Nanoeutectic Composites: Processing, Microstructure and Properties

Abstract

Nanostructured alloys exhibit high strength and large elastic strain limit. Unfortunately, the plasticity of these alloys is disappointingly low at room temperature than that of the coarse grain counterparts. In this work, a series of nanoeutectic composites have been developed in Ti–Fe and Ni–Zr based alloys, which exhibit very high strength, like bulk metallic glasses and large plasticity at room temperature. Systematic investigations have been performed to reveal the effect of alloy addition on the alteration of the microstructure and the properties of nano-lamellar phases. Even though, in some cases, alloy addition stabilizes micrometer-sized proeutectic bcc/fcc solid solution phase(s) with dendritic morphology, but the residual melt solidifies into a binary nanoeutectic comprised of alternating soft bcc/fcc phase together with hard intermetallic phase. Furthermore, electron microscopic studies of differently deformed specimens and strain rate jump test have been performed to reveal the role of eutectic lamellae on the strain rate sensitivity and to explore the origin of plasticity in nanoeutectic composites.