Microstructures and wear resistances of hybrid Al–(Al3Ti+Al3Ni) FGMs fabricated by a centrifugal method

The Al based functionally graded materials (FGMs), reinforced by a hybrid of Al3Ti platelets and Al3Ni granular particles, were fabricated by the centrifugal method with both ingots of commercial Al–5mass%Ti and Al–20mass%Ni master alloys. The ratios of Al–Ti and Al–Ni alloys were 3:1, 1:1 and 1:3 (in mass), and the applied G numbers are 30, 50 and 80. The microstructures of hybrid Al–(Al3Ti+Al3Ni) FGMs were observed with an optical microscope (OM) and a scanning electron microscope (SEM). Since the gradient distributions in orientation of Al3Ti platelets and in particle size of Al3Ni primary crystal particle were expected to be formed in the fabricated hybrid Al–(Al3Ti+Al3Ni) FGMs, detail observations of the orientation of Al3Ti platelets and the size of Al3Ni granular particles were performed. The wear resistance of the FGMs was measured by an Okoshi-type wear machine. Based on the experimental results, the advantages of hybrid Al–(Al3Ti+Al3Ni) FGMs were discussed.