Fabrication of Ni/Epoxy Resin Functionally Graded Materials via a Reciprocating Magnetic Field

A reciprocating magnetic field was applied to prepare functionally graded materials (FGM) comprised of magnetic Ni and nonmagnetic epoxy resin. The reciprocating field was achieved by shifting a cylindrical permanent magnet along the axis towards or away from the sample in cycle. Ni decreases gradually with the distance from surface to bottom, which attributes to the continuously changing driving force on magnetic Ni particles by the reciprocating field. The gradient of Ni increases with cycle times, while decreases with the increase of the velocity of the reciprocating magnet. The results reveal that it is a more effective way to prepare FGMs by using reciprocating magnetic field compared with normal static magnetic field.