Fig. 1 True stress and strain curves of a-d as-cast S1 alloys and e-h as-cast S2 alloys

Fig. 2 Peak stresses of the S1 and S2 alloys under different deformation conditions

Fig. 3 Correlation between peak stress, strain rate, and temperature: a ${\text{ln}}\dot{\varepsilon } - {\text{ln}}\sigma$, b ${\text{ ln}}\dot{\varepsilon } - \sigma$, c ${\text{ ln}}\dot{\varepsilon } - {\text{ln}}\left[ {{\text{sinh}}\left( {\alpha \sigma_{\text{p}} } \right)} \right]$, d ${\text{ ln}}\left[ {{\text{sinh}}\left( {\alpha \sigma_{\text{p}} } \right)} \right] - 1000/T$

Fig. 4 Relations fitting between materials parameters and strains of the experimental alloys: a α; b n; c Q; d lnA

Fig. 5 Comparison between the experimental and predicted flow stress: a S1 alloy; b S2 alloy

Fig. 6 Processing maps of S1 and S2 alloys under different strain conditions: a, b, c S1 alloy, ε = 0.4, 0.8, 1.2; d, e, f S2 alloy, ε = 0.4, 0.8, 1.2

Fig. 7 TEM microstructure of β-Li phase at T = 473 K and $ \dot{\varepsilon }$ = 10 s−1: a S1 alloy; b S2 alloy

Fig. 8 TEM dislocation configuration of S1 alloy: a, b T = 513 K, $ \dot{\varepsilon }$ = 1 s−1; c, d T = 553 K, $ \dot{\varepsilon }$ = 1 s−1; e, f T = 513 K, $ \dot{\varepsilon }$ = 0.01 s.−1

Fig. 9 TEM dislocation configuration of S2 alloy: a, b T = 513 K, $ \dot{\varepsilon }$ = 1 s−1; c, d T = 553 K, $ \dot{\varepsilon }$ = 1 s−1; e, f T = 513 K, $ \dot{\varepsilon }$ = 0.001 s−1