A newly made surface coating for steel can make it stronger and more resistant to rust and corrosion, according to its developers.
Scientists from Harvard's John A. Paulson School of Engineering and Applied Sciences (SEAS) were able to create a surface coating for steel that not only repels corrosion but also makes the metal stronger.
"Our (coating material) is...more durable than any anti-fouling material that has been developed before," said Joanna Aizenberg, a core member of the Wyss Institute for Biologically Inspired Engineering at Harvard University.
Aizenberg and her team developed a new surface coating made from rough, nanoporous tungsten oxide. It was found to be the most durable, anti-corrosive and anti-fouling coating material to date, tried and tested to resist rust and repel any kind of liquid even after the coated metal has sustained considerable structural damage.
The team tested the coating's durability by scratching with stainless steel tweezers, diamond-tipped scribers, screwdrivers and beating it hard, heavy beads.
Anti-wetting properties were tested by soaking the metals on various liquids like oil, water, blood and corrosive chemicals.
The coating not only withstood all these tests but was also found to make steel stronger compared to the uncoated ones.
The researchers said that the concept of combining durability and anti-fouling properties in a coating was not as successfully made into reality until now, because rough texture often required to resist fouling makes coated metals weaker.
The team made this possible by making an ultrathin film of thousands of small tungsten oxide islands to directly coat the steel surface. If one part of one island is destroyed, the damage does not spread to the other islands due to the lack of connection among them. This helps the coating retain its repelling properties while helping the steel improve its durability.
Aizenberg said that the team's success proved that careful surface engineering is capable of combining two conflicting functions to work together in a way that doesn't hinder each other's performances.
The coating material had potential to be used on different industrial and commercial applications like non-fouling medical devices and tools, 3-D printers, large scale use on buildings and on marine vessels or vehicles. The beneficial properties the coating provided could save industries millions in production and maintenance costs.
"This research is an example of hard core, classic material science," said Aizenberg. "We took a material that changed the world and asked, how can we make it better?"
