Fig. 1. Schematics of dynamic compaction of powder by laser shock. (a) Experiment system; (b) principle

Fig. 2. Experimental instruments of dynamic compaction by laser shock. (a) Overall layout of instruments during experiment; (b) mold

Fig. 3. SEM morphologies of powders. (a) Nanometer nickel powder; (b) nanometer copper powder

Fig. 4. Models of copper-nickel with different mixing ratios. (a) 2×2 model, 25%Cu-75%Ni; (b) 2×2 model, 50%Cu-50%Ni; (c) 2×2 model, 75%Cu-25%Ni; (d) 4×4 model, 25%Cu-75%Ni; (e) 4×4 model, 50%Cu-50%Ni; (f) 4×4 model, 75%Cu-25%Ni

Fig. 5. Obtained powder-compacted billet image and relative density of compacted billet versus laser energy. (a) Image of 75%Cu-25%Ni powder-compacted billet; (b) relationship between relative density of compacted billet and laser energy

Fig. 6. SEM images of copper-nickel compacted billet surfaces. (a)(b)(c) Microscopic surfaces after preloading; (d)(e)(f) microscopic surfaces after compaction by 1.2 J laser impact; (g)(h)(i) microscopic surfaces after compaction by 1.8 J laser impact

Fig. 7. Microhardness values of copper-nickel billet under 1.8 J laser impact. (a) Schematic of path selection; (b) microhardness of 25%Cu-75%Ni billet; (c) microhardness of 50%Cu-50%Ni billet; (d) microhardness of 75%Cu-25%Ni billet

Fig. 8. Total atomic energy changes in relaxation process. (a) 2×2 model; (b) 4×4 model

Fig. 9. Lattice distributions after relaxation. (a) 2×2 model, 25%Cu-75%Ni; (b) 2×2 model, 50%Cu-50%Ni; (c) 2×2 model, 75%Cu-25%Ni; (d) 4×4 model, 25%Cu-75%Ni; (e) 4×4 model, 50%Cu-50%Ni; (f) 4×4 model, 75%Cu-25%Ni

Fig. 10. Dislocation distributions after relaxation. (a) 2×2 model, 25%Cu-75%Ni; (b) 2×2 model, 50%Cu-50%Ni; (c) 2×2 model, 75%Cu-25%Ni; (d) 4×4 model, 25%Cu-75%Ni; (e) 4×4 model, 50%Cu-50%Ni; (f) 4×4 model, 75%Cu-25%Ni

Fig. 11. Results after relaxation. (a) Local stress distributions; (b) microstructures

Fig. 12. Relationship between pressure and relative density of Cu/Ni composite particles. (a) 2×2 model; (b) 4×4 model

Fig. 13. Lattice number proportions. (a) 25%Cu-75%Ni; (b) 75%Cu-25%Ni

Fig. 14. Lattices and dislocations of Cu/Ni composite particles at 300 ps in 2×2 model. (a) Lattices of mixed 25%Cu-75%Ni; (b) dislocations of mixed 25%Cu-75%Ni; (c) lattices of mixed 75%Cu-25%Ni; (d) dislocations of mixed 75%Cu-25%Ni

Fig. 15. System temperature

Fig. 16. Temperature distributions of mixed 75%Cu-25%Ni at different compaction time in 2×2 model. (a) 0 ps; (b) 300 ps