High-strength high-toughness Al-Mg-Si-Cu wrought aluminum alloy and preparation method thereof

Abstract

The invention relates to high-strength high-toughness Al-Mg-Si-Cu wrought aluminum alloy and a preparation method thereof. The alloy comprises the following components in percentage by weight: 0.6-1.5wt% 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; then homogenizing: heating the cast ingot along with a circulating air furnace to 520-570 DEG C, carrying out heat insulation for 4-10 hours, and cooling in air; then carrying out heat processing and heat deformation: carrying out heat processing on the homogenized cast ingot in heat processing equipment, wherein the final heat processing temperature is not lower than 350 DEG C and the strain amount is not lower than 0.5; and finally carrying outheat treatment.

Description

technical field [0001] The invention relates to a high-strength and high-toughness Al-Mg-Si-Cu deformed aluminum alloy 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 deve...

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Problems solved by technology

Studies have shown that in 6××× alloys, the Mg can be increased by increasing the content of Mg and Si 2 The amount of Si strengthening phase can further increase the strength of the alloy, but after increasing to a certain extent, not only the expected strength value cannot be obtained, but also the plasticity and toughness of the material will be seriously reduced.

In addition, 6××× aluminum alloys are prone to recrystallization during forging and solid solution, resulting in coarse grains, resulting in a sharp decrease in mechanical properties

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