Polymer Bonded Magnets. II. Effect of Liquid Crystal Polymer and Surface Modification on Magneto-mechanical Properties

Xiao, Jun and Joshua U. Otaigbe

Department of Materials Science and Engineering

Iowa State University, Ames, IA, USA

Abstract

The authors studied the effect of liq. crystal polymer (LC P) and surface modification of neodymium-iron-boron (Nd-Fe-B) magnetic alloy on the magneto-mech. behavior of poly(phenylene sulfide) (PPS) bonded Nd-Fe-B magnets to accelerate efforts to develop useful thermoplastic magnets with optimal performance. Blending the LCP with PPS provides the required balance of properties for the targeted applications. These properties include superior magneto-mech. performance at elevated temps., minimal melt viscosity at optimal LCP vol. fraction, high stiffness, and improved dimensional stability, making the thermoplastic magnets suitable for use at elevated temps. and in chem. corrosive environments where com. rare earth alloy magnets are not useable. Enhanced wetting of the magnetic Nd-Fe-B powders by the polymers, formation of reinforcing LCP domains, and interactions between the polymers and the magnetic powders probably are responsible for the beneficial function of the LCP and Nd-Fe-B surface modifier in the PPS bonded Nd-Fe-B magnets.