Tungsten Carbide: Its Amazing, Useful Properties

Discovered in 1781 by chemical researcher and apothecary Carl William Scheele, tungsten carbide did not gain notoriety until the 1920s, when Osram, a German electrical bulb company, rediscovered its practical applications while searching for alternatives to expensive diamond-drawing dyes (ITIA).

According to the International Tungsten Industry Association, annual world tungsten carbide consumption has jumped from a mere ten tons per year in thge 1930s to 30,000 tons a year in recent years. In a rapidly developing technological world, tungsten carbide's amazing properties of strength and resistance combined with its relative low cost compared to materials previously used to perform work done by tungsten carbide, this practical and aesthetic metal is serving new purposes every day but without the spotlight it deserves.

Tungsten Carbide is rated at a 9 on the Mohs hardness scale with diamonds at 10, and only ultrahard fullerite and newly created aggregated diamond nanorods harder than diamonds. While aggregated diamond nanorods are thought to be the strongest material in the world yet known to man, tungsten carbide was until the discovery of nanorods in 2005 the strongest metal known to man.

For household, industrial, and even many high tech uses, its availability and wear-resistance make tungsten carbide a money-saving upgrade from other materials. Its compressive strength is the highest of all known forged metals and alloys and tungsten carbide does not undergo phase changes under heating and cooling. No heat treating is required for tungsten carbide used in industry as it retains the exact same properties (including the same level of impact resistance) in temperatures ranging from -453°F to oxidizing temperatures of 1000°F and non-oxidizing temperatures of 1500°F. It is 2-3 times as rigid as steel and wears 100 times longer than steel in abrasion, erosion, and galling. Depending on grade, tungsten carbide can have corrosion-wear resistance comparable with noble metals. Its high heat, impact, and wear resistance means that in industrial uses, tungsten carbide will retain a higher level of precision than most metals for a longer time. However, tungsten carbide's strength and resistance is partly contributed to its density; it is 1 to 1.5 times heavier than carbon steel. (ITIA)

Still, tungsten carbide can be found in use in mines, manufacturers, and even jewelers. An array of tungsten carbide products is available: wear parts, cutting tools, mining tools, high tech tools, knife sharpeners, razors, and recently fine drills and fine jewelry. Consumers are just as pleased with tungsten carbide jewelry as industries are with tungsten carbide tools and for the same reason, durability and price. In the past, platinum and palladium were the only alternatives to gold or silver jewelry, but tungsten carbide is stronger and less expensive than its rivals. For cutting metals, the best piece of equipment used to be tools made with diamonds, but tungsten carbide is a cheaper alternative with similar durability. Since superhard materials such as nanorods are extremely expensive to make because they require such high temperatures, tungsten carbide will be here to stay and its use will grow in prevalence.

Sources:

International Tungsten Industry Association, "Tungsten Carbide, An Overview," http://www.azom.com/details.asp?ArticleID=1203.