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What is hydrogen decrepitation?
Hydrogen Decrepitation is a process step used in the production of Neodymium magnets to create extremely small grains in the material. Neodymium magnets must have very small grains averaging about 5 micrometers in order to have the best magnetic properties.
What is material NdFeB?
Neodymium Iron Boron Magnets Neodymium iron boron (NdFeB), or “neo” magnets offer the highest energy product of any material today and are available in a wide range of shapes, sizes and grades.
Where are NdFeB magnets used?
In the field of information technology, neodymium magnets are particularly used in hard disc drives, mobile phones, video and audio systems of television [1]. Neodymium magnets are also commonly used in magnetic separators, filters, ionizers, in production of on–off buttons, safety sector and security systems.
How are NdFeB magnets made?
Fully dense Neodymium Magnets (also known as neo magnets, neodymium iron boron, neo, or rare earth magnets) are usually manufactured by a powdered metallurgical process. Micron size Neodymium and iron boron powder is produced in an inert gas atmosphere and then compacted in a rigid steel mold or in a rubber mold.
What’s the strongest magnet in the world?
But scientists at the University of California, Berkeley, have recently made a hybrid magnet that is 300,000 times as strong as the earth’s magnetic field! The magnet, named RD-3, is only about 3 feet long, and weighs several tons. Answer 2: The strongest magnet ever build is 22-foot tall and weights 34 tons.
What is the world’s strongest magnet used for?
The University of Florida Brain Institute lays claim to having the largest magnet used for body imaging, a 24-ton behemoth that can explore a long list of injuries and diseases of the brain and spinal cord. At 11.7 teslas, it is 234,000 times more powerful than the Earth’s natural magnetic field.
What is hydrogen decrepitation (HD)?
Fully dense, sintered NdFeB-type magnets have been subjected to the hydrogen decrepitation (HD) process. The resultant powder has been subsequently processed in one of two ways in order to produce permanent magnets.
Which material can be decrepitated by hydrogen in a magnet?
It is likely that the only material in the system to be decrepitated by hydrogen would be the sintered magnet.
How is the progress of the hydrogen absorption process monitored?
The progress of the HD process was monitored by the rise in temperature due to the exothermic nature of the hydrogen absorption reaction and by the pressure drop in the reaction vessel, which occurs only while the absorption takes place.
What happens when hydrogen is collected at the grain boundaries?
As the hydrogen collects in the grain boundaries, the metal begins to disintegrate as can be seen in the short video above. The decrepitated material is now ready for the next step in the process, where it will be jet-milled to achieve the correct grain size and shape.