Key Parameters of Focus: Temperature and Corrosion

Determining whether or not to use SNT Group's "neo" magnets instead of our SmCo magnets, for example, is a function of the maximum temperature of the application, required magnetic output at typical use temperature and total cost of the system.

"Neo" magnets have some limitations due to their corrosive behavior. In humid applications, a protective coating is highly recommended. Coatings which have been used successfully include epoxy coating, nickel plating, and/or a combination of these coatings.

SNT Group also has the capability to apply various treatments such as Parylene coating to "neo" magnets. Effectiveness of coating is dependent upon the quality of the base material. At SNT Group, we pride ourselves in only using the best base materials that are well-tested materials with long manufacturing track records of optimal performance.

SNT Group's High Performance NeFeB Product Range Provides High Performance Under a Variety of Conditions.

Key Benefits of NdFeB Magnets: From Automotive to Renewables and beyond.

Extremely strong for their size, Neodymium (Nd-Fe-B) rare earth magnets are composed of Neodymium, Iron, Boron and a few transition metals:

• Manufacturing - in general, the elements are melted together and milled into a powder that is dry-pressed to shape in the presence of a magnetic field. The material is then sintered, ground to dimension, magnetized and tested.
• They are called “rare earth” magnets because the elements of neodymium are classified as such in the lanthanides section of the Periodic Table of the Elements.
• Tolerances - for as-pressed material, tolerance on the thickness (direction of magnetization) is +/– .005”. Other dimensions are +/– 2.5% or +/– .005”, whichever is greater.
• According to International Magnetics Association (IMA) standards, visual imperfections such as hair-line cracks, porosity and minor chips are commonly found in sintered magnets. A chipped edge is considered acceptable if no more than 10% of the surface is missing. Cracks are acceptable as long as they do not extend across more than 50% of the pole’s surface.
  
• Magnetizing and Handling - Neodymium magnets are very brittle and very strong magnetically. Magnets can chip if allowed to “jump” at an attracting object.
  
• Machining - Since Neodymium is prone to chipping and cracking, it does not lend itself to conventional machining methods. It can, however, be abrasively ground before being plated, but only with the use of liberal amounts of coolant.
• The coolant minimizes heat fracturing and the risk of fires caused by oxidized grinding dust