Fig. 1. Schematic of CLP

Fig. 2. Schematic of LP and sample size. (a) Square sample; (b) tensile sample

Fig. 3. Micro-hardness at positons with different distances from surface

Fig. 4. Cross-sectional grain structures of CLP samples along depth direction. (a) SPD layer; (b) MPD layer; (c) substrate

Fig. 5. Strength and average elongation of different samples

Fig. 6. (a) Fracture morphology of RTLP sample; (b) fracture morphology of CLP sample; (c) EDS at position with red cross mark

Fig. 7. Schematic of aluminum alloy dimple fracture