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China’s ‘truly outstanding’ heat-resistant aluminium alloys are 6 times stronger than previous materials

Issued at 2024-05-24



  • Scientists use nanoparticles to supercharge mechanical properties of aluminium alloys
  • Simple, cost-effective process produces alloys that can be easily scaled up for new aerospace, transport applications.
  • A team of Chinese scientists has developed a technique to make aluminium alloys dramatically more heat resistant – overcoming a major obstacle that has limited applications of the lightweight metal that is a crucial component in fields such as aerospace and transport.

    Aluminium alloys are known for their low density, high specific strength, and corrosion resistance. But until now their heat resistance has been relatively limited, with traditional aluminium alloys typically operating at around 350 degrees Celsius (662 Fahrenheit). At temperatures above 400 degrees Celsius, the mechanical properties of these materials quickly deteriorate, which limits their use in aerospace design.

    By adding nanoparticles into ordinary aluminium alloys, scientists from the school of materials science and engineering at Tianjin University (TJU) created a strengthened aluminium alloy that continued to perform well even at much higher temperatures.

  • “This new aluminium alloy has more than six times the strength of traditional aluminium alloys at 500 degrees Celsius, significantly surpassing the best levels reported internationally for aluminium-based materials,” TJU said in an official release earlier this month.

    “This manufacturing process is simple, cost-effective, and easy to scale up for industrial production, making it highly valuable for industrial applications,” lead researcher He Chunnian said in the release.

    “The team is partnering with prominent industry leaders and research institutions to drive forward the development of heat-resistant aluminium alloys for aerospace engines and critical aerospace components, and expects the material to see industrial use soon.”

    The research was published on April 26 in the peer-reviewed journal Nature Materials.

  • The performance improvement in the aluminium alloy was achieved by incorporating highly stable nanometre-sized oxide particles. Aside from their low cost, the particles, which have a melting point above 1,000 degrees Celsius, offer exceptional strength, thermal conductivity, heat resistance, oxidation resistance and corrosion resistance.

    The process of incorporating ceramic particles into alloys to create oxide dispersion-strengthened (ODS) alloys has shown promise. In 2022, Nasa revealed a similar method for producing the nickel-based Nasa Alloy GRX-810, which can withstand 1,093 degrees Celsius.

    According to Nasa’s website, the method significantly improved the strength and durability of components and parts used in aviation and space exploration, resulting in better and longer-lasting performance.

    While ODS alloys have been developed for reducible metals such as iron, molybdenum, nickel and tungsten through chemical processing methods, there have been no commercially available ODS alloys for irreducible metals such as aluminium, magnesium, titanium, and zirconium, because of their high chemical reactivity with oxygen.

    Unlike reducible metals, irreducible metals cannot be easily extracted from their oxide.

    The Chinese research team achieved uniform dispersion of ultra-fine magnesium oxide nanoparticles in aluminium. Image: Handout

    To address the problem, He and his team prepared 5nm magnesium oxide particles and then used powder metallurgy – a manufacturing process for metal parts that compacts and sinters metal powders – to distribute the particles within the aluminium matrix, achieving a volume fraction of 8 per cent.

    “Our strategy achieved ODS aluminium alloys containing highly dispersive 5nm [magnesium oxide] nanoparticles through powder metallurgy,” the researchers said.

    “The material shows truly outstanding properties,” Alexis Deschamps, a renowned international expert in metallic materials from Universite Grenoble Alpes in France, said in a news review by Nature Materials.

    “This development opens new possibilities for the application of aluminium alloys in high-temperature environments, where they could compete with some titanium alloys at a lower weight.”


Source: scmp.com



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