Influence of Growth Rate on Eutectic Spacing, Microhardness, and Ultimate Tensile Strength in the Directionally Solidified Al-Cu-Ni Eutectic Alloy

In this work, the mechanical properties of the Al-Cu-Ni eutectic alloy, Al-32.5 wt pct Cu-1 wt pct Ni, were investigated in terms of the dependency on growth rates. The Al-Cu-Ni eutectic alloy was directionally solidified at a constant temperature gradient, G = 4.93 K mm⁻¹, with a wide range of growth rates (V = 9.25 to 2056.68 µm s⁻¹) using a Bridgman-type directional solidification furnace. The eutectic spacing (λ), microhardness (HV_T), and ultimate tensile strength (σ_UTS) were measured with standard techniques. The dependences of λ, HV_T, and σ_UTS on V for directionally solidified Al-Cu-Ni eutectic alloy were experimentally obtained using regression analysis. The results obtained in the present work were compared with the similar experimental results in the literature. Finally, the elastic energy dependence on growth rates for Al-32.5 wt pct Cu-1 wt pct N alloy was determined from their nominal stress–strain plots.