Evolution of High-Temperature Aluminum Alloys: Innovations from MIT and US Laboratories
Recent news has shown that a team of researchers from MIT (Massachusetts Institute of Technology) has developed a new aluminum alloy made using powder metallurgy, capable of high mechanical strength, up to nearly 400 MPa at room temperature, and capable of maintaining good properties up to over 400°C, thus offering very high metallurgical performance.
The study, published in the journal Advanced Materials, details the alloy's design process, which also involved researchers from Paderborn University (Germany) and Carnegie Mellon University.
MIT's New Aluminum Alloy: Characteristics and Applications
According to Professor Mohadeseh Taheri-Mousavi, project leader at MIT and now an assistant professor at Carnegie Mellon University, and Professor John Hart, director of the Department of Mechanical Engineering at the university, this exceptional result opens up numerous opportunities for new applications of the lightweight metal in strategic sectors.
MIT's new aluminum alloy could revolutionize the aerospace, automotive, and structural industries. For example, researchers predict it will enable the creation of critical components that are lighter and more resistant to high temperatures, such as jet engine turbine blades.
Currently, blades are made of titanium, a material more than 50% heavier and up to 10 times more expensive than aluminum, or of advanced composite materials. Concepts echoed by Professor Xinghang Zhang, of the School of Materials Engineering at Purdue University (Indiana, USA), who reiterated that the new alloy could revolutionize the entire industry, especially the automotive and aerospace sectors.
The Development Process: AI and Advanced Engineering
The new lightweight alloy was developed using the most advanced tools currently available in metallurgy, such as artificial intelligence and the most sophisticated engineering techniques, to select the most suitable chemical composition from among the possible variations in terms of alloy components and suitable production methods.
To achieve the most suitable microstructural objectives to ensure the expected performance characteristics, laser bombardment of the base metal with silicon dioxide particles was used. This technique, by introducing "distortions and defects" in the basic crystalline geometry—we're talking about microstructural variations on the order of nanometers, or millionths of a millimeter—ensures higher mechanical strength both at room temperature and at high temperatures.
It's clear that behind all this lies the significant growth in recent decades in metallurgical knowledge of materials and the new instrumental tools available, opportunities that further solidify aluminum's image as the material of the coming decades: not only lightweight, widely available, transformable, and recyclable, but also highly mechanically strong.
The evolution of high-temperature aluminum alloys therefore represents a strategic field of research for expanding the applications of this lightweight metal in contexts previously precluded by the thermal limitations of traditional alloys.
From Scrap to Extrusions: The New ShAPE™ Technology
Another important new result in metallurgical research on light metals has been achieved by scientists at the Pacific Northwest National Laboratory (PNNL) in the United States. This revolutionary process involves a new technique for transforming aluminum scrap directly into solid-state alloy, without any foundry treatments, without melting.
The new technique, called Shear Assisted Processing and Extrusion (ShAPE™), was developed for the production of extrusions using billets made through the solid-phase alloying process.
How the ShAPE™ Process Works
The process uses a high-speed rotating die that disperses crushed aluminum scrap and the appropriate doses of typical alloying elements such as silicon, copper, zinc, and magnesium, generating the heat needed to soften the material through friction and facilitate its extrusion into tubes, bars, and profiles.
Spiral grooves on the surface of the rotating die convey the material toward the extrusion hole. As a result, the simultaneous linear and rotational forces use only 10% of the force normally required to push the material through the die in conventional extrusion processes.
Furthermore, the ShAPE™ process enables the extrusion of alloys that cannot be easily extruded with traditional techniques. The method has been patented and proposed as a new opportunity to transform aluminum scrap into a high-strength alloy in a fraction of the time required by melting, casting, and extrusion.
Implications for Lightweight Alloys in Automotive and Aeronautics
Both of the innovations described represent significant steps in expanding the application possibilities of lightweight alloys for automotive and aeronautics. The MIT alloy, with its high-temperature resistance, opens up new possibilities for high-thermal performance engine and structural components. The ShAPE™ process, for its part, offers a sustainable and cost-effective way to produce high-strength alloys directly from scrap, strengthening the circularity of the aluminum supply chain.
This research confirms how the evolution of high-temperature aluminum alloys and the development of innovative production processes are redefining the application scope of this lightweight metal, positioning it as a strategic material for the technological challenges of the coming decades in the automotive and aeronautics sectors.
Source: A&L Aluminium Alloys Pressure Diecasting Foundry Techniques