High-strength Al-Mg-Si-Cu alloy and preparation method thereof

Abstract

The invention relates to high-strength Al-Mg-Si-Cu alloy and a preparation method thereof. The alloy comprises 0.8-1.4wt% of Mg, 0.8-1.6wt% of Si, 0.2-0.8wt% of Cu, 0.2-1.0wt% of Mn, 0.1-0.4wt% of Cr, 0.01-0.1wt% of Ti, not more than 0.25wt% of Fe, not more than 0.15wt% of all inevitable impurities and the balance of Al. The preparation method of the alloy comprises the following steps of: preparing an alloy cast ingot by adopting a semi-continuous casting mode, heating the semi-continuous cast ingot along with the furnace to 300-350 DEG C, then heating to 520-570 DEG C at a heating rate of 1-10 DEG C / min, carrying out heat insulation for 4-10 hours, cooling in air, heating the homogenized cast ingot again to 450-500 DEG C, and forging, wherein the final forging temperature is not lower than 350 DEG C; and carrying out T6 heat treatment on the forged piece.

Description

technical field

[0001] The invention relates to a high-strength Al-Mg-Si-Cu alloy forging material and a preparation method thereof, belonging to the technical field of nonferrous metals. Background technique

[0002] The general development trend of the world's transportation vehicles is lightweight, in order to achieve the purpose of saving energy, reducing consumption and reducing pollution. Over the years, aluminum has gradually replaced steel in automobiles due to its many unique properties, good formability and low production costs, and has become one of the important materials to promote the lightweight of automobiles.

[0003] Compared with traditional cast iron materials, the use of aluminum alloy forgings to produce auto parts can not only greatly reduce the weight, greatly improve the strength, toughness and ductility, but also enable the materials to obtain reliable internal quality and excellent comprehensive performance. Therefore, the development of aluminum ...

Examples

Embodiment Construction

[0018] High-strength Al-Mg-Si-Cu alloy, the mass percentage of the composition is: Mg 0.8~1.4wt.%, Si 0.8~1.6wt.%, Cu 0.2~0.8wt.%, Mn 0.2~1.0wt.% , Cr 0.1~0.4wt.%, Ti 0.01~0.1wt.%, Fe≤0.25wt.%, the sum of unavoidable impurities ≤0.15wt.%, and the balance is Al. The as-cast grain size of the alloy is less than 130 μm, the secondary dendrite arm spacing is not more than 40 μm, the grain size of the T6 state is less than 15 μm, the yield strength of the material is above 370 MPa, and the elongation is greater than 12%.

[0019] Mg and Si are the main alloying elements in the 6××× series aluminum alloys, forming the main strengthening phase Mg of the alloy 2 Si. This series of alloys improves the material strength by controlling the Mg / Si ratio and excess Si content. When the Mg and Si content is too low, the Mg 2 The amount of Si strengthening phase is small, and the strength of the material is low; when the content of Mg and Si is too high, on the one hand, the formability of ...

technical field

[0001] The invention relates to a high-strength Al-Mg-Si-Cu alloy forging material and a preparation method thereof, belonging to the technical field of nonferrous metals. Background technique

[0002] The general development trend of the world's transportation vehicles is lightweight, in order to achieve the purpose of saving energy, reducing consumption and reducing pollution. Over the years, aluminum has gradually replaced steel in automobiles due to its many unique properties, good formability and low production costs, and has become one of the important materials to promote the lightweight of automobiles.

[0003] Compared with traditional cast iron materials, the use of aluminum alloy forgings to produce auto parts can not only greatly reduce the weight, greatly improve the strength, toughness and ductility, but also enable the materials to obtain reliable internal quality and excellent comprehensive performance. Therefore, the development of aluminum ...

Examples

Embodiment Construction

[0018] High-strength Al-Mg-Si-Cu alloy, the mass percentage of the composition is: Mg 0.8~1.4wt.%, Si 0.8~1.6wt.%, Cu 0.2~0.8wt.%, Mn 0.2~1.0wt.% , Cr 0.1~0.4wt.%, Ti 0.01~0.1wt.%, Fe≤0.25wt.%, the sum of unavoidable impurities ≤0.15wt.%, and the balance is Al. The as-cast grain size of the alloy is less than 130 μm, the secondary dendrite arm spacing is not more than 40 μm, the grain size of the T6 state is less than 15 μm, the yield strength of the material is above 370 MPa, and the elongation is greater than 12%.

[0019] Mg and Si are the main alloying elements in the 6××× series aluminum alloys, forming the main strengthening phase Mg of the alloy 2 Si. This series of alloys improves the material strength by controlling the Mg / Si ratio and excess Si content. When the Mg and Si content is too low, the Mg 2 The amount of Si strengthening phase is small, and the strength of the material is low; when the content of Mg and Si is too high, on the one hand, the formability of ...

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