Molybdenum is mainly known as an additive that makes steel harder and more resistant to heat and rust, but it’s also used in a number of other areas, including many that have bright prospects. And some exciting new research may see it soon take hold in the fast-growing electronics field.
Heat and pressure resistance give molybdenum broad appeal
Sixty-one percent of the world’s molybdenum (or “moly” for short) is used in steelmaking, according to the London Metal Exchange (LME). That is mainly because it has two characteristics — an extremely high melting point of 2,623 degrees Celsius and a strong resistance to pressure and corrosion — that make it an important alloying agent in the steelmaking process. By adding just a small amount of the metal steelmakers can make steel much harder and far less prone to melting in extreme temperatures.
These two characteristics also make moly an ideal high-performance industrial lubricant. The LME says that 13 percent of global moly consumption goes toward chemical uses, with lubricants accounting for a major portion.
Benefits of molybdenum-based lubricants make them irreplaceable to manufacturers
Molybdenum lubricants are made of molybdenum disulfide (MoS2), which mining companies extract from molybdenite ore through crushing, grinding and flotation processes.
Fine particles of molybdenum disulfide make an excellent lubricant, particularly in extreme conditions. In addition, molybdenum disulfide readily adheres to metal surfaces, creating a heat-resistant barrier that keeps moving parts from coming together, creating friction and eventually seizing up. Once added, in fact, molybdenum disulfide can create a bond to the metal that is so strong that the only way to remove it is to grind it off.
Molybdenum disulfide is either used in its pure form — a black powder — or as an additive to oil or grease. It can also be alloyed directly into steel. It initially found widespread use in military and aerospace applications, such as jet engines, but thanks to moly’s wide availability, it can be found in just about any mechanical lubricant in a wide range of industries, including mining, agriculture and car manufacturing. There are a number of more obscure uses as well: railways, for example, use it to lubricate curved railroad tracks, thereby lessening the wear on train wheels. Bullets are also coated with molybdenum disulfide to reduce fouling of the gun barrel and increase accuracy at longer ranges.
Molybdenum, in steel and lubricants, is another way to profit from rising car demand
In 1961, Ford Motor Company developed a grease containing both molybdenum disulfide and polyethylene for use in ball joints, wheel bearings and other fast-moving components.
Today, molybdenum disulfide is also used as a brake lubricant and in the constant-velocity joints in front-wheel-drive cars. It can also be found in some fuel supplements that aim to reduce rust and remove harmful impurities that can reduce an engine’s performance.
Demand for moly-based lubricants should continue to rise as the recovering global economy increases car demand. In the US, for example, car sales rose 20 percent in the month of August from August 2011, according to industry research firm Edmunds.
Over the longer term, car sales are expected to continue climbing as citizens of developing nations grow wealthier. China, for example, saw its new car sales jump 11 percent in July from July 2011, according to the Financial Times. That is despite a broader slowdown in the country’s economy.
Electronics market could be a new growth area for moly
Molybdenum disulfide made headlines last month when researchers at the Massachusetts Institute of Technology revealed that they are using the material to make ultra-thin electronic components that could fundamentally change the way we interact with technology.
So far, MIT researchers have made a number of micro-sized electronic components using sheets of molybdenum disulfide that are just one millimeter thick, including a NAND gate (a basic element that can be used to carry out nearly any kind of logic operation), an oscillator and a memory device. These developments open the possibility of ultra-thin, energy-efficient TV screens, wearable computers and other devices, such as chemical sensors that are far more sensitive than anything on the market today.
Since 2004, researchers have been using graphene for this type of experimentation, but graphene lacks a bandgap, a critical component that allows a transistor to stop or start the current passing through it. Unlike graphene, which must be specifically modified to include a bandgap, molybdenum disulfide naturally contains one.
“It’s the most exciting time for electronics in the last 20 or 30 years,” said Tomás Palacios, an associate professor of electrical engineering and computer science at MIT.
This research, of course, is still in its infancy, but it’s a great example of how molybdenum’s versatility will help keep it in demand for many years to come.