New surface coating makes steel more reliable, safer and stronger

Researchers at the John A. Paulson Harvard School of Engineering and Applied Sciences (SEAS) have developed a new surface coating that can make steel safer, safer, and stronger. This was announced by the World Steel Association Worldsteel on Tuesday.

The coating, made of tough nanoporous tungsten oxide, is the most durable anti-corrosion material to date, able to keep steel from any existing fluids, even in the event of significant damage to the surface of the part. In addition, this coating has anti-fouling properties, which allows it to be used without staining in underwater parts, for example, on the bottoms of marine vessels.

The team of materials science professor Joanne Eisenberg pioneered sliding moisture-reflective porous surfaces in 2011 and has been showing a wide range of developments in this area since then. The new product is described in Nature Communications.

“Our steel is orders of magnitude stronger than any anti-fouling material that has been developed before,” said Eisenberg. “So far, these two concepts - mechanical strength and anti-fouling - have been opposed to each other. New research shows that we have engineered material to perform somewhat conflicting functions without compromising performance. ”

The biggest challenge in getting a new surface was to figure out how the steel structure keeps the growth of microorganisms and algae in check without mechanical damage. The team solved this using electrochemical techniques by growing an ultra-thin film of hundreds of thousands of tungsten oxide islands directly on the steel surface.

“If one part of the tungsten island is destroyed, the damage does not spread to other parts of the surface due to the lack of connectivity between neighboring islands,” said Alexander B. Tesler, a former SEAS researcher. "This isolated island principle, combined with the toughness and roughness of tungsten oxide, allows the surface to retain surface properties after abrasion, which has not been possible until now."

The new materials can find very wide applications, including in medical instruments and devices such as implants and scalpels, in nozzles for 3-D printers, and possibly in the construction of buildings and ships.

While many grades of steel have been developed over the past 50 years, steel surfaces have remained largely unchanged. “This study is an example of classical materials science,” said Eisenberg. "We took the material that changed the world and asked how we can make it better?"

New research work