Fabrication of Al–Si–Mg functionally graded materials tube reinforced with in situ Si/Mg2Si particles by centrifugal casting

The influences of various process parameters on the particle segregation ratio and the particle distributions involving the particle size and volume fraction of in situ primary Si/Mg2Si particles in tubes of Al–Si–Mg functionally graded materials (FGMs) fabricated by centrifugal casting were systematically investigated. The properties of hardness, wear resistance and thermal expansion of the tubes were examined. The results show that, (1) the FGMs tubes consisted of a reinforcement layer and an un-reinforcement layer; (2) the particle segregation ratio varied with various process parameters; (3) the volume fractions and sizes of primary Si/Mg2Si particles presented a graded distribution in the reinforcement layer; and (4) the FGMs had an advantage over the conventional motorcycle/automobile cylinder liners and the conventional materials Al–12Si–1Cu–1 Mg–1Ni alloy in the wear resistance and the thermal expansion property, respectively.