Precipitation Kinetics and Evaluation of the Interfacial Mobility of Precipitates in an AlSi_7Cu_(0.5)Mg_(0.3) Cast Alloy

摘要

Heat treatment of cast aluminum alloy parts enables the formation and distribution of nano-sized precipitates through an optimum sequence including solution-izing, quenching, and artificial aging. Quaternary alloys are particularly challenging, and the present study aims to understand and outline the precipitation kinetics in the foundry AlSi_7Cu_(0.5)Mg_(0.3) alloy. Using techniques like differential scanning calorime-try (DSC), transmission electron microscopy (TEM), LKSZ kinetic equations, and microhardness testing, the precipitation kinetics was quantitatively characterized. Activation energies of the phase transformations were extracted using the Kissinger analysis of non-isothermal DSC runs conducted at different stationary heating rates. Finally, a first evaluation of the interfacial mobility of precipitates in this alloy was made using the developed methodology.