Hexagonal OsB₂: New low-cost, ultra-hard ceramic material increases the stability and reliability of cutting tools and machinery parts

UCF researchers have created hexagonal osmium diboride (OsB₂), a new, ultra-hard ceramic compound that, until now, had only existed in the form of a mathematical calculation. With its superior mechanical and functional properties, hexagonal OsB₂ is ideal for use as a protective coating on cutting tools, pistons, turbine blades and other machinery parts. In creating the new composition, researchers also developed a novel, inexpensive and scalable method of producing it via mechanochemical synthesis.

Technical Details

The invention encompasses a composition for hexagonal OsB₂ and a method of producing the new material by mechanochemically reacting osmium and boron powders using a high-energy ball mill. The compound’s hexagonal lattice structure can have a hardness value of 52±4 gigapascals (GPa) and a Young's modulus (stiffness) range of 561±38 GPa to 585±42 GPa. Ultra-incompressible, the compound undergoes negative thermal expansion at temperatures from 300 to 500 C in the direction of the lattice parameter, and it is stable at temperatures from about -223 C to 875 C upon cooling and heating. The mechanochemical synthesis is extremely energy efficient, with the mill consuming only 100 watts of power to produce 10 grams of material.

Benefits

• Harder and more stable than other ceramic materials
• Producible in bulk powder form
• Methodology is scalable and provides significant energy and cost savings over other high-pressure and high-temperature solid-state synthesis methods

Applications

• Wear-resistant and oxidation-resistant coatings for cutting tools, blades and other industrial parts
• Abrasives

Additional UCF ID# 32904