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Extensive research has been conducted on Ti–Fe–Sn ultrafine eutectic composites due to their high yield strength, compared to conventional microcrystalline alloys. The unique microstructure of ultrafine eutectic composites, which consists of the ultrafine-grained lamella matrix with the formation of primary dendrites, leads to high strength and desirable plasticity. A lamellar structure is known for its high strength with limited plasticity, owing to its interface-strengthening effect. Thus, extensive efforts have been conducted to induce the lamellar structure and control the volume fraction of primary dendrites to enhance plasticity by tailoring the compositions. In this study, however, it was found that not only the volume fraction of primary dendrites but also the morphology of dendrites constitute key factors in inducing excellent ductility. We selected three compositions of Ti–Fe–Sn ultrafine eutectic composites, considering the distinct volume fractions and morphologies of β-Ti dendrites based on the Ti–Fe–Sn ternary phase diagram. As these compositions approach quasi-peritectic reaction points, the α″-Ti martensitic phase forms within the primary β-Ti dendrites due to under-cooling effects. This pre-formation of the α″-Ti martensitic phase effectively governs the growth direction of β-Ti dendrites, resulting in the development of round-shaped primary dendrites during the quenching process. These microstructural evolutions of β-Ti dendrites, in turn, lead to an improvement in ductility without a significant compromise in strength. Hence, we propose that fine-tuning the composition to control the primary dendrite morphology can be a highly effective alloy design strategy, enabling the attainment of greater macroscopic plasticity without the typical ductility and strength trade-off. 

Sintering of nanoparticles to create films and patterns of functional materials is emerging as a key manufacturing process in applications like flexible electronics, solar cells and thin-film devices. Further, there is the emerging potential to use nanoparticle sintering to perform additive manufacturing as well. While the effect of nanoparticle size on sintering has been well studied, very little attention has been paid to the effect of nanoparticle shape on the evolution of sintering. This paper uses Molecular dynamics (MD) simulations to determine the influence of particle shape on shrinkage and neck growth for two common nanoparticle shape combinations, i.e., sphere-sphere and sphere-cylinder nanoparticles of different sizes. These sintering indicators are examined at two different temperature ramps. The results from this work show that depending on their relative sizes, degree of neck growth and shrinkage are both significantly affected by the nanoparticle shape. The possibility of using this phenomenon to control density and stresses during nanoparticle sintering are discussed.