In situ multi-layer functionally graded materials by Electromagnetic Separation method

This paper proposes a new technique of in situ multi-layer functionally graded materials (FGMs) by Electromagnetic Separation method using alloy with two or more kinds of primary particles formed in different temperature ranges. In situ three layers FGMs were produced successfully by Electromagnetic Separation method using the alloy with nominal composition Al–22% Si–3.9% Ti–0.78% B. The three layers are respectively the layer of the primary ternary intermetallic compound Al–Si–Ti particles with rich Si, the layer of the primary Si particles, and the layer of the Al–Si eutectic structure. The reason why these three layers appeared under the electromagnetic field is that the first primary Al–Si–Ti particles with rich Si, the second primary Si particles and the Al–Si eutectic structure are formed in different temperature ranges. In the produced samples, interfaces between two layers are gradually transitional in the microstructure.