High-strength 6xxx series fine grain aluminum alloy for 3C products and manufacturing method of high-strength 6xxx series fine grain aluminum alloy

Abstract

The invention discloses a high-strength 6xxx series fine grain aluminum alloy for 3C products and a manufacturing method of the high-strength 6xxx series fine grain aluminum alloy. The high-strength 6xxx series fine grain aluminum alloy comprises, by weight, 0.7%-1.2% of Si, smaller than or equal to 0.20% of Fe, 0.7%-1.2% of Cu, 0.4%-0.8% of Mn, 0.8%-1.1% of Mg, smaller than or equal to 0.1% of Cr, smaller than or equal to 0.25% of Zn, smaller than or equal to 0.1% of Ti, 0.03%-0.09% of Sc, 4.65%-6.65% of aluminum-titanium-carbon intermediate alloy and the balance aluminum. By adding the aluminum-titanium-carbon intermediate alloy, the refining capacity and aging are efficiently improved; the melt purification of the aluminum alloy is facilitated, and the metallurgical quality of an aluminum alloy product is improved; the aluminum alloy cast ingot can obtain grains with uniform and consistent sizes from the surface to the center, and the final use performance of the product is improved; the intergranular corrosion rate can be reduced, and the corrosion resistance of an aluminum alloy product is improved; refining poisoning can be effectively overcome, and the casting quality of the high-strength and heat-resistant aluminum alloy is improved. The manufactured high-strength 6xxx series fine grain aluminum alloy has the following advantages that the alloy performance is that the yield strength is larger than or equal to 430 MPa, the tensile strength is larger than or equal to 450 MPa, and the ductility is larger than or equal to 10%; the average grain size is smaller than or equal to 150 microns, and the maximum grain size is smaller than or equal to 300 microns.

Description

Technical Field

[0001] The present invention relates to the technical field of high-strength 6xxx series fine-grained aluminum alloys, and in particular to a high-strength 6xxx series fine-grained aluminum alloy for 3C products and a manufacturing method thereof. Background Art

[0002] 6xxx series aluminum alloys are widely used in the manufacture of 3C product appearance parts due to their high strength and good anodizing effect. Usually, oxidation is required to achieve a high-gloss effect, and the size of the aluminum alloy grains plays a decisive role in the effect after oxidation. In order to obtain a better appearance effect, the current requirement is to ensure that the average grain size of aluminum alloy ingots and subsequent extrusions is less than 150μm. There are many ways to control grain refinement, including the control of aluminum alloy composition and trace elements; the type, method and amount of grain refiner materials; mold design and homogenization heat treatment process; the purpose is to obtain a relatively pure aluminum solution, a relatively fine grain structure, and improve the mechanical properties of alloy products.

[0003] At present, aluminum titanium boron is the most widely used aluminum alloy grain refiner, which can effectively improve the internal structure of aluminum alloy. 2 Factors such as coarse particle size and agglomeration have caused various quality problems for many products: ① Scratches or streaks appear on the surface of some aluminum rolled plates, pinholes appear on aluminum foil, and gold damages the surface of the roll; ② TiB 2 Agglomerates are easy to precipitate, causing refinement decay and clogging the filter, affecting the filtering effect; ③ Zr and Cr elements in some high-strength aluminum alloys will cause Al-Ti-B refinement poisoning, forming coarse grains or uneven structure.

[0004] With the widespread application of aluminum alloy products in 3C products, especially the continuous emergence of high-end aluminum alloy new materials, higher requirements are placed on product quality. The application of aluminum alloy grain refinement methods has developed rapidly. Due to its various natural advantages, the market demand for Al-Ti-C alloy will gradually expand and it has a good market prospect. Summary of the invention

[0005] The object of the present invention is to provide a high-strength 6xxx series fine-grained aluminum alloy for 3C products and a method for manufacturing the same, so as to solve the problems raised in the background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a high-strength 6xxx series fine-grained aluminum alloy for 3C products, comprising the following weight percentages: Si 0.7-1.2%, Fe≤0.20%, Cu 0.7-1.2%, Mn 0.4-0.8%, Mg 0.8-1.1%, Cr≤0.1%, Zn≤0.25%, Ti≤0.1%, Sc 0.03-0.09% and aluminum-titanium-carbon master alloy 4.65-6.65%, and the balance is aluminum.

[0007] Preferably, it includes the following weight percentages: Si 1%, Fe 0.20%, Cu 0.7%, Mn 0.5%, Mg 0.8%, Cr 0.1%, Zn 0.25%, Ti 0.1%, Sc 0.05% and aluminum-titanium-carbon master alloy 5%, and the balance is aluminum.

[0008] Preferably, it includes the following weight percentages: Si 0.7%, Fe 0.1%, Cu 1.0%, Mn 0.6%, Mg 1.1%, Cr0.05%, Zn 0.15%, Ti 0.05%, Sc 0.06% and aluminum-titanium-carbon master alloy 6%, and the balance is aluminum.

[0009] Preferably, the aluminum-titanium-carbon master alloy includes the following weight percentages: Si≤0.20%, Fe≤0.15%, V≤0.05%, Cr≤0.15%, Ni≤0.15%, Ti 4.5-5.5%, C 0.15-0.25%, other individual impurity content <0.10%, total impurity content <0.10%, and the balance is aluminum.

[0010] A method for manufacturing a high-strength 6xxx series fine-grained aluminum alloy for 3C products comprises the following steps: Step 1: weigh pure aluminum, aluminum-titanium-carbon master alloy, other master alloys and refining agents according to a certain proportion and dry them all; Step 2: Place pure aluminum ingots in a smelting furnace and heat until completely melted; Step 3, when the temperature rises to 700-800°C, add other master alloys except the aluminum-titanium-carbon master alloy and wait for them to be completely melted; Step 4: When the temperature reaches 740-760°C, add refining agent to degas and slag; Step 5: When the temperature reaches 740-760°C, add aluminum-titanium-carbon master alloy; Step 6: After the aluminum-titanium-carbon master alloy is completely melted, the molten metal liquid is stirred; Step 7: When the temperature drops to 710-730°C, the molten metal is cast to obtain a high-strength 6xxx series fine-grained aluminum alloy.

[0011] Preferably, in step one, other master alloys include: Si 0.7-1.2%, Fe≤0.20%, Cu 0.7-1.2%, Mn 0.4-0.8%, Mg 0.8-1.1%, Cr≤0.1%, Zn≤0.25%, Ti≤0.1%, and Sc 0.03-0.09%.

[0012] Preferably, in step 1, the components of the refining agent include the following weight percentages: KCl 35-50%, NaCl 30-40%, CaF 2 5-8%, Na 3 AlF 6 8-15%, Mg 2 N 3 5-10%, C 2 Cl 6 3-6% and rare earth 0.2-0.5%.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention adds aluminum-titanium-carbon master alloy, which has high efficiency and time-effectiveness in refinement. It is beneficial to the melt purification of aluminum alloy and improves the metallurgical quality of aluminum alloy products. It can make aluminum alloy ingots obtain grains with uniform size from the surface to the center, and improve the final use performance of the product. It can reduce the intergranular corrosion rate and improve the corrosion resistance of aluminum alloy products. It can effectively overcome refinement "poisoning" and improve the casting quality of high-strength and heat-resistant aluminum alloys. The manufactured high-strength 6xxx series fine-grained aluminum alloy has the following advantages: alloy properties: yield strength ≥430MPa, tensile strength ≥450MPa, elongation ≥10%; grain size: average grain size ≤150μm, maximum grain size ≤300μm. DETAILED DESCRIPTION

[0014] The following will be combined with 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 making creative work are within the scope of protection of the present invention.

[0015] The present invention provides a high-strength 6xxx series fine-grained aluminum alloy for 3C products, comprising the following weight percentages: Si 0.7-1.2%, Fe ≤ 0.20%, Cu 0.7-1.2%, Mn 0.4-0.8%, Mg 0.8-1.1%, Cr ≤ 0.1%, Zn ≤ 0.25%, Ti ≤ 0.1%, Sc 0.03-0.09% and aluminum-titanium-carbon master alloy 4.65-6.65%, and the balance is aluminum. The aluminum-titanium-carbon master alloy comprises the following weight percentages: Si ≤ 0.20%, Fe ≤ 0.15%, V ≤ 0.05%, Cr ≤ 0.15%, Ni ≤ 0.15%, Ti 4.5-5.5%, C 0.15-0.25%, other single impurity content < 0.10%, total impurity content < 0.10%, and the balance is aluminum.

[0016] A method for manufacturing a high-strength 6xxx series fine-grained aluminum alloy for 3C products comprises the following steps: Step 1: weigh pure aluminum, aluminum-titanium-carbon master alloy, other master alloys and refining agent in a certain proportion and dry them all; the refining agent comprises the following weight percentages: KCl 35-50%, NaCl 30-40%, CaF 2 5-8%, Na 3 AlF 6 8-15%, Mg 2 N 3 5-10%, C 2 Cl 6 3-6% and rare earth 0.2-0.5%; Step 2: Place pure aluminum ingots in a smelting furnace and heat until completely melted; Step 3, when the temperature rises to 700-800°C, add other master alloys except the aluminum-titanium-carbon master alloy and wait for them to be completely melted; Step 4: When the temperature reaches 740-760°C, add refining agent to degas and slag; Step 5: When the temperature reaches 740-760°C, add aluminum-titanium-carbon master alloy; Step 6: After the aluminum-titanium-carbon master alloy is completely melted, the molten metal liquid is stirred; Step 7: When the temperature drops to 710-730°C, the molten metal is cast to obtain a high-strength 6xxx series fine-grained aluminum alloy. Example

[0017] A method for manufacturing a high-strength 6xxx series fine-grained aluminum alloy for 3C products comprises the following steps: Step 1: weigh Si 1%, Fe 0.20%, Cu 0.7%, Mn 0.5%, Mg 0.8%, Cr 0.1%, Zn 0.25%, Ti 0.1%, Sc 0.05% and aluminum-titanium-carbon master alloy 5% and a refining agent of 0.3% of the total weight of the above alloys according to a certain proportion and dry them all; the refining agent comprises the following weight percentages: KCl 35-50%, NaCl 30-40%, CaF 2 5-8%, Na 3 AlF 6 8-15%, Mg 2 N 3 5-10%, C 2 Cl 6 3-6% and rare earth 0.2-0.5%; Step 2: Place pure aluminum ingots in a smelting furnace and heat until completely melted; Step 3, when the temperature rises to 750° C., add other master alloys except the aluminum-titanium-carbon master alloy and wait for them to be completely melted; Step 4: When the temperature reaches 750°C, add refining agent to degas and slag; Step 5: When the temperature reaches 750°C, add aluminum-titanium-carbon master alloy; Step 6: After the aluminum-titanium-carbon master alloy is completely melted, the molten metal liquid is stirred; Step seven: when the temperature drops to 720°C, the molten metal is cast to obtain a high-strength 6xxx series fine-grained aluminum alloy. Example

[0018] A method for manufacturing a high-strength 6xxx series fine-grained aluminum alloy for 3C products comprises the following steps: Step 1: Weigh Si 0.7%, Fe 0.1%, Cu 1.0%, Mn 0.6%, Mg 1.1%, Cr0.05%, Zn 0.15%, Ti 0.05%, Sc 0.06% and aluminum-titanium-carbon master alloy 6% and a refining agent of 0.3% of the total weight of the above alloys according to a certain proportion and dry them all; the refining agent includes the following weight percentages: KCl 35-50%, NaCl 30-40%, CaF 2 5-8%, Na 3 AlF 6 8-15%, Mg 2 N 3 5-10%, C 2 Cl 6 3-6% and rare earth 0.2-0.5%; Step 2: Place pure aluminum ingots in a smelting furnace and heat until completely melted; Step 3, when the temperature rises to 730°C, add other master alloys except the aluminum-titanium-carbon master alloy and wait for them to be completely melted; Step 4: When the temperature reaches 750°C, add refining agent to degas and slag; Step 5: When the temperature reaches 750°C, add aluminum-titanium-carbon master alloy; Step 6: After the aluminum-titanium-carbon master alloy is completely melted, the molten metal liquid is stirred; Step seven: when the temperature drops to 720°C, the molten metal is cast to obtain a high-strength 6xxx series fine-grained aluminum alloy.

[0019] The present invention adds aluminum-titanium-carbon master alloy, which has high efficiency and time-effectiveness in refinement. It is beneficial to the melt purification of aluminum alloy and improves the metallurgical quality of aluminum alloy products. It can make aluminum alloy ingots obtain grains with uniform size from the surface to the center, and improve the final use performance of the product. It can reduce the intergranular corrosion rate and improve the corrosion resistance of aluminum alloy products. It can effectively overcome refinement "poisoning" and improve the casting quality of high-strength and heat-resistant aluminum alloys. The manufactured high-strength 6xxx series fine-grained aluminum alloy has the following advantages: alloy properties: yield strength ≥430MPa, tensile strength ≥450MPa, elongation ≥10%; grain size: average grain size ≤150μm, maximum grain size ≤300μm.

[0020] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-strength 6xxx series fine-grained aluminum alloy for 3C products, characterized in that: The invention comprises the following weight percentages: Si 0.7-1.2%, Fe≤0.20%, Cu 0.7-1.2%, Mn 0.4-0.8%, Mg 0.8-1.1%, Cr≤0.1%, Zn≤0.25%, Ti≤0.1%, Sc 0.03-0.09% and aluminum-titanium-carbon master alloy 4.65-6.65%, and the balance is aluminum.

2. The high-strength 6xxx series fine-grained aluminum alloy for 3C products according to claim 1, characterized in that: The invention comprises the following weight percentages: Si 1%, Fe 0.20%, Cu 0.7%, Mn 0.5%, Mg 0.8%, Cr 0.1%, Zn 0.25%, Ti 0.1%, Sc0.05% and aluminum-titanium-carbon master alloy 5%, and the balance is aluminum.

3. The high-strength 6xxx series fine-grained aluminum alloy for 3C products according to claim 1, characterized in that: The alloy comprises the following weight percentages: Si 0.7%, Fe 0.1%, Cu 1.0%, Mn 0.6%, Mg 1.1%, Cr 0.05%, Zn 0.15%, Ti0.05%, Sc 0.06% and aluminum-titanium-carbon master alloy 6%, and the balance is aluminum.

4. The high-strength 6xxx series fine-grained aluminum alloy for 3C products according to claim 1, characterized in that: The aluminum-titanium-carbon master alloy includes the following weight percentages: Si≤0.20%, Fe≤0.15%, V≤0.05%, Cr≤0.15%, Ni≤0.15%, Ti4.5-5.5%, C 0.15-0.25%, other individual impurity content <0.10%, total impurity content <0.10%, and the balance is aluminum.

5. A method for manufacturing a high-strength 6xxx series fine-grained aluminum alloy for 3C products according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: weigh pure aluminum, aluminum-titanium-carbon master alloy, other master alloys and refining agents according to a certain proportion and dry them all; Step 2: Place pure aluminum ingots in a smelting furnace and heat until completely melted; Step 3, when the temperature rises to 700-800°C, add other master alloys except the aluminum-titanium-carbon master alloy and wait for them to be completely melted; Step 4: When the temperature reaches 740-760°C, add refining agent to degas and slag; Step 5: When the temperature reaches 740-760°C, add aluminum-titanium-carbon master alloy; Step 6: After the aluminum-titanium-carbon master alloy is completely melted, the molten metal liquid is stirred; Step 7: When the temperature drops to 710-730°C, the molten metal is cast to obtain a high-strength 6xxx series fine-grained aluminum alloy.

6. The method for manufacturing a high-strength 6xxx series fine-grained aluminum alloy for 3C products according to claim 5, characterized in that: In the step 1, other master alloys include: Si 0.7-1.2%, Fe≤0.20%, Cu 0.7-1.2%, Mn 0.4-0.8%, Mg 0.8-1.1%, Cr≤0.1%, Zn≤0.25%, Ti≤0.1%, and Sc 0.03-0.09%.

7. The method for manufacturing a high-strength 6xxx series fine-grained aluminum alloy for 3C products according to claim 5, characterized in that: In the step 1, the components of the refining agent include the following weight percentages: KCl 35-50%, NaCl 30-40%, CaF2 5-8%, Na3AlF6 8-15%, Mg2N3 5-10%, C2Cl6 3-6% and rare earth 0.2-0.5%.