Impact of substrate temperature on rapid solidification of an Al-Cu eutectic alloy

Abstract

An aluminium-copper eutectic alloy has been subjected to rapid solidification, utilising the "gun" technique, with different substrate temperatures to evaluate its influence on the cooling rate and microstructure. At all temperatures, the microstructure is essentially non-uniform and consists of metastable solid solution (with decomposition products) as well as eutectic regions. The solid state decomposition of the metastable solid solution is strongly dependent on the substrate temperature and leads to the formation of different metastable precipitates and consequent changes in microstructure. The origin of the different microstructures is discussed.