Hafnium is a silvery ductile metal. It has almost the same chemical properties as zirconium, including its high strength and that is corrosion-resistant. Hafnium is rare and has larger density compared with zirconium. Hafnium has a strong ability to capture the neutron, making it a great material for control rods in the nuclear reactors. In fact, the nuclear industry roughly consumes half of the hafnium produced every year. Hafnium is also used as an additive to alloys. Recently, scientists at Intel and IBM found hafnium-based compounds can be applied to make their processors even smaller. Hafnium wires and other parts are also used in plasma cutting because of its ability to shed electrons into the air. Hafnium is also well known for imparting unique properties to certain high-temperature superalloys used in the aerospace industry, such as jet engines, allowing them to maintain high strength and stability when operating at very high temperatures. For example adding just 1-2% hafnium to nickel cobalt alloys increased operating temperatures from 1400ºC to 2000ºC, which increases fuel efficiency and reduces emissions associated with better combustion of the fuel.
New technological consciousness is emerging for the potential for hafnium uses in energy conservation and power generation. A passive cooling strategy using hafnium, which cools without any electricity could have a significant impact on global energy consumption. A research team from Stanford has developed a coating methodology with hafnium, called Photonic Radiative Cooling, that disperses the heat generated inside of the building and reflects sunlight. The result is cooler buildings that require less air conditioning. The Stanford invention is an ultrathin, multi-layered material containing hafnium oxide that deals with light, both invisible and visible, in a new way. At just 1.8 microns thick, the material is thinner than the thinnest aluminium foil.
Overexposure to hafnium metal and hafnium compounds may cause mild irritation of the eyes, skin, and mucous membranes.