Authors: Associate Professor Rajesh Kant
Abstract: The present work examines the relationship between anisotropic growth velocity and the mechanical behaviour of the Sn–Pb–Bi–Cd eutectic composite. The alloy was prepared from the constituent metals using the heat-chill method and its eutectic melting point was determined by differential scanning calorimetry. The composition investigated was Sn 13.1 wt%, Pb 27.3 wt%, Bi 49.5 wt%, Cd 10.1 wt%, with a measured eutectic melting point of 342.2 K. Macrohardness-related strength modes and Vickers microhardness were evaluated as functions of growth velocity, indentation time and applied load. At 3.10 × 10⁻⁷ m s⁻¹, the modulus of rupture is 43.30 × 10⁶ N m⁻², tensile strength is 52.40 × 10⁶ N m⁻² and compressive strength is 57.10 × 10⁶ N m⁻². Microhardness increases from 14.50 kg mm⁻² at 0.50 × 10⁻⁷ m s⁻¹ to 27.20 kg mm⁻² at 3.10 × 10⁻⁷ m s⁻¹, then decreases to 13.30 kg mm⁻² at 7.50 × 10⁻⁷ m s⁻¹. The results demonstrate a characteristic optimum or moderate-growth region in which the fibrous eutectic microstructure and mechanical response are maximized. The observations support the interpretation that directional/fibrillar growth produces stronger, more coherent microstructures than instantaneous or very rapid growth.
