It`s magic

A Northwestern University team has developed a new coating strategy for metal that self-heals within seconds when scratched, scraped or cracked.

Jiaxing Huang

The novel material could prevent defects from turning into localized corrosion, which can cause major structures to fail. “Localized corrosion is extremely dangerous,” said Jiaxing Huang professor of material science and engineering in Northwestern`s McCormick School of Engineering, who led the research. “It is hard to prevent, hard to predict and hard to detect, but it can lead to catastrophic failure.” When damaged by scratches and cracks, Huang’s patent-pending system flows and reconnects to rapidly heal right before the eyes. The researchers demonstrated that the material can heal repeatedly — even after scratching the exact same spot nearly 200 times in a row. The corresponding study was published on 28th of January.
While a few self-healing coatings already exist, those systems typically work for nanometer- to micron-sized damages. To develop a coating that can heal larger scratches in the millimeter-scale, Huang and his team looked to fluids, more precisely oils. The research team developed a system with contradicting properties: fluidic enough to flow automatically but not so fluidic that it drips off the metal’s surface. They created a network of lightweight particles — in this case graphene capsules — to thicken the oil. The network fixes the oil coating, keeping it from dripping. But when the network is damaged by a crack or scratch, it releases the oil to flow readily and reconnect. Huang said the material can be made with any hollow, lightweight particle — not just graphene.
The coating sticks even underwater and in harsh chemical environments, such as acid baths. The coating can also withstand strong turbulence and stick to sharp corners without budging. When brushed onto a surface from underwater, the coating goes on evenly without trapping tiny bubbles of air or moisture that often lead to pin holes and corrosion.

Further information:

Hersteller zu diesem Thema

Subscribe to our international Newsletter!