High-strength 6-series aluminum alloy for sand blasting back plate and processing technology of high-strength 6-series aluminum alloy

Abstract

The processing technology comprises the following steps: weighing 1.1 to 2.0 weight percent of Mg, 0.6 to 1.5 weight percent of Si, 0.8 to 2.0 weight percent of Cu, 0.02 to 0.10 weight percent of Mn, less than or equal to 0.15 weight percent of Fe, less than or equal to 0.2 weight percent of Cr, less than or equal to 0.05 weight percent of Ti, less than or equal to 0.5 weight percent of total mass of inevitable impurities and the balance of Al according to mass percent, and carrying out ingot casting; carrying out homogenization treatment on the cast ingot; extruding the homogenized material, keeping the temperature of a cast ingot in an extrusion cylinder for 10-50 seconds, and then starting to extrude; and the extruded material is subjected to aging treatment, and the aluminum alloy material is obtained. By adjusting the contents of elements such as Mg, Si, Cu, Mn, Ti and the like and controlling the process, the 6-series aluminum alloy material has a relatively excellent microstructure while obtaining high strength, so that a high sand blasting anode appearance effect is obtained, and the method is suitable for the application field of consumer electronic aluminum materials.

Description

Technical Field

[0001] The invention relates to the field of aluminum alloys, and in particular to a high-strength 6-series aluminum alloy for a sandblasting back plate and a processing technology thereof. Background Art

[0002] The demand for thinning consumer electronic products has become an application trend in the entire industry. In order to meet this development demand, the strength of the aluminum alloy shell used in the product needs to be further increased. Usually, 6013 aluminum alloy is used to make the shell, and its yield strength is 300-380MPa. In order to further increase the strength of 6013 aluminum alloy, the alloying level can be increased, such as increasing the content of Mg, Si, and Cu or adding transition elements. However, although increasing the content of Mg, Si, and Cu can increase the strength of the material, it is easy to form a large number of corresponding compounds in the organization, resulting in appearance defects (such as anode grains); adding transition elements, such as Mn, Zr, and Cr, will form fibrous structures in the organization, resulting in fiber crystal strengthening, but it will also cause organization and anode grains, and cannot be used in appearance parts. Therefore, it is necessary to develop a high-strength 6 series aluminum alloy and its processing technology in response to the needs of the industry. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a high-strength 6-series aluminum alloy for sandblasting back panels and a processing technology thereof, which is suitable for the application field of consumer electronic aluminum materials.

[0004] The purpose of the present invention is achieved through the following technical solutions: First, the present invention provides a high-strength 6-series aluminum alloy for a sandblasting back plate, which includes, by mass percentage, Mg 1.1-2.0 wt.%, Si 0.6-1.5 wt.%, Cu 0.8-2.0 wt.%, Mn 0.02-0.10 wt.%, Fe ≤0.15 wt.%, Cr ≤0.2 wt.%, Ti ≤0.05 wt.%, the total mass of unavoidable impurities ≤0.5 wt.%, and the balance is Al.

[0005] Furthermore, the tensile strength of the high-strength 6-series aluminum alloy used for the sandblasting back plate is ≥430MPa, and the yield strength is ≥400MPa.

[0006] Secondly, the present invention provides a processing technology for the high-strength 6-series aluminum alloy for the sandblasting back plate, which comprises the following steps: Weigh raw materials according to the mass percentage of each element in the aluminum alloy, and perform smelting and casting to obtain an ingot; The ingot is homogenized, and the temperature is increased from room temperature to 500-580°C at a heating rate of 10-30°C / h, and kept at this temperature for 5-20h; The homogenized material is extruded, the extrusion rod temperature is 530-560°C, the extrusion barrel temperature is 380-460°C, the ingot is kept warm in the extrusion barrel for 10-50 seconds before extrusion begins, and the outlet temperature of the extruded material is 480-520°C; Aging treatment of extruded materials.

[0007] Furthermore, the homogenized material is extruded, and the Mg content in the extruded material is 2 The volume fraction of Si is greater than 5%.

[0008] Furthermore, the extruded material is subjected to aging treatment by keeping the extruded material at 185-200° C. for 2-20 hours.

[0009] The beneficial effects of the present invention are: In 6 series aluminum alloys, Mg, Si, and Cu are the main added elements. Their content levels determine the mechanical properties of the material. The greater the amount added, the higher the strength. However, too high an alloying content will cause too many insoluble compounds in the material. When these compounds are distributed linearly, sandblasting anode material lines will be caused. At the same time, if the alloy composition is too high, problems such as slow extrusion speed and extrusion cracking will be caused, which will reduce production efficiency and increase production costs. In general, the contents of Mg, Si, and Cu are 1.1-2.0 wt.%, 0.6-1.5 wt.%, and 0.8-2.0 wt.%, respectively, which can make the aluminum alloy have higher strength and avoid problems such as extrusion cracking caused by high strength.

[0010] Mn is a trace element added mainly to control the grain size, but it is easy to form fibrous grains in the structure to cause anode material lines, and its content is preferably 0.02-0.10wt.%. Ti is a trace element mainly used to control the cast grains. As long as the cast grains are within the required range, its content can be ≤0.05wt.%.

[0011] Fe and Cr elements are impurities, and their contents should be Cr ≤ 0.2 wt.%, and Fe ≤ 0.15 wt.%, otherwise it is easy to cause material grains in the organization.

[0012] The ingots of the above composition are homogenized, heated from room temperature to 500-580°C at a heating rate of 10°C-30°C / h, and kept warm for 5-20h. The heating rate is controlled to dissolve some soluble compounds during the heating process and promote the nucleation of the Mn-containing phase; while the holding temperature and holding time are controlled to fully dissolve the second phase, and also to prepare for the subsequent pre-precipitation of the second phase during the extrusion process. The homogenized material is extruded, the extrusion rod temperature is 530-560°C, the extrusion barrel temperature is 380-460°C, and the outlet temperature of the homogenized rod in the barrel is 480-520°C. Controlling the extrusion rod temperature, barrel temperature, and outlet temperature is to facilitate material molding and obtain higher strength; further, during the material extrusion process, the ingot is kept warm in the extrusion barrel for 10-50 seconds before extrusion begins. After the ingot is kept at high temperature, it is in a supersaturated state of solute. If the temperature of the extruder is low and the ingot is kept at this time, it is easy to precipitate dense and evenly distributed Mg in the structure. 2 Si phase. Such a structure is not easy to form strip-shaped metal compound belts in the subsequent extrusion process, but is conducive to the control of material grain; after that, the extruded material is subjected to aging treatment, and the temperature is kept at 185-200℃ for 2-20h to further improve the strength of the material through aging.

[0013] The present invention adjusts the content of elements such as Mg, Si, Cu, Mn, Ti and controls the process so that the material has high strength and better microstructure, thereby obtaining a high sandblasting anode appearance effect, which is suitable for the application field of consumer electronic aluminum materials. DETAILED DESCRIPTION

[0014] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0015] Example 1 The composition of the 6 series aluminum alloy is calculated by mass percentage as follows: Mg 1.1wt.%, Si 1.5wt.%, Mn 0.1wt.%, Cr0.2wt.%, Cu 2.0wt.%, Ti 0.05wt%, Fe 0.15wt%, inevitable impurities ≤0.5wt%, and the balance is Al; Weigh raw materials according to the mass percentage of each element in the aluminum alloy, and perform smelting and casting to obtain an ingot; The ingot with the above composition is homogenized, heated from room temperature to 500°C at a heating rate of 10°C / h, and kept at this temperature for 20h; The homogenized material was extruded, the extrusion rod temperature was 530℃, the extrusion barrel temperature was 460℃, the ingot was kept warm in the extrusion barrel for 10 seconds before extrusion began, the homogenized rod extrusion material outlet temperature in the barrel was 520℃, and the extrusion speed during the extrusion process was 13m / min; The extruded material was subjected to aging treatment at 185°C for 20 hours.

[0016] Example 2 The composition of the 6 series aluminum alloy is calculated by mass percentage as follows: Mg 2.0wt.%, Si 0.6wt.%, Mn 0.02wt%, Cr0.05wt%, Cu 0.8 wt.%, Ti 0.008wt%, Fe 0.06wt%, inevitable impurities ≤0.5wt%, and the balance is Al; Weigh raw materials according to the mass percentage of each element in the aluminum alloy, and perform smelting and casting to obtain an ingot; The ingot with the above composition is homogenized, heated from room temperature to 580°C at a heating rate of 30°C / h, and kept at this temperature for 5h; The homogenized material is extruded, the extrusion rod temperature is 560℃, the extrusion barrel temperature is 380℃, the ingot is kept warm in the extrusion barrel for 50 seconds before extrusion begins, the homogenized rod extrusion material outlet temperature in the barrel is 480℃, and the extrusion speed during the extrusion process is 13m / min; The extruded material was subjected to aging treatment at 185°C for 20 hours.

[0017] Example 3 The composition of the 6 series aluminum alloy is calculated by mass percentage as follows: Mg 1.2 wt.%, Si 1.0 wt.%, Mn 0.08wt.%, Cr 0.03wt.%, Cu 1.2 wt.%, Ti 0.03wt.%, Fe 0.12wt%, the total mass of inevitable impurities ≤0.5wt.%, and the balance is Al.

[0018] Weigh raw materials according to the mass percentage of each element in the aluminum alloy, and perform smelting and casting to obtain an ingot; The ingot with the above composition is homogenized, heated from room temperature to 560°C at a heating rate of 15°C / h, and kept at this temperature for 15h; The homogenized material is extruded, the extrusion rod temperature is 540℃, the extrusion barrel temperature is 420℃, the ingot is kept warm in the extrusion barrel for 30 seconds before extrusion begins, the homogenized rod in the barrel has an extrusion material outlet temperature of 500℃, and the extrusion speed during the extrusion process is 13m / min; The extruded material was subjected to aging treatment at 190°C for 8 hours.

[0019] Comparative Example 1 The composition of the 6 series aluminum alloy is calculated by mass percentage as follows: Mg 1.2 wt.%, Si 0.8wt.%, Mn 0.5wt.%, Cr0.70wt.%, Cu 2.1wt.%, Ti 0.25wt.%, Fe 0.19wt.%, the total mass of inevitable impurities ≤0.5wt.%, and the balance is Al.

[0020] The processing technology of the aluminum alloy in Comparative Example 1 is consistent with that in Example 1.

[0021] Comparative Example 2 The composition of the aluminum alloy in Comparative Example 2 is consistent with that in Example 1.

[0022] The ingot of the above composition is homogenized at 500°C and kept at this temperature for 20 hours; The homogenized material is extruded, the extrusion rod temperature is 500°C, and the extrusion material outlet temperature is 530°C; Aging treatment of extruded materials: 185℃ for 20h.

[0023] According to the standard GB / T6892-2015 "General Industrial Aluminum and Aluminum Alloy Extrusion Profiles", the performance of each aluminum alloy in Examples 1 to 3 and Comparative Examples 1 to 2 was tested. Table 1 shows the performance and microstructure characteristics of the aluminum alloy in Examples 1-3 and Comparative Examples 1-2.

[0024] Table 1

[0025] The present invention reasonably adjusts the content of each element in the aluminum alloy and the processing technology, so that the material has a higher strength and a higher sandblasting anode appearance effect, and is suitable for large-scale production of consumer electronic aluminum materials.

[0026] According to the disclosure of the above description, those skilled in the art to which the present invention belongs may also make appropriate changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the scope of protection of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A high-strength 6-series aluminum alloy for a sandblasting back plate, characterized in that: Calculated in mass percentage, it includes: Mg 1.1-2.0wt.%, Si 0.6-1.5wt.%, Cu 0.8-2.0wt.%, Mn 0.02-0.10wt.%, Fe ≤0.15wt.%, Cr≤0.2wt.%, Ti ≤0.05wt.%, the total mass of unavoidable impurities ≤0.5wt.%, and the balance is Al.

2. The high-strength 6-series aluminum alloy for sandblasting back plate according to claim 1, characterized in that: The tensile strength of the high-strength 6-series aluminum alloy used for the sandblasting back plate is ≥430MPa, and the yield strength is ≥400MPa.

3. A processing technology for high-strength 6-series aluminum alloy for sandblasting back plate according to claim 1 or 2, characterized in that: The steps include: Weigh raw materials according to the mass percentage of each element in the aluminum alloy, and perform smelting and casting to obtain an ingot; The ingot is homogenized, and the temperature is increased from room temperature to 500-580°C at a heating rate of 10-30°C / h, and kept at this temperature for 5-20h; The homogenized material is extruded, the extrusion rod temperature is 530-560°C, the extrusion barrel temperature is 380-460°C, the ingot is kept warm in the extrusion barrel for 10-50 seconds before extrusion begins, and the outlet temperature of the extruded material is 480-520°C; Aging treatment of extruded materials.

4. The processing technology of high-strength 6-series aluminum alloy for sandblasting back plate according to claim 3 is characterized in that: The homogenized material is extruded, and the volume fraction of Mg2Si in the extruded material is greater than 5%.

5. The processing technology of high-strength 6-series aluminum alloy for sandblasting back plate according to claim 3 is characterized in that: The extruded material is subjected to aging treatment by keeping the extruded material at 185-200°C for 2-20 hours.

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