 0.02%; the mass percentage content of Cr is 0.03%; the mass percentage content of V is 0.03%; the mass percentage content of Na is 0.07%; A method for preparing aluminum alloy with refined surface grains: S1: Extrusion process: barrel temperature 400-420℃, mold temperature 440-460℃. Ingot temperature 440-460℃. Quenching method adopts natural cooling, extrusion outlet temperature: 460-480℃, post-quenching temperature: ≤100℃, stretching straightening elongation rate 1.0%~1.5%, no orange peel defects on the surface; S2: The extrusion ratio of the split die is between 30-80, and the extrusion ratio of the aluminum alloy is between 25-60 for preparation and molding.

[0010] Beneficial effect: The strengthening phase of the alloy is Mg2Si. The maximum solubility of Mg2Si in aluminum is 1.85%. The higher the concentration of Mg2Si, the higher the strength of the alloy. When the Mg2Si content is 0.8-1.1%, the alloy has good mechanical properties and processing properties. The high Mg2Si content in the alloy can appropriately reduce the extrusion temperature, which is beneficial to suppressing coarse grains. DETAILED DESCRIPTION

[0011] The present invention will be further described below in conjunction with the embodiments.

[0012] Embodiment 1: An aluminum alloy material with refined surface grains, which comprises the following components in percentage by mass: Si: 0.40%; Fe: 0.15%; Cu: 0.03%; Mn: 0.03%; Mg: 0.47%; Zn: 0.04%; Ti: 0.02%; Cr: 0.03%; V: 0.03%; Na: 0.07%, with the remainder being Al and impurities, and the impurities being ≤ 0.3%; wherein the strengthening phase of the alloy is Mg2Si, the mass ratio of magnesium to silicon is 1.6-1.9, and the Mg2Si content is 0.8-1.1%.

[0013] Embodiment 2: An aluminum alloy material with refined surface grains, which comprises the following components in percentage by mass: Si: 0.45%; Fe 0.25%; Cu: 0.03%; Mn: 0.07%; Mg: 0.51%; Zn: 0.04%; Ti: 0.02%; Cr: 0.03%; V: 0.03%; Na: 0.07%, with the remainder being Al and impurities, and the impurities being ≤ 0.3%; wherein the strengthening phase of the alloy is Mg2Si, the mass ratio of magnesium to silicon is 1.6-1.9, and the Mg2Si content is 0.8-1.1%.

[0014] Embodiment 3: An aluminum alloy material with refined surface grains, which comprises the following components in percentage by mass: Si: 0.50%; Fe 0.20%; Cu: 0.03%; Mn: 0.07%; Mg: 0.50%; Zn: 0.04%; Ti: 0.02%; Cr: 0.03%; V: 0.03%; Na: 0.07%, with the remainder being Al and impurities, and the impurities being ≤ 0.3%; wherein the strengthening phase of the alloy is Mg2Si, the mass ratio of magnesium to silicon is 1.6-1.9, and the Mg2Si content is 0.8-1.1%.

[0015] Embodiment 4: An aluminum alloy material with refined surface grains, which comprises the following components in percentage by mass: Si: 0.35%; Fe 0.30%; Cu: 0.03%; Mn: 0.07%; Mg: 0.45%; Zn: 0.04%; Ti: 0.02%; Cr: 0.03%; V: 0.03%; Na: 0.07%, with the remainder being Al and impurities, and the impurities being ≤ 0.3%; wherein the strengthening phase of the alloy is Mg2Si, the mass ratio of magnesium to silicon is 1.6-1.9, and the Mg2Si content is 0.8-1.1%.

[0016] The preparation of the aluminum alloy ingots in the above-mentioned embodiments 1-4 adopts the following steps: S1 extrusion process: barrel temperature 400-420℃, mold temperature 440-460℃. Ingot temperature 440-460℃. Quenching method adopts natural cooling, extrusion outlet temperature: 460-480℃, post-quenching temperature: ≤100℃, stretch straightening elongation rate is 1.0%~1.5%, and there should be no orange peel defects on the surface; S2: the split die extrusion ratio is 30-80, and the aluminum alloy extrusion ratio is between 25-60 to form an aluminum alloy substrate. The finished substrate prepared in the above embodiments 1-4 is sawed into a sample structure of 150mm×50mm×300mm.

[0017] Comparative Examples 1-3: The same type of existing aluminum alloy substrates were sawn into sample structures of the same size of 150mm×50mm×300mm, and corresponding preparation tests were performed. The above Comparative Examples 1-3 respectively selected aluminum alloy substrates from Fujian Xiangxin Co., Ltd., Anan Precision Aluminum Co., Ltd., and Guangdong Jinqiao Aluminum Co., Ltd., which are relatively representative in the existing market.

[0018] The above Examples 1-4 and Comparative Examples 1-3 were all prepared into rectangular aluminum alloy ingot structures (size in mm: 150×50×300) for easy testing, so as to perform aluminum profile pressure tests on their surfaces. By comparing Examples 1-4 with Comparative Examples 1-3, it can be concluded that the performance parameters of the product prepared by the present invention, such as yield strength and tensile strength, are slightly better than those of existing aluminum alloy products of the same type, and the performance parameters such as whether there are coarse ribs in the visual crystal phase after oxidation and the depth of the coarse crystal layer are far better than those of the same type of aluminum alloy. In the actual comparative test, the present invention not only tests the aluminum alloy samples of the above sizes, but also undergoes comparative tests on a large number of samples of various sizes, and the above conclusions can be drawn from all the data.

[0019] A method for preparing surface grains of aluminum profiles: S1: Extrusion process: barrel temperature 400-420℃, mold temperature 440-460℃. Ingot temperature 440-460℃. Quenching method adopts natural cooling, extrusion outlet temperature: 460-480℃, post-quenching temperature: ≤100℃, stretching straightening elongation rate 1.0%~1.5%, no orange peel defects on the surface; S2: The extrusion ratio of the split die is between 30-80, and the extrusion ratio of aluminum alloy is between 25-60. In actual processing, the mold can be designed and adjusted based on the original mold: a. Try to sink the bridge, the width of the bridge bottom is ≤3 mm, b. The step difference between the male head working belt and the lower die working belt is ≤1.0, c. Do not leave a flow-blocking bag, d. The working belt between the two male heads at the inner rib is as short as possible, and the drainage groove has a smooth transition, as large and smooth as possible, e. The lower die working belt is as short as possible, f. No dead zone is left at any place, g. The inlet end is sunken, and the flow supply at the oblique rib is increased: if the working belt is shortened, pay attention to the working belts at both ends of the oblique rib should be shorter than the middle, expand the back hole, etc.; S3: Mold repair method a. Eliminate the dead zone of the two male heads, b. Scrape the choke package flat, c. Reduce the drop between the male head and the lower die working zone, d. Shorten the lower die working zone, repair the upper die with coarse grains in the inner cavity, reduce the lower die working zone and flatten the choke package with coarse grains on the outer surface, and the coarse grains are significantly improved; S4: Use the alkali etching and caustic soda method to quickly verify the surface coarse grains of the extruded white material.

[0020] 3. Optimization of product performance of new process: After dozens of mold repairs and trial mold improvements, the following reasonable solutions are proposed: 1) Mold adjustment: a. Sink the bridge as much as possible, and the width of the bridge bottom is ≤3mm. b. The step difference between the working belt of the male head and the working belt of the lower mold is ≤1.0mm. c. Do not leave a flow-blocking bag. d. The working belt between the two male heads at the inner rib is as short as possible, and the transition of the drainage groove is smooth, as large and smooth as possible. e. The working belt of the lower mold is as short as possible. f. No dead zone is left everywhere (the back empty knife does not exceed 2 mm). g. The coarse grains in the inner cavity are used to repair the upper mold, and the coarse grains on the outer surface are used to reduce the working belt of the lower mold and flatten the flow-blocking bag. You can consider not having the flow-blocking bag and shortening the working belt of the lower mold.

[0021] 2) Mold repair method a. Eliminate the dead zone of the two male heads, b. Scrape the choke package flat, c. Reduce the height difference between the male head and the lower die working zone, d. Shorten the lower die working zone. The coarse grains are significantly improved, and finally we achieve our most ideal effect, which is comparable to that of the same industry. We are the first to solve the coarse grain problem on the surface of many new energy vehicle aluminum profiles, and obtain a nearly perfect profile without coarse grains.

[0022] Obviously, the above embodiments of the present invention are merely examples for illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to exhaust all implementation methods here. However, these obvious changes or modifications derived from the essential spirit of the present invention still fall within the protection scope of the present invention.

Claims

1. An aluminum alloy material with refined surface grains, characterized in that: The aluminum alloy material comprises the following components in terms of mass percentage: Si: 0.3~0.55%; Fe: 0.05~0.36%; Cu: 0.01~0.4%; Mn: 0.01~0.09%; Mg: 0.38~0.62%; Zn: 0.03 ~ 0.08%; Ti: 0.01~0.04%; Cr：0.01 ～0.04％； V：0.01 ～0.04％； Na: 0.05 ~ 0.08%; The balance is Al and impurities, and the impurities are ≤ 0.3%; wherein the strengthening phase of the alloy is Mg2Si, the mass ratio of magnesium to silicon is 1.6-1.9, and the Mg2Si content is 0.8-1.1%.

2. The aluminum alloy material with refined surface grains according to claim 1, characterized in that: The mass percentage content of Si in the aluminum alloy material is 0.39-0.50%.

3. The aluminum alloy material with refined surface grains according to claim 1, characterized in that: The mass percentage content of Fe in the aluminum alloy material is 0.10-0.30%.

4. The aluminum alloy material with refined surface grains according to claim 1, characterized in that: The mass percentage content of Mn in the aluminum alloy material is 0.02-0.09%.

5. The aluminum alloy material with refined surface grains according to claim 1, characterized in that: The mass percentage content of Mg in the aluminum alloy material is 0.45-0.51%.

6. The aluminum alloy material with refined surface grains according to claim 1, characterized in that: The mass percentage content of Cu in the aluminum alloy material is 0.03%.

7. The aluminum alloy material with refined surface grains according to claim 1, characterized in that: The aluminum alloy material contains 0.04% by mass of Zn, 0.02% by mass of Ti, 0.03% by mass of Cr, 0.03% by mass of V, and 0.07% by mass of Na.

8. A method for preparing aluminum alloy with refined surface grains: S1: Extrusion process: barrel temperature 400-420℃, mold temperature 440-460℃, ingot temperature 440-460℃, quenching method adopts natural cooling, extrusion outlet temperature: 460-480℃, post-quenching temperature: ≤100℃, stretching straightening elongation rate is 1.0%~1.5%, and there should be no orange peel defects on the surface; S2: The extrusion ratio of the split die is between 30-80, and the extrusion ratio of the aluminum alloy is between 25-60 for preparation and molding.