Precipitation hardening of A356 Al alloy produced by gas induced semi-solid process

► Aged hardening of semisolid cast A356 alloy produced by GISS process was studied. ► The optimum aging condition was 165 °C-18 h with the highest hardness of 96 HRE. ► The strain hardening exponent for the 165 °C-18 h aged specimens was 0.156 ± 0.048. ► Fine β″ needle-like precipitate was responsible to peak aged strengthening. ► The activation energy for the precipitation process of the alloy was 128,717 J/mol.