by Dr John Ormerod NdFeB magnets, compositions and processing technologies have been the subject of controversy ever since its announcement and the key inventive claims were filed over 40 years ago. Both General Motors Corporation (GMC) and Sumitomo Special Metals Corporation (SSMC) made claims of being first to discover magnets based on the Nd2Fe14B tetragonal […]
Permanent Magnets; Materials, Applications and Economics Issue S
While it’s true that most permanent magnet (PM) material ever commercialized (except Lodex for obvious environmental and safety reasons) are still in some limited use today there are only 5 classes of PM materials/types that are commercially important. So how do we get decent estimates of the relative market sizes for the different magnet options? […]
Bonded Magnet Materials and Processing Options
Bonded magnets are an important but often overlooked group of products that magnetic circuit and device designers should consider when choosing the optimum permanent magnet type for their specific application need.
The Application of Permanent Magnets in Magnetic Sensors
Permanent magnets are ubiquitous in modern societies. Devices which use permanent magnets include motors, sensors, actuators, and acoustic transducers, just to name a few
NdFeB magnets: Where is the Next Breakthrough Permanent Magnet Material?
By Dr. John OrmerodTechnical Adviser / Bunting-DuBois IntroductionIt’s interesting to note that no major new permanent magnet material has been introduced since NdFeB in the 1980’s; in fact, it’s now 35 years ago since the announcement of NdFeB magnets at the 29th MMM conference held in Pittsburgh, PA in November 1983; a long time ago […]
Types of Rare Earth Magnets: Part 3
MQ3 Fully Dense NdFeB Magnets By Dr. John OrmerodTechnical Adviser / Bunting-DuBois Fully dense NdFeB magnets can also be produced from melt spun powders by a combination cold pressing, hot pressing and thermomechanical forming technologies. This process was originally developed by Magnequench and is known as the MQ3 process. Grain orientation in MQ3 magnets is […]
Types of Rare Earth Magnets: Part 2
Melt Spun/Jet Milled Isotropic Bonded Magnets By Dr. John OrmerodTechnical Adviser / Bunting-DuBois In the early 1980’s, General Motors Corporation (later Magnequench) pioneered the use of melt spinning to produce an isotropic NdFeB powder which is used primarily in bonded magnet production; either compression bonding or injection molding as shown below. The principle of melt-spinning […]
Types of Rare Earth Magnets: Part 1
Fully Dense Rare Earth Magnets by Powder Metallurgical Processing By Dr. John OrmerodTechnical Adviser / Bunting-DuBois The powder metallurgical method is the most common method of manufacturing fully dense NdFeB (and SmCo-based) magnets. Below is an outline outline that is typical for NdFeB magnet production process. Today strip casting is the preferred method alloy production. […]