6000 series aluminum alloy with high long-term thermal stability and preparation method thereof

Abstract

The invention provides a 6000 series aluminum alloy with high long-term thermal stability. The alloy comprises the following components of, in percentage by mass, 0.5%-0.8% of Si, less than or equal to 0.3% of Fe, less than or equal to 0.3% of Cu, 0.05%-0.3% of Mn, 0.6%-0.9% of Mg, less than or equal to 0.15% of Zr, less than or equal to 0.15% of Ti, less than or equal to 0.05% of a single impurity, less than or equal to 0.15% of impurities in total, and the balance Al, wherein the range of Si / Mg is controlled at 0.7-0.9. The invention also comprises a preparation method of the aluminum alloy.According to the method, through the alloy design, a long-term thermally stable phase can be generated in the 6000 series alloy, the roughening of an Mg<2>Si phase is effectively inhibited, and the reduction in yield strength is no more than 10 MPa when the alloy is subjected to heat preservation at 150 DEG C for 1000 h. The 6000 series aluminum alloy material not only has the very good long-termthermal stability, but also has the good room temperature mechanical performance, good bending forming performance, crushing performance and the like, and thus the industrial batch production of automobile part profiles can be realized.

Description

technical field [0001] The invention relates to the technical field of aluminum alloy production technology, in particular to a 6000 series aluminum alloy with high long-term thermal stability and a preparation method thereof. Background technique [0002] The 6000 series aluminum alloy is widely used in high-speed rail and automobile fields due to its good mechanical properties and corrosion resistance. With the development of new energy vehicles, the requirements for lightweight vehicles are gradually increasing. As a key lightweight material, aluminum alloy can achieve a weight reduction of more than 30% by replacing traditional steel parts, and is used by major car companies to replace the original steel parts. With the extensive application of aluminum alloys in automobiles, the performance requirements for aluminum alloys are becoming more and more stringent. [0003] In terms of 6000-series aluminum alloy profiles, some car companies have put forward material certif...

AI Technical Summary

Problems solved by technology

For performance requirements such as stretching, bending, crushing, and corrosion resistance, the certification index can also be achieved by fine-tuning the alloy composition and changing the processing technology; however, the long-term thermal stability of the alloy has become a difficult problem for many suppliers. For example, its yield strength can reach more than 300MPa, and it will drop to less than 230MPa after 1000h at 150°C, a decrease of 23%.

[0004] At present, major foreign automobile manufacturers have formulated corresponding standards for the long-term thermal stability of their automotive aluminum alloy products, but my country's aluminum alloy industry has little research on the long-term thermal stability of automotive products.