Precipitation response of the magnesium alloy WE43 in strained and unstrained conditions

Highlights: • The precipitation sequence in magnesium alloy WE43 is dependent on initial microstructural state. • The solution treated samples follows the precipitation sequence as: solution treated → β″ → β′ → β₁ → β. • β₁ and β precipitates form after long ageing periods. • In pre-strained condition, the precipitation sequence modifies to: solution treated → strained → (β′ + β₁); β₁→β. - Abstract: The precipitation behavior of the magnesium alloy WE43 (Mg–4%Y–2.3%Nd–0.5%Zr) has been studied in strained and unstrained conditions using Transmission Electron Microscopy (TEM). Ageing treatments were carried out at three temperatures, namely 210 °C, 230 °C and 260 °C. The precipitation sequence during static aging of solution treated (ST) samples has been identified as ST → β″ → β′ followed by the formation of β₁ and equilibrium β precipitates form after very long ageing periods. Dynamic precipitation was observed during high temperature deformation, leading to the formation of β′ and intermediate β₁ precipitates. The strained samples, when further heat treated, resulted in the transformation of β₁ into β equilibrium precipitates. The sequence of dynamic precipitation is ST → β₁ → β and ST → β′