Abstract
In this study, a new method for producing aluminum-matrix composites locally reinforced with SiC particles is proposed, which applies the electromagnetic (e.m.) force to accumulate SiC particles in the periphery of an aluminum cylinder. A high frequency induction coil is used to impose the e.m. force in an aluminum melt containing SiC particles (21 μm in average diameter). The experimental conditions are as follows: weight of aluminum 0.18 kg; diameter of crucible 0.04 m; holding time of e.m. force 8-36 s; frequency 30, 80, 200 kHz; coil current 42-163 A. Particles are accumulated in the periphery of aluminum during several to several ten seconds. The particle concentration increases with increasing coil current and the thickness of the particle accumulated layer decreases with increasing frequency because of the skin effect. The particle-accumulated surface of the solidified aluminum ingot achieves a good wear resistance. The composite which is reinforced only its surface with SiC particles by this electromagnetic method, can be compressed more easily than the composite homogeneously reinforced with SiC particles.
