Tianjin University has developed a super-strong aluminum alloy capable of withstanding 500°C

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　　According to Sinochem New Network, recently, a team led by Professor He Chunnian from the School of Materials at Tianjin University developed an oxide-dispersed strengthened aluminum alloy, which raises the operating temperature of such alloys to 500°C, thereby overcoming the challenge of using aluminum alloys in high-temperature environments above 400°C. The relevant research findings were published in Nature Materials. 　　He Chunnian stated that oxide-dispersed strengthening alloys possess high thermal stability and mechanical properties at high temperatures. However, at present, such alloys are mainly prepared by chemical methods such as internal oxidation or metal matrix reduction, and are not suitable for lightweight metals that cannot be chemically reduced, such as aluminum, titanium, and magnesium. How to achieve dispersion strengthening of nanoscale oxides in aluminum alloys in order to improve their mechanical properties at high temperatures is an international scientific and technical challenge for aluminum alloys and lightweight alloy systems as a whole. 　　In this research, He Chunnian’s team prepared 5-nanometer oxide-dispersed strengthened aluminum alloys using an \"interface displacement\" dispersion strategy, which retained extremely high tensile strength and resistance to high-temperature creep even at temperatures as high as 500°C. They first prepared ultrafine oxide particles coated with few layers of graphite by utilizing the self-assembly effect during the decomposition of metal salt precursors; the strong chemical bonds between the nanoparticles were replaced by weaker van der Waals forces between the graphite coating layers, thereby reducing the adhesion between the nanoparticles by 2 to 3 orders of magnitude. On this basis, they further achieved uniform dispersion of single-particle-level ultra-fine oxide particles with a high volume fraction within the aluminum matrix through a simple mechanical ball-milling/powder metallurgy process, enabling the aluminum alloy to exhibit outstanding high-temperature mechanical properties and resistance to high-temperature creep, far exceeding the best levels of aluminum-based materials reported internationally. In addition, this preparation process also has advantages such as a simple procedure, low material costs, and ease of scale-up production. 　　Industry experts believe that this research has developed new strategies for designing alloys strengthened by ultra-fine nanoscale oxides, and has revealed the mechanisms by which ultra-fine nanoparticles enhance the exceptional heat resistance of lightweight metals. It provides new approaches for developing heat-resistant, high-strength lightweight metal materials and their application in important fields such as aerospace and transportation.