"And those fumes have to be collected and scrubbed of all chromium through a regulated ventilation system," he noted. "Chrome plating, along with most other plating operations, introduces elemental hydrogen into the steel, which leads to a phenomenon known as hydrogen embrittlement."
Olmstead said that if the hydrogen is left in high strength steel parts, which makes up most landing gear parts, it will cause the steel to lose its expected strength and could lead to catastrophic failure if left unchecked.
To prevent that from happening, parts are baked for various times anywhere from four to 24 hours at 375 degrees Fahrenheit to ensure all induced hydrogen is baked out.
He said, while the current high velocity oxygen fuel system uses powders consisting of tungsten, cobalt, chromium and carbides, they're in their metallic form when fed into the combustion chamber and return to their metallic form upon cooling, so only the dust generated needs to be collected and filtered.
"This is much safer and easier to control than plating fumes," Olmstead said. "Simply put, high velocity oxygen fuel reduces the exposure and use of hazardous chemicals."
"And we're able to replace chrome with a coating that is more durable and gives better wear-ability, which reduces overhaul costs and extends part life," he explained. "It's also easier for mechanics to use."
By being able to create powders with metal and non-metal compounds, the coating can be engineered to produce the qualities maintainers are looking for - wear resistance, corrosion protection, ductility, and other desirable metallurgical properties.
It's also non-hydrogen embrittling, which eliminates risks and reduces the time it takes to process parts by reducing required bakes.
"Field tests have shown superior results compared to chrome plating," said Olmstead. "And we'll save in longer lasting parts needing less future overhaul repairs and savings in environmental costs associated with chrome plating."