NaK, or sodium-potassium
alloy (commonly pronounced /næk/),[1] is an alloy of potassium (K) and sodium (Na) which is usually liquid at room
temperature.[2] Various commercial grades are available. NaK is
highly reactive with water (like its constituent elements) and may catch fire when exposed to air, so must be handled with special precautions.
Detailed description
Usage
Coolant
NaK has been used as the coolant in experimental fast neutron nuclear reactors. Unlike commercial plants, these are frequently shut down and
defuelled. Use of lead or pure sodium, the
other materials used in practical reactors, would require continual heating to
maintain the coolant as a liquid. Use of NaK overcomes this.
The Soviet RORSAT radar satellites
were powered by a NaK-cooled reactor.[8][9] As well as the wide
liquid temperature range, NaK has a very low vapor pressure, which is important
in the vacuum of space.
An apparently unintended consequence of this usage
as a coolant on orbiting satellites has been the creation of additional space debris. A number of these old
satellites are punctured by orbiting space debris—calculated to be 8
percent over any 50-year period—and release their NaK coolant into space. The
coolant self-forms into frozen droplets of solid sodium-potassium of up to
around several centimeters in size[10] and these solid
objects then become a significant source of space debris themselves.[11]
The Danamics LMX Superleggera CPU cooler uses NaK to
transport heat from the CPU to its cooling fins.[12]
Desiccant
Hydraulic fluid
NaK-77, an eutectic alloy of sodium-potassium, can be used as a hydraulic fluid in high-temperature
and high-radiation environments, for temperature ranges of 10 to 1,400 °F
(−12 to 760 °C). Its bulk modulus at 1,000 °F
(538 °C) is 310,000 psi (2.14 GPa), higher
than of a hydraulic oil at room temperature. Its lubricity is poor, so
positive-displacement pumps are unsuitable and
centrifugal pumps have to be used. Addition of caesium shifts the useful
temperature range to −95 to 1,300 °F (−71 to 704 °C). The NaK-77
alloy was tested in hydraulic and fluidic systems for the Supersonic Low
Altitude Missile.
PRICE
$55651.46/KG OR $25296.11/IB
For more information:
mobile: +2348039721941
contact person: emeaba uche
e-mail: emeabau@yahoo.com
website: www.franchiseminerals.com
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