Click here to sign in with or

by Matthew Chin, University of California, Los Angeles

An aluminum alloy developed in the 1940s has long held promise for use in automobile manufacturing, except for one key obstacle. Although it's nearly as strong as steel and just one-third the weight, it is almost impossible to weld together using the technique commonly used to assemble body panels or engine parts.

That's because when the alloy is heated during welding, its molecular structure creates an uneven flow of its constituent elements—aluminum, zinc, magnesium and copper—which results in cracks along the weld.

Now, engineers at the UCLA Samueli School of Engineering have developed a way to weld the alloy, known as AA 7075. The solution: infusing titanium carbide nanoparticles—particles so small that they're measured in units equal to one billionth of a meter—into AA 7075 welding wires, which are used as the filler material between the pieces being joined. A paper describing the advance was published in Nature Communications.

Using the new approach, the researchers produced welded joints with a tensile strength up to 392 megapascals. (By comparison, an aluminum alloy known as AA 6061 that is widely used in aircraft and automobile parts, has a tensile strength of 186 megapascals in welded joints.) And according to the study, post-welding heat treatments, could further increase the strength of AA 7075 joints, up to 551 megapascals, which is comparable to steel. Graduate student Maximilian Sokoluk; laboratory mechanician Travis Widick, holding a demonstration bike frame welded using aluminum alloy 7075; and Professor Xiaochun Li. Credit: Kenny Stadelmann/UCLA

Because it's strong but light, AA 7075 can help increase a vehicle's fuel and battery efficiency, so it's already often used to form airplane fuselages and wings, where the material is generally joined by bolts or rivets rather than welded. The alloy also has been used for products that don't require joining, such as smartphone frames and rock-climbing carabiners.

But the alloy's resistance to welding, specifically, to the type of welding used in automobile manufacturing, has prevented it from being widely adopted.

"The new technique is just a simple twist, but it could allow widespread use of this high-strength aluminum alloy in mass-produced products like cars or bicycles, where parts are often assembled together," said Xiaochun Li, UCLA's Raytheon Professor of Manufacturing and the study's principal investigator. "Companies could use the same processes and equipment they already have to incorporate this super-strong aluminum alloy into their manufacturing processes, and their products could be lighter and more energy efficient, while still retaining their strength."

The researchers already are working with a bicycle manufacturer on prototype bike frames that would use the alloy; and the new study suggests that nanoparticle-infused filler wires could also make it easier to join other hard-to-weld metals and metal alloys. More information: Maximilian Sokoluk et al. Nanoparticle-enabled phase control for arc welding of unweldable aluminum alloy 7075, Nature Communications (2019). DOI: 10.1038/s41467-018-07989-y Journal information: Nature Communications Provided by University of California, Los Angeles Citation: Nanotechnology enables engineers to weld previously un-weldable aluminum alloy (2019, January 25) retrieved 8 March 2023 from https://phys.org/news/2019-01-nanotechnology-enables-weld-previously-un-weldable.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

More information: Maximilian Sokoluk et al. Nanoparticle-enabled phase control for arc welding of unweldable aluminum alloy 7075, Nature Communications (2019). DOI: 10.1038/s41467-018-07989-y Journal information: Nature Communications

Provided by University of California, Los Angeles

Use this form if you have come across a typo, inaccuracy or would like to send an edit request for the content on this page. For general inquiries, please use our contact form. For general feedback, use the public comments section below (please adhere to guidelines).

Please select the most appropriate category to facilitate processing of your request

Thank you for taking time to provide your feedback to the editors.

Your feedback is important to us. However, we do not guarantee individual replies due to the high volume of messages.

Your email address is used only to let the recipient know who sent the email. Neither your address nor the recipient's address will be used for any other purpose. The information you enter will appear in your e-mail message and is not retained by Phys.org in any form.

Get weekly and/or daily updates delivered to your inbox. You can unsubscribe at any time and we'll never share your details to third parties.

Medical research advances and health news

The latest engineering, electronics and technology advances

The most comprehensive sci-tech news coverage on the web

This site uses cookies to assist with navigation, analyse your use of our services, collect data for ads personalisation and provide content from third parties. By using our site, you acknowledge that you have read and understand our Privacy Policy and Terms of Use.