The Use of Chemical Coupling Agents to Improve the Performance of Polymer Bonded Nd-Fe-B Magnets

Jun Xiao, Hyun Seog Kim, Joshua Otaigbe, and Troy Tacke

Department of Materials Science and Engineering

Iowa State University of Science and Technology,

Ames, IA, USA

Annual Technical Conference - Society of Plastics Engineers

Abstract

Due to their poor heat-resistant properties, polymer bonded magnets are limited in their applications in aggressive environment. By using high temp. engineering polymers the heat-resistance of polymer bonded magnets can be significantly improved. However, the extreme tendency for thermal oxidn. of Nd-Fe-B alloy powder limits the use of high temp. polymers. This paper discusses the application of silane coupling agents to the thermoplastic polymer bonded Nd-Fe-B magnets. After the treatment of coupling agent, the thermal stability and oxidn./corrosion resistant properties of the Nd-Fe-B alloy powder at high temp. improved significantly, making it usable for high-temp. processing and high-temp. application. An enhanced wetting of the Nd-Fe-B particles in polymer matrix was obsd. The bonding between the Nd-Fe-B powders and polymer matrix was improved by the coupling agents. In turn, the enhanced bonding between the powder and the polymer dramatically increased the mech. properties of polymer-bonded Nd-Fe-B magnets.