Self-Healing Metal Coating
Engineers have developed a new coating strategy for metal that self-heals within seconds when scratched, scraped, or cracked. The novel material could prevent these tiny defects from turning into localized corrosion, which can cause significant structures to fail. It’s hard to believe that a tiny crack could take down a gigantic metal structure, but sometimes bridges collapse, pipelines rupture, and fuselages detach from airplanes due to hard-to-detect corrosion in tiny cracks, scratches, and dents.
Localized corrosion is extremely dangerous. It is hard to prevent, hard to predict, and hard to detect, but it can lead to catastrophic failure. Engineering team has developed a new coating strategy for metal that self-heals within seconds when scratched, scraped, or cracked. The novel material could prevent these tiny defects from turning into localized corrosion, which can cause major structures to fail. https://www.glewengineering.com/window-energy-efficiency-solar-heat-gain-and-visible-transmittance/
Wind causes repeated loads to structures. This material coating may help prevent small cracks in structures with exposed metal. https://www.glewengineering.com/comparing-wind-load-calculation-methods/
When damaged by scratches and cracks, the system readily flows and reconnects to heal right before the eyes rapidly. The Engineering Researchers demonstrated that the material could repeatedly heal — even after scratching the same spot nearly 200 times in a row.
Challenges of Self-Healing Materials
While a few self-healing coatings already exist, those systems typically work for nanometer- to micron-sized damages. Huang and his team looked to fluid flow to develop a coating that can heal larger scratches on the millimeter scale. Engineers needed to develop a system with contradicting properties: fluidic enough to flow automatically but not so fluidic that it drips off the metal’s surface. ://glewengineering.com/engineers-help-with-small-business-ventilation/
Engineer Researchers met the challenge by creating a network of lightweight particles, in this case, graphene capsules, to thicken the oil. The network fixes the oil coating, keeping it from dripping. When a crack or scratch damages the network, it actively releases the oil, allowing it to flow and reconnect quickly. The material can be made with any hollow, lightweight particle — not just graphene. The particles essentially immobilize the oil film, so it stays in place. https://www.glewengineering.com/wind-load-cfd-modeling/
The coating not only sticks, but it sticks well — even underwater and in harsh chemical environments, such as acid baths. Huang imagines it could be painted onto bridges and boats naturally submerged underwater and metal structures near leaked or spilled highly corrosive fluids. The coating can 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 pinholes and corrosion.
Read more about Fluid Inspired Material Coating for Metals: https://www.spacedaily.com/reports/Fluid_inspired_material_self_heals_before_your_eyes_999.html