Magnetorheological Fluids: Smart Liquids in Magnetic Fields
What are magnetorheological fluids? A plain-language look at smart liquids that stiffen in a magnetic field, and where they are used.
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110 Articles
Knowledge base
Practical articles on permanent magnet materials — organized by topic, sortable by date.
Fundamentals
Core concepts of magnetism and magnet materials — read these first.
33 articlesMagnetic Levitation: Floating Without Touching
How magnetic levitation works in plain English: repelling poles, maglev trains, floating displays and frictionless bearings.
Magnetostriction: When Magnets Change Shape
Magnetostriction explained: why magnetic materials change shape slightly in a field, what causes transformer hum, and how sonar and actuators use the effect.
Ferrofluids: Liquid Magnets Explained
Ferrofluids explained: liquids full of nanoscale magnetic particles that spike up around magnets, and their real jobs in speakers, seals and dampers.
Electromagnets: Magnets You Can Switch On and Off
Electromagnets explained: a coil and iron core that switch on and off with current, and where they beat permanent magnets — from scrap yards to MRI machines.
Magnetic Recording and Storage: Data on Magnets
How magnetic recording stores data: tiny magnetized regions on hard drives and tape, read/write heads, and why solid-state drives took over.
Magnetization Curves: How Magnets Respond to Fields
What a magnetization (B-H) curve shows: saturation, the hysteresis loop, and why the demagnetization curve decides how strong a permanent magnet really is.
Magnetic Shielding: Blocking Magnetic Fields
Magnetic shielding explained: how high-permeability materials like mu-metal and steel redirect magnetic fields instead of blocking them, and where shields are used.
Physical Properties of Sintered NdFeB
Density, electrical resistivity and thermal expansion of sintered NdFeB — each explained in one sentence, and why it matters in motors, rings and assemblies.
Mechanical Properties of Sintered NdFeB
Why neodymium magnets chip and crack so easily: sintered NdFeB is hard but brittle. How to handle, machine and mount magnets without breaking them.
Permeability and Reluctance: The Circuit View of Magnets
Permeability and reluctance explained simply: why air gaps eat magnetic force, and why a steel return path makes the same magnet pull several times harder.
Bonded NdFeB Magnets: Magnets in Any Shape
Bonded magnets: magnetic powder mixed with plastic and molded into almost any shape — weaker than sintered, but wonderfully flexible.
Finite Element Simulation of Magnet Fields
What is finite element analysis (FEA)? A plain-language look at how engineers simulate magnet fields on a computer, why it matters, and the common software tools.
SmFeN: The Next-Generation Rare Earth Magnet
SmFeN is the promising newcomer of rare-earth magnets: nearly as strong as NdFeB in theory, better in heat — but it falls apart above 600 °C, so today it's bonded-only.
Hot-Pressed and Hot-Deformed NdFeB Magnets
Hot-pressed magnets: NdFeB powder squeezed at high temperature into a dense, strong magnet — the quiet workhorse behind power-steering motors in millions of cars.
Rare Earths and Magnetism: Why 4f Electrons Matter
Why are rare-earth magnets so strong? A plain-language answer: electrons deep inside rare-earth atoms make big magnetic moments that refuse to flip.
Why Are Rare Earth Magnets Expensive?
Why rare-earth magnets cost what they cost: the elements aren't rare — separating them is brutally hard, and the supply chain is concentrated in one country.
Magnet Lifetime: How Long Do Permanent Magnets Last?
How long do permanent magnets last? Decades — basically forever, if they are kept cool and protected from corrosion. Magnet aging explained in plain language.
Magnetic Materials: A Family Tree
How magnetic materials are classified: soft, semi-hard and permanent magnets — and the simple family tree from cheap ferrite to the strongest NdFeB.
Shape Anisotropy and Demagnetizing Fields
Why a long thin rod magnet holds its strength while a flat disc demagnetizes: shape anisotropy and the demagnetizing field, explained simply.
Eddy Currents in Permanent Magnets
Why magnets get hot inside motors: eddy currents explained in plain language, and the three ways motor designers keep magnets cool.
Magnetic Domains: How a Magnet Remembers Its Direction
What magnetic domains are: the tiny regions inside a magnet that line up when it is magnetized - and why that is how a magnet remembers its direction.
H, B, M, J: The Four Magnetic Quantities Explained
H, B, M and J in plain English: applied field, flux density, magnetization and polarization - one sentence each, with the units engineers use.
Magnet Grades Explained: What N35, N42H and N50SH Mean
How to read NdFeB grade names like N35, N42H and N50SH: the number is the strength, the letters are the heat resistance. Simple rule, examples and a reference table.
Why Magnets Hate Heat: Temperature Behavior Explained
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