Fig. 1. Schematic of experimental device of WLSI

Fig. 2. Loading curve and determination of time steps. (a) Loading curve; (b) deformation versus time

Fig. 3. Forming heights and morphologies of WLSI at different temperatures. (a) Formation height ; (b) morphology at 150 ℃;(c) morphology at 300 ℃

Fig. 4. Atomic fractions and distributions of surface oxygen element of formed part at different impact temperatures. (a) 25 ℃; (b) 150 ℃; (c) 300 ℃

Fig. 5. Deformation speeds and stress maps at different imprinting temperatures. (a) Deformation speed; (b) stress curves of cross section (S33); (c) stress map at 25 ℃; (d) stress map at 150 ℃; (e) stress map at 225 ℃; (f) stress map at 300 ℃

Fig. 6. Forming height and contour map. (a) Forming heights at different impact times; (b) contour map after three consecutive impacts

Fig. 7. Atomic fractions and distributions of surface oxygen element after multiple WLSI. (a) One time; (b) two times; (c) three times

Fig. 8. Nano-indentation test results of WLSI. (a) Load-displacement curves; (b) nano-hardness and elastic modulus

Fig. 9. TEM microstructures of aluminum foil before and after single WLSI. (a) Grain shape before WLSI; (b) low density dislocations before WLSI; (c) high density dislocations after WLSI; (d) inverse Fourier transform graph of high density dislocations after WLSI; (e) dislocation cells after WLSI; (f) sub-grains after WLSI

Fig. 10. Deformation speeds and stresses at different impact times. (a) Stress map after one impact; (b) stress map after two impacts; (c) stress map after three impacts; (d) stress curves of cross section (S33); (e) deformation speed