- Curie Temperature
- Temperature Resistances
- Bonded vs Sintered Neodymium Magnets
- Focused/Focusing/Shaped Field Magnets
Isotropic means a material has the same properties (mechanical, magnetic, and metallurgical properties) in all (x, y and z) directions.
Anisotropic means that a material has different properties in different directions. Sintered Neodymium magnets are anisotropic, and Bonded Neodymium magnets are isotropic.
Together, these two kinds of Neodymium magnets offer designers many different design options.
The Curie temperature (named after scientist Pierre Curie) is the temperature where permanent magnets lose their magnetism due to the disorder caused by high temperatures.
The strongest type of magnetism. Permanent magnets are typically ferromagnets.
If a magnet contains iron, nickel and cobalt and rare earths, it is almost certainly ferromagnetic.
Neodymium magnets are available in different temperature grades to meet the requirements of various applications at higher temperatures and higher opposing magnetic fields.
The technical term for this is Coercivity, also known as coercive force.
See Isotropic/Anisotropic above.
Sintered Neodymium magnets can be designed with focused field lines that concentrate their magnetic field in certain areas to increase the magnetic performance of a system, resulting in greater efficiency, reduced system size, cost and weight.
Neodymium (Nd) is the element after which Neodymium magnets are named.
Praseodymium (Pr) is so close to Neodymium (Nd) that it is used in Neodymium magnets. Pr is right next to Nd on the periodic table and it's properties are very similar to those of Nd. So similar that about 25-35% of the Nd in NdFeB is actually Pr.
Dysprosium (Dy) is the major element added to Neodymium magnets to increase their performance at higher temperatures and when exposed to high opposing magnetic fields.
Terbium (Tb) is another major element (instead of or in addition to Dysprosium) added to Neodymium magnets to increase their performance at higher temperatures and when exposed to high opposing magnetic fields.
Lanthanum (La) is a light rare earth element that has been shown on an R&D scale to be an acceptable partial substitute for Neodymium in association with Cerium in a controlled ratio and along with microstructural advancements. This new technology is expected to entre mass production at a future date.
Cerium (Ce) is a light rare earth element that has been shown on an R&D scale to be an acceptable partial substitute for Neodymium in association with Lanthanum in a controlled ratio and along with microstructural advancements. This new technology is expected to entre mass production at a future date.
Holmium (Ho)is sometimes added to Neodymium magnets to increase their performance at higher temperatures and when exposed to high opposing magnetic fields.
Heavy Rare Earth Elements. Refers to members of the Lanthanide series of the Periodic Table beginning with Europium and higher atomic weight elements Gadolinium (Gd), Terbium (Tb), Dysprosium(Dy), Holmium (Ho), Erbium (Er), Thulium (Tm), Ytterbium (Yb) and Lutetium (Lu).
Light Rare Earth Elements, beginning with Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pr) Samarium (Sm) and Europium (Eu).
- Neodymium Magnet Process Flow Steps
- Coatings and Electroplate of NdFeB magnets
- Neodymium Magnet safety
- Hydrogen Decrepitation
- Jet Milling
The production of Neodymium magnets depends on advanced materials engineering and processes. Here are the main steps:
Some common coatings of NdFeB magnets are Ni-Cu-Ni, Zinc, Color-Zn, Zn-Ni alloy, Passivation, Ni-Cu-with E-Nickel, IVD-Al, Al-121, LDE, LDP, and Everlube.
The amazingly strong magnetic field around Neodymium magnets is a great benefit for many applications, but this great strength can also create safety issues. Larger magnets are typically shipped in the unmagnetized state and are only magnetized after becoming part of an assembly.
Hydrogen Decrepitation is a process step used in the production of Neodymiummagnets to create extremely small grains in the material.
Jet milling is a clean way to mill decrepitated metal down to 3 µm powder. Jet milling is also more effective in this size range than ball milling.
- Magnetic Field
- Magnetic Flux
- Loss of Magnetic Flux
- Magnetic Domains
- Saturation Magnetization
- Remanent Magnetization, Br Definition
- What is Hysteresis?
- Hysteresis Loop
- BH Curve
- Eddy Current
- Eddy Current Loss
- Coercive Force
- Difference between Hcb and Hcj
- Permeance Coefficient
- What is ferromagnetic?
- Energy Product
- Flux Density
- North Pole
- Shear Force
- Focusing Magnets
A magnetic domain is a region within a magnetic material in which the individual magnetic moments of the atoms are aligned with one another and they point in the same direction.
Remanence is the remaining magnetic field found in the material after the applied magnetic field is reduced to zero
A hysteresis loop shows the relationship between the external magnetizing force and the induced magnetic flux density.
The plot of Hysteresis is known as a B-H curve, where B (The Material's Flux Density, measured in Teslas or Mega Gauss) is plotted on the vertical axis and H (The External Applied Magnetizing Force, measured in Amperes per meter) is plotted on the horizon
Coercive force means Coercivity.
- Neodymium vs Ferrite magnets
- Neodymium vs Samarium Cobalt magnets
- Neodymium vs Alnico magnets
If efficiency, especially efficiency-per-unit volume is the deciding factor, designers often choose Neodymium magnets, which deliver up to 20 times the magnetic field per unit volume compared to ferrite magnets, greatly reducing system size and often causing a cascade effect of size reduction throughout the entire system.