Journal of Research in Materials and Metallurgical Engineering

Authors: Paulson Varghese, Febin Joseph, Merrin John Varkey, Don Dominic, M. Pooja, V. Vijeesh and K. G. Samuel

Abstract: 

Aluminum-silicon alloy A356 was exposed to different durations at various solutionizing and ageing temperatures before and after strontium modification. The effect of Sr-modification on the microstructures and hardness were examined as a function of heat treatment parameters (temperature and time). The combination of Sr-modification and heat treatment increased the hardness of the alloy. The Sr-modification process also influenced the heat treatment parameters of the alloy as it decreased the solutionizing time by 4 hrs and increased the ageing time by 2 hrs to obtain the peak hardness. It was deduced that the modification favored the spheroidization of eutectic silicon to decrease the solutionizing time, however, the increase in ageing time was due to the interaction of modifiers with the Mg2Si precipitates.