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 ...

AI Technical Summary

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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