Structure and properties of composite materials with polymer matrix reinforced Nd–Fe–B hard magnetic nanostructured particles

Abstract

Investigation results of the polymer matrix hard magnetic composite materials with nanostructured particles of the powdered rapid quenched Nd–Fe–B strip are presented at this paper. The Nd–Fe–B powder was mixed with powders of iron, aluminum, CuSn10 casting copper alloy with tin, high-alloy X2CrNiMo17-12-2 steel. Epoxy resin has been used as the matrix (2.5 wt.%). The composites were unilaterally and uniaxially pressed at room temperature under the pressure of 800–900 MPa and cured afterwards for 2 h at 180 °C. The influence of the kind of addition materials on magnetic, mechanical and electrical properties of composite materials was estimated. Metallographic examination of powders morphology and the structure of composite materials, EDS and XRD analysis were made. Investigations of magnetic properties of composite materials show the influence of the addition material. It was found out that addition of soft magnetic material decreases coercive force H cB and slightly reduces remanence B r of composite. Addition of non-magnetic material decreases coercive force H cB and reduces remanence B r. The fact is that employment of an addition of a metal material powder, like iron, aluminum, CuSn10 casting alloy of copper with tin, as well as of the X2CrNiMo17-12-2 high-alloy steel causes the decrease of the magnetic properties of the composite material, yet it improves its mechanical properties. Addition of the iron powder has the biggest effect on improvement of the compressive strength, whereas the X2CrNiMo17-12-2 high-alloy steel powder has the most advantageous influence on hardness increase. Metallographic examination of the structure reveals uniform distribution of Nd–Fe–B powder in the polymer matrix, grains are irregular elongated in one direction. However, distribution of additions in the polymer matrix is regular, agglomerations of powders of aluminum, and iron have been observed. XRD analysis has identified the hard magnetic phase Nd 2Fe 14B.