Precipitation hardening owing to δ′ Al3Li in low activation Al–3 Li–12Si–3Mg alloy

Abstract

The precipitation hardening behaviour owing to ordered δ′ Al₃Li in an Al–3Li–12Si–3Mg (wt-%) based alloy was investigated during aging between room temperature and 523 K after quenching from between 723 and 823 K. The induced radioactivity level of this alloy is very low, suitable for fusion reactor structures. Effects of aging temperature, solutionising temperature, and pretreatments on precipitation hardening were examined in detail. Tensile properties were also examined in the as quenched condition as a function of testing temperature between room temperature and 673 K. Yield stress exhibited a positive temperature dependence between room temperature and 523 K and decreased abruptly above 523k with increasing test temperature. The precipitation behaviour of δ′ and the strengthening mechanisms owing to δ′ were discussed.

MST/1100