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There is good potential for MoAlB-not just as a coating but as a bulk material.
BORIDES ARE TYPICALLY PREPARED FROM BORON AND A METAL. They are typically ultra-high melting point solids that display exceptional hardness in combination with good mechanical, electronic and thermal characteristics.
The primary use for borides is as metal surface coatings because their range of properties enables them to protect materials operating under such severe conditions as internal combustion engines and cutting tools.
In a past TLT article, a more efficient process for applying boride coatings onto metal surfaces was described.1 A very dense, iron (III) boride coating that has a thickness over 90 microns can be applied in only 30 minutes at a temperature ranging between 770 C and 950 C.
This much more energy efficient and environmentally friendly process is known as ultra-fast boriding. Coating 9310 gear steel using this process led to superior coefficient of friction and wear reduction compared to carburized steel.
But use of borides is restricted due to their tendency to readily oxidize at high temperatures. Michel W Barsoum, Distinguished professor of materials science and engineering at Drexel University in Philadelphia, says, "Borides operate very effectively at high temperatures (defined as temperatures above 1,000 C) and can provide a protective coating to metals. But borides are vulnerable to oxidation when placed in an oxygen-rich, high-temperature environment. This makes them unsuitable for applications such as hypersonic flight and jet engine turbine blades."
Barsoum...