Sources/Uses
Nitrides rarely occur in nature. Transition-metal nitrides were first used in the early 20th century for their "hardness, high melting point, metallic luster, and superconductivity." The nitrides of the alkaline-earth metals (beryllium, strontium, barium, magnesium, and calcium) are used as sintering additives; Transition-metal nitrides (titanium, zirconium, and hafnium) are used to reduce wear in steel and hard-metal cutting tools. In case hardening, nitrogen is added to a metallic surface by ammonia, plasma, or salt-bath nitriding to make a thin layer of Fe3N, Fe4N, VN, Cr2N, CrN, Ni3(C,N), Mn4N, or Co3N. Aluminum nitride is used in electronics, dental alloys, and bullet-proof vests. Gallium nitride is used as a light-emitting diode (LED). Silicon nitride is used in semiconductor components and in high-temperature ball bearings, dies, automotive engine parts, pressure valves, and cutting tools. [Ullmann]
Comments
Nitrides are one of the four binary salts that have specific hazards (nitrides, carbides, hydrides, and phosphides); Nitrides give off ammonia, and a corrosive base is formed from contact with water. The corrosive base is the hydroxide of the metal that is attached to the nitrogen in the nitride compounds; [Burke, p. 21]