May 2024 | When designing a mechanical system that includes metal, the engineer’s biggest enemy can be corrosion. The chemical reaction forms rust or causes other kinds of problems, affecting the efficiency or longevity of the device.
A research initiative at Binghamton University’s Thomas J. Watson College of Engineering and Applied Science is set to redefine this notion by turning corrosion into a tool for strengthening metals.
NSF Supports Pioneering 3D Printing Research
Professor Changhong Ke, from the Department of Mechanical Engineering, has been awarded a $150,000 grant from the National Science Foundation’s (NSF) Early-concept Grants for Exploratory Research (EAGER) program. This grant aims to support innovative research ideas that could be game-changers, though they are yet in their early stages.
The focus of Professor Ke’s research is the additive manufacturing of metals, commonly known as 3D printing. While 3D printed metals have revolutionized industries like aerospace, automotive, and marine with their ability to create complex, lightweight structures, they also possess an inherent vulnerability: increased susceptibility to corrosion due to their porosity compared to traditionally manufactured metals.
Ke will investigate the potential of building nanotubes into additively manufactured aluminum. He believes that microscopic structures made of boron nitride – a compound commonly used in cosmetics, pencil lead and cement for dental applications – would make the material self-strengthening under corrosive conditions like moisture and seawater.
“You can’t avoid oxidation, so we are trying to take advantage of it by turning it into a new, reinforcing mechanism to make the material stronger,” Ke said. “People could try to design the materials to include these sorts of porosities or even purposely introducing structures that can be more easily oxidized because it becomes something beneficial instead of harmful to the material itself.”
Incorporating Nanotubes into Metal Structures
The nanotubes threaded throughout the metal are a few nanometers thick, and a few to hundreds of microns long. To see how the oxidation changes the way that nanotubes bind to metal – a core issue in the self-strengthening mechanism, Ke and his team in the Nanomechanics Laboratory will use a force sensor to pull individual nanotubes out of the oxidized metal inside a high-resolution scanning electron microscope, which allows them to watch what is happening in real-time.
“We designed this as a sandwich structure,” he said. “It’s like a hot dog, with the nanotube as the meat and the metal as the bread.”
Additionally, large-scale testing will assess how these changes affect the overall properties of the material, such as stiffness, strength, and toughness. Collaborative efforts with the University of Illinois will supplement these experiments with computational models to validate and expand upon the physical tests.
If successful, this research could pave the way for a new class of materials that use corrosion as a strength-enhancing feature, potentially revitalizing not just the manufacturing sectors in the U.S., but also setting new standards for durability and sustainability in material design worldwide.
