Properties of composite materials with polymer matrix reinforced with Nd–Fe–B hard magnetic particles

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 and mechanical properties of composite materials was estimated. 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 HcB and slightly reduces remanence Br of composite. Addition of non-magnetic material decreases coercive force HcB and reduces remanence Br. 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. Influence of corrosive environments (water: 40 °C, 93% of humidity, 96 h and 5%NaCl solution: 35 °C and 6 h) of magnetic and mechanical properties and corrosive resistance of composite materials were established. The best corrosion resistance show composite materials with aluminum powder addition. Corrosive wear of magnets surface is the smaller and decrease with the growth of amount of metallic powder.