MOLYBDENUM DIBORIDE

Molybdenum diboride is a gray powder with high strength and hardness and has resistance to high temperatures, good electrical conductivity, and good oxidation resistance.

Molybdenum boride, Mo2B, has a specificgravity of 9.3, a Knoop hardness of 1660, anda melting point of about 1660°C. Tungstenboride, W2B, has a specific gravity of 16.7 anda melting point of' 2770°C. Titanium boride,TiB2, is light in weight with a specific gravityof 4.5. It has a melting point at about 2593°C.Molded parts made from the powder have aKnoop hardness of 3300 and a flexural strengthof 241 MPa, and they are resistant to oxidationto 982°C with a very low oxidation rate abovethat point to about 1371°C. They are inert tomolten aluminum. Intermetal powders of beryllium–tantalum, beryllium–zirconium, andberyllium–columbium are also marketed, andthey are lightweight and have high strength.Sintered parts resist oxidation to 1649°C.