Generation of Nano Phase in Al-Sr Eutectic Alloy

The impact of cooling rates on the microstructural evolution of an Al-Sr eutectic alloy was investigated. Two distinct cooling rates, 0.02 and 57.12 °C/s, were employed during the solidification process. To elucidate the characteristics of phase transformations and microstructural evolution during solidification, thermal analyses were conducted on the recorded cooling curves. Both the first and second derivatives of these curves were examined. At the slower cooling rate, the microstructure predominantly consisted of the eutectic Al phase and the eutectic Al-Sr phase, as identified by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Conversely, at the higher cooling rate of 57.12 °C/s, primary Al phases were observed, indicating a significant departure from equilibrium solidification conditions. Additionally, a substantial quantity of nanosized eutectic Al-Sr particles was detected, resulting in a markedly refined microstructure.