Researchers Develop ‘Armor’ Coatings for Steel

TUESDAY, JANUARY 30, 2024


Scientists at the Oak Ridge National Laboratory are reportedly studying how hexagonal boron nitride coatings on metal alloys can improve durability, decrease friction and protect against harsh conditions.

A release from the laboratory states that the hBN coating, also referred to by the team as “armor,” is made from a combination of solid boron sources and molecular nitrogen through atmospheric pressure chemical vapor deposition.

About the Research

The team reportedly found that stainless steel and other metal alloys coated with hBN have shown non-stick or low-friction qualities with strong long-term protection against corrosion and high-temperature oxidation in air.

The release adds that metal alloys are created to be strong, durable and resistant to corrosion or oxidation. Researchers stated that adding coatings to make those materials even tougher could enhance existing products and enable the creation of new ones.

According to a report from SciTech Daily, the research aims to improve the performance and durability of solar panels, semiconductors and aerospace components.

The report states that coatings may boost the ability of solar panels to conduct heat and resist environmental factors, also allowing semiconductors to keep proper operating temperature.

Additionally, this is expected to help aerospace turbine blades guard against wear, reduce friction and withstand hot conditions.

The hBN coatings are reportedly created from a combination of solid boron sources and molecular nitrogen through a process called atmospheric pressure chemical vapor deposition.

“This synthesis technique addresses scalability issues such as cost and process safety in applications where those aspects have been problematic,” said ORNL’s Ivan Vlassiouk, who led the study.

“Besides providing a versatile protective layer for steels and metals, using this process to synthesize single- and few-layer hBN for emerging two-dimensional electronic and photonic devices could improve their performance.”

The study was published in the journal Advanced Materials.

More Steel Coatings

In April 2023, researchers from Sandia National Laboratories reportedly tested a variety of nickel mixtures as protective coatings on stainless steel to protect it from corrosion caused by sea air. One such problem that could reportedly benefit from the research includes the use of stainless-steel canisters that store spent nuclear fuel in coastal areas.

The results of the study were recently published in the scientific journal Frontiers in Metals and Alloys. The work was supported by the Department of Energy’s Office of Nuclear Engineering.

According to the lab’s release, the researchers found that the specific material applied, and the specific application process used, impacted the properties of the coating, including how protective it was against corrosion.

Nuclear fuel rods that no longer produce enough heat for a nuclear power plant are transferred to a pool of water at a reactor site and, after several years, the spent nuclear fuel is then placed inside a stainless-steel canister. These dry storage canisters are highly radioactive, with stress corrosion cracking posing a potential risk in aging canisters.

As a result, Sandia collaborators at the Electric Power Research Institute began working with nuclear power plant operators to analyze samples inside the canisters. Bryan said that they found chloride salts in every sample.

Sandia researchers also carried out a large experiment to ascertain if the welds used to manufacture the dry storage canisters produced enough stress to allow stress corrosion cracking to occur, Bryan said. They found that the welds do produce enough stress.

Sandia reports that it was found that the gas used to spray on the metal particles had a strong impact on how porous, or spongy, the coating was. The porosity of the coating greatly impacted the corrosion behavior of the coating.

Also, earlier this month, a team of researchers published a study on the use of eggshells in anticorrosive coatings for steel due to their unique chemical composition and wide availability.

The study was published in the journal Progress in Organic Coatings and covered the use of chemically and thermally treated eggshell nanoparticles as fillers. The nanoparticles were reportedly used as a part of a zinc-rich epoxy matrix for a mild steel in sodium chloride solution.

According to the team, the global cost of corrosion was reportedly around $2.5 trillion, equal to 3.4% of the world's Gross Domestic Product in 2016. Unmitigated corrosion can also reportedly cost about $500 billion a year in the United States. On top of this financial consequence, corrosion can create environmental risks, including toxicity to humans and animals when heavy metals leak into the environment during the corrosion process.

According to the researchers, organic coatings can give solid physical barrier protection to metals in corrosive environments, while the incorporation of nanofillers can improve the barrier protection and cathodic effect of the epoxy zinc-based organic coatings, improving the anticorrosion performance.

Eggshells are reportedly made up of 95% calcium carbonate (CaCO3) and 5% protein materials like X collagen, and sulfated polysaccharides. The heavy content of CaCO3 from eggshell waste has reportedly provided a separate source of CaCO3 from the demand for conventional CaCO3 from limestone by cement industries.

In one part of the study, the team electroplated eggshell waste particles and zinc on a mild steel substrate for corrosion protection by electroplating a solution made from zinc chloride (ZnCl2), potassium chloride (KCl), boric acid, thiourea and multiple compositions of eggshell particles.

As a result, scientists reported that the coated substrate showed good anticorrosion performance in saline environments.

The team also reportedly used CaCO3 from calcite ore, marble and eggshell waste, putting it into an epoxy matrix to make an epoxy-based zinc ferrite paint and deploying it in corrosion protection of reinforced concrete rods. The result reportedly showed strong corrosion protection performance.

According to the team, the research showed how the sustainable use of eggshell nanoparticle can be built from chemically treated eggshell wastes and help to improve the anticorrosive qualities of zinc-rich epoxy coatings in elevated-temperature maritime environments.

The researchers explained that they took three samples of zinc-rich coatings containing chemically and thermally treated eggshell nanoparticles that were built to create ZENE coatings.

   

Tagged categories: Asia Pacific; Coating Materials; Coating Materials; Coatings; Coatings Technology; Corrosion; Corrosion protection; EMEA (Europe, Middle East and Africa); Environmental Control; Environmental Protection; Latin America; Metal coatings; Metallic coatings; North America; Program/Project Management; Protective Coatings; Research; Research and development; Steel; Z-Continents

Join the Conversation:

Sign in to our community to add your comments.