A kind of 7 series aluminum alloy and preparation method thereof

Abstract

The invention discloses a 7-series aluminum alloy, which belongs to the technical field of aluminum alloys. The 7-series aluminum alloy is composed of the following components in weight percentage: 5.9-6.25% of zinc, 2-2.3% of magnesium, 0.12-0.26% of Copper, 0.12‑0.24% manganese, 0.01‑0.07% silicon, 0.008‑0.023% titanium, 0.0001‑0.007% chromium, 0.005‑0.03% zirconium, 0.01‑0.12% iron, and the balance aluminum. The 7-series aluminum alloy provided by the present invention effectively improves the mechanical properties of the obtained 7-series aluminum alloy by precisely controlling the content of Mg and Zn, controlling the ratio of the two, and at the same time reducing the copper content to a certain extent. The tensile strength of the alloy can reach more than 490MPa, the yield strength is more than 480MPa, and the Vickers hardness HV can reach more than 170, which provides the possibility and guarantee for the development and production of high-performance new products.

Description

technical field

[0001] The invention belongs to the technical field of aluminum alloys, and in particular relates to a 7-series aluminum alloy and a preparation method thereof. Background technique

[0002] Aluminum alloy is a light metal material with good casting performance, plastic processing performance, electrical conductivity, thermal conductivity, and good corrosion resistance and weldability. Aluminum alloys can be used as structural materials and are widely used in aerospace, aviation, transportation, construction, electromechanical, light chemical and daily necessities. According to the different proportions of the raw materials, aluminum alloys can be divided into 1-7 series, and the mechanical properties of different series of aluminum alloys also have a large gap. The 7-series aluminum alloy is also called Al-Zn-Mg-Cu alloy, and the 7-series aluminum alloy has the characteristics of low density and high strength. At present, the tensile strength of the 7 seri...

Examples

preparation example Construction

[0033] A method for preparing the above-mentioned 7-series aluminum alloy of the present invention comprises the following steps: mixing the raw materials uniformly in proportion, followed by melting, refining, slag removal, alloying, casting, homogenization, extrusion, quenching and cooling , to get 7 series aluminum alloy.

[0034] Further, the homogenization is stepwise homogenization heat treatment, the stepwise homogenization heat treatment is composed of the first section, the second section and the third section, the temperature from the first section to the third section increases step by step, and the temperature difference is 100 -130°C.

[0035] It can be seen from the above description that the three-stage homogenization heat treatment can effectively refine the grains and make the grain distribution more uniform.

Embodiment 1

[0037] A 7-series aluminum alloy consisting of the following components in weight percentage: 6.04% Zn, 2.1% Mg, 0.16% Cu, 0.206% Mn, 0.032% Si, 0.0103% Ti, 0.0028% Cr , 0.015% Zr, 0.068% Fe, 0.008% Ni, 0.005% V, 0.001% Pb, 0.0003% Na, 0.00083% B, 0.0103% Ga, 0.001% Cd, and the balance aluminum.

[0038] The preparation method of the above-mentioned 7 series aluminum alloy specifically comprises the following steps:

[0039]Step 1. Select high-purity aluminum ingots with Fe<0.08, Si<0.03, and scraps that meet the composition requirements, and put them into the furnace according to the ratio of high-purity aluminum ingots and scraps at a ratio of 7:3. After rapid melting (500 ° C), stirring , alloying to obtain a uniform melt A; wherein, adding a rare earth alloy during the alloying process;

[0040] Step 2, refining the melt A obtained in step 1, removing slag, standing, and purifying, then transferring it to a holding furnace to obtain melt B;

[0041] Step 3. Refining the...

Embodiment 2

[0061] A 7-series aluminum alloy consisting of the following components in weight percentage: 5.9% Zn, 2.08% Mg, 0.26% Cu, 0.22% Mn, 0.02% Si, 0.015% Ti, 0.004% Cr , 0.018% of Zr, 0.05% of Fe, 0.007% of Ni, 0.003% of V, 0.002% of Pb, 0.0003% of Na, 0.00075% of B, 0.012% of Ga, 0.001% of Cd, and the balance aluminum;

[0062] The preparation method of the above-mentioned 7 series aluminum alloy is the same as that in Example 1.

technical field

[0001] The invention belongs to the technical field of aluminum alloys, and in particular relates to a 7-series aluminum alloy and a preparation method thereof. Background technique

[0002] Aluminum alloy is a light metal material with good casting performance, plastic processing performance, electrical conductivity, thermal conductivity, and good corrosion resistance and weldability. Aluminum alloys can be used as structural materials and are widely used in aerospace, aviation, transportation, construction, electromechanical, light chemical and daily necessities. According to the different proportions of the raw materials, aluminum alloys can be divided into 1-7 series, and the mechanical properties of different series of aluminum alloys also have a large gap. The 7-series aluminum alloy is also called Al-Zn-Mg-Cu alloy, and the 7-series aluminum alloy has the characteristics of low density and high strength. At present, the tensile strength of the 7 seri...

Examples

preparation example Construction

[0033] A method for preparing the above-mentioned 7-series aluminum alloy of the present invention comprises the following steps: mixing the raw materials uniformly in proportion, followed by melting, refining, slag removal, alloying, casting, homogenization, extrusion, quenching and cooling , to get 7 series aluminum alloy.

[0034] Further, the homogenization is stepwise homogenization heat treatment, the stepwise homogenization heat treatment is composed of the first section, the second section and the third section, the temperature from the first section to the third section increases step by step, and the temperature difference is 100 -130°C.

[0035] It can be seen from the above description that the three-stage homogenization heat treatment can effectively refine the grains and make the grain distribution more uniform.

Embodiment 1

[0037] A 7-series aluminum alloy consisting of the following components in weight percentage: 6.04% Zn, 2.1% Mg, 0.16% Cu, 0.206% Mn, 0.032% Si, 0.0103% Ti, 0.0028% Cr , 0.015% Zr, 0.068% Fe, 0.008% Ni, 0.005% V, 0.001% Pb, 0.0003% Na, 0.00083% B, 0.0103% Ga, 0.001% Cd, and the balance aluminum.

[0038] The preparation method of the above-mentioned 7 series aluminum alloy specifically comprises the following steps:

[0039]Step 1. Select high-purity aluminum ingots with Fe<0.08, Si<0.03, and scraps that meet the composition requirements, and put them into the furnace according to the ratio of high-purity aluminum ingots and scraps at a ratio of 7:3. After rapid melting (500 ° C), stirring , alloying to obtain a uniform melt A; wherein, adding a rare earth alloy during the alloying process;

[0040] Step 2, refining the melt A obtained in step 1, removing slag, standing, and purifying, then transferring it to a holding furnace to obtain melt B;

[0041] Step 3. Refining the...

Embodiment 2

[0061] A 7-series aluminum alloy consisting of the following components in weight percentage: 5.9% Zn, 2.08% Mg, 0.26% Cu, 0.22% Mn, 0.02% Si, 0.015% Ti, 0.004% Cr , 0.018% of Zr, 0.05% of Fe, 0.007% of Ni, 0.003% of V, 0.002% of Pb, 0.0003% of Na, 0.00075% of B, 0.012% of Ga, 0.001% of Cd, and the balance aluminum;

[0062] The preparation method of the above-mentioned 7 series aluminum alloy is the same as that in Example 1.

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