6-series aluminum alloy for consumer electronics with high si content and processing technology thereof

Abstract

The application discloses a 6-series aluminum alloy with high Si content for consumer electronics and a processing technology thereof, and is characterized in that the 6-series aluminum alloy comprises the following components in percentage by mass: Mg 0.7-1.0 wt.%, Si 1.0-1.5 wt.%, Cu 0.5-1.3 wt.%, Mn 0.02-0.2 wt.%, Fe≤0.2 wt.%, Cr≤0.2 wt.%, Ti≤0.1 wt.%, and the rest is Al and inevitable impurities. The 6-series aluminum alloy material with high Si content has high strength, good anode appearance and high extrusion processing efficiency through adjustment of the contents of Mg, Si and other elements and process control, and is suitable for application in the field of consumer electronic aluminum materials.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloys, and more particularly to a high-Si-content 6-series aluminum alloy for consumer electronics and its processing technology. Background Technology

[0002] Currently, the 6-series aluminum alloys used in consumer electronics are 6063 or 6013 type aluminum alloys. These are characterized by a higher Mg content than Si content, resulting in higher strength and better anodizing performance. The reason for maintaining a high Mg content in these alloys is that high Si content can easily cause graying on the anodized surface, leading to a dull appearance and other defects. However, high-Si alloys typically have higher extrusion speeds (efficiencies), which helps improve production efficiency and reduce costs.

[0003] Therefore, it is necessary to develop a high-Si-content aluminum alloy material for consumer electronics without compromising the appearance of the material's anode. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a high-Si-content 6-series aluminum alloy for consumer electronics and its processing technology, which has low processing cost, high processing efficiency, high mechanical strength of the aluminum alloy, and good anodizing effect.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] Firstly, this invention provides a high-Si-content 6-series aluminum alloy for consumer electronics, comprising, by mass percentage:

[0007]

[0008]

[0009] The total mass of unavoidable impurities is ≤0.5 wt.%, with the balance being Al.

[0010] Preferably, the surface fraction of the aluminum alloy microstructure with a size larger than that of the coarse intermetallic compound is ≥5%.

[0011] Secondly, this invention provides a processing technology for high-Si-content 6-series aluminum alloys for consumer electronics, which includes the following steps:

[0012] Raw materials are weighed according to the mass percentage of each element in the aluminum alloy composition and then smelted and cast to obtain ingots.

[0013] The ingots are subjected to homogeneous annealing, held at 500-560℃ for 20-30 hours, and then cooled to room temperature at a rate of ≤100℃ / h.

[0014] After homogenization, the material is extruded at a bar temperature of 500–560°C and an extruded material outlet temperature of 500–540°C.

[0015] The extruded material is subjected to aging treatment, and kept at 185-200℃ for 4-12 hours.

[0016] In 6-series aluminum alloys, increasing the Mg or Si content can improve the material's strength, but increasing Si will cause the surface to turn gray after anodizing; while increasing Mg will easily reduce the material's extrusion deformation rate. In this invention, Mg 0.7–1.0 wt.% and Si 1.0–1.5 wt.% can give the material high strength, but may cause the surface to darken and turn gray during subsequent anodizing.

[0017] Therefore, the present invention further optimizes other components and processes to reduce the impact of Si on the anode effect.

[0018] Regarding composition: First, the Mn content is controlled between 0.02 and 0.2 wt.%, which helps form Mn-Si compounds, reducing the Si content in the matrix. Mn also refines the grain size. Second, the Cu content is controlled between 0.5 and 1.3 wt.%, which helps form Cu-Si compounds. Cu also strengthens the material. Finally, Fe, Cr, and Ti have relatively little impact on microstructure and properties, so their contents are limited to Fe ≤ 0.2 wt.%, Cr ≤ 0.2 wt.%, and Ti ≤ 0.1 wt.%.

[0019] Regarding the component processing technology: the ingots containing the above components are homogenized and held at 500-560℃ for 20-30 hours, and then cooled to room temperature at a rate not exceeding 100℃ / h; the homogenized material is extruded at a bar temperature of 500-560℃ and an extruded material outlet temperature of 500-540℃; the aging process is held at 185-200℃ for 4-12 hours. The purpose of homogenization is to dissolve coarse Mg2Si, preparing for subsequent strengthening. This process requires a certain temperature and time, such as holding at 500–560℃ for 20–30 hours. Limiting the cooling rate is to promote the precipitation of Si-containing intermetallic compounds during the cooling process, avoiding the adverse effects of high Si content on anodizing. Controlling the bar temperature and exit temperature during extrusion is for forming and to give the material higher strength. The aging regime of holding at 185–200℃ for 4–12 hours is to improve mechanical properties. On the other hand, over-aging can promote the precipitation of coarse Si-containing compounds, further reducing the adverse effects of Si on the anode.

[0020] This invention, by adjusting the content of elements such as Mg and Si and controlling the process, enables high-Si-content 6-series aluminum alloy materials to possess both high strength and anodized appearance, as well as high extrusion processing efficiency, making them suitable for consumer electronics aluminum material applications. Detailed Implementation

[0021] 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, and not for limiting the scope of the claims of the present invention.

[0022] Example 1

[0023] The aluminum alloy composition, by mass percentage, is: Mg 0.7wt.%, Si 1.5wt.%, Mn 0.2wt.%, Cr 0.2wt.%, Cu 0.5wt.%, Ti 0.1wt.%, Fe 0.2wt.%, unavoidable impurities ≤0.5wt.%, balance Al;

[0024] The raw materials are weighed according to the mass percentage of each element in the above aluminum alloy and then smelted and cast to obtain ingots.

[0025] The ingot is subjected to homogeneous annealing. The ingot is heated to 500℃ at a rate of 50℃ / h and held for 30h, and then cooled to room temperature at a rate of 80℃ / h.

[0026] The homogenized material was extruded at a bar temperature of 560℃, an extruded material outlet temperature of 540℃, and an extrusion speed of 11m / min.

[0027] The extruded material is subjected to aging treatment, and the resulting extruded material is heated to 185℃ at a rate of 5℃ / h and held for 12h.

[0028] Example 2

[0029] The aluminum alloy composition, by mass percentage, is: Mg 1.0 wt.%, Si 1 wt.%, Mn 0.02 wt.%, Cr 0.11 wt.%, Cu 1.3 wt.%, Ti 0.03 wt.%, Fe 0.10 wt.%.

[0030] The raw materials are weighed according to the mass percentage of each element in the above aluminum alloy and then smelted and cast to obtain ingots.

[0031] The ingot is subjected to homogeneous annealing. The ingot is heated to 560℃ at a rate of 80℃ / h and held for 20h, and then cooled to room temperature at a rate of 90℃ / h.

[0032] The homogenized material is extruded at a bar temperature of 500℃, an extruded material outlet temperature of 500℃, and an extrusion speed of 13m / min.

[0033] The extruded material is subjected to aging treatment, and the resulting extruded material is heated to 200℃ at a rate of 10℃ / h and held for 4h.

[0034] Example 3

[0035] The aluminum alloy composition, by mass percentage, is: Mg 0.8 wt.%, Si 1.2 wt.%, Mn 0.1 wt.%, Cr 0.11 wt.%, Cu 0.8 wt.%, Ti 0.04 wt.%, Fe 0.12 wt.%, unavoidable impurities ≤0.5 wt.%, balance Al;

[0036] The raw materials are weighed according to the mass percentage of each element in the above aluminum alloy and then smelted and cast to obtain ingots.

[0037] The ingots were subjected to homogeneous annealing. The ingots were heated to 530℃ at a rate of 60℃ / h and held at that temperature for 22h, and then cooled to room temperature at a rate of 100℃ / h.

[0038] The homogenized material was extruded at a bar temperature of 540℃, an extruded material outlet temperature of 530℃, and an extrusion speed of 12m / min.

[0039] The extruded material is subjected to aging treatment, and the resulting extruded material is heated to 195℃ at a rate of 8℃ / h and held for 5h.

[0040] Comparative Example 1

[0041] The aluminum alloy composition, by mass percentage, is: Mg 1.2 wt.%, Si 0.5 wt.%, Mn 0.2 wt.%, Cr 0.30 wt.%, Cu 0.45 wt.%, Ti 0.25 wt.%, Fe 0.19 wt.%.

[0042] In Comparative Example 1, the aluminum alloy processing technology is the same as that in Example 1, and the extrusion speed is 8 m / min.

[0043] Comparative Example 2

[0044] The composition of the aluminum alloy in Comparative Example 2 is the same as that in Example 1.

[0045] However, the following processing technology is adopted:

[0046] Raw materials are weighed according to the mass percentage of each element in the aluminum alloy and then smelted and cast to obtain ingots.

[0047] The ingot is subjected to homogeneous annealing. The ingot is heated to 500℃ at a rate of 50℃ / h and held at that temperature for 30h, and then cooled to room temperature at a rate of 200℃ / h.

[0048] The homogenized material is extruded at a bar temperature of 560℃, an extruded material outlet temperature of 540℃, and an extrusion speed of 12m / min.

[0049] The extruded material is subjected to aging treatment, and the resulting extruded material is heated to 175℃ at a rate of 5℃ / h and held for 12h.

[0050] According to GB / T6892-2015 "Aluminum and Aluminum Alloy Extruded Profiles for General Industrial Use", 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 alloys in Examples 1-3 and Comparative Examples 1-2.

[0051] Table 1

[0052]

[0053] As shown in Table 1, by reasonably adjusting the content of each element in the aluminum alloy and the processing technology, the present invention enables the material to have high strength, high anodizing effect and high extrusion speed, making it suitable for large-scale production of aluminum materials for consumer electronics.

[0054] Based on the disclosure in the foregoing specification, those skilled in the art can 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 protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A high-Si-content 6-series aluminum alloy for consumer electronics, characterized in that: By mass percentage, it includes: Mg 0.7 wt.%, Si 1.5 wt.%, Mn 0.2 wt.%, Cr 0.2 wt.%, Cu 0.5 wt.%, Ti 0.1 wt.%, Fe 0.2 wt.%, unavoidable impurities ≤0.5 wt.%, balance Al; The processing technology for the high-Si-content 6-series aluminum alloy for consumer electronics includes the following steps: Raw materials are weighed according to the mass percentage of each element in the aluminum alloy composition and then smelted and cast to obtain ingots. The ingot is subjected to homogeneous annealing. The ingot is heated to 500℃ at a rate of 50℃ / h and held for 30h, and then cooled to room temperature at a rate of 80℃ / h. The homogenized material was extruded at a bar temperature of 560℃, an extruded material outlet temperature of 540℃, and an extrusion speed of 11m / min. The extruded material is subjected to aging treatment, and the resulting extruded material is heated to 185℃ at a rate of 5℃ / h and held for 12h. The surface fraction of coarse intermetallic compounds in the microstructure of the 6-series aluminum alloy is 8.5%.

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