Fig. 8

The detrended curves of Al (a), Young’s modulus and hardness at 200 mN and 50 mN (b-e) of line I-I’ in Fig. 2. The blue line in (a) represents ~ 3.57 mm cycle and was extracted from the detrended Al series with a bandpass of 0.28 ± 0.08 cycles/mm; the red lines represent 1.2–0.6 mm cycles and were extracted from the detrended series with a bandpass of 1.0 ± 0.05 cycles/mm in ( a),1.2 ± 0.1 cycles/mm in (b), 1.6 ± 0.1 cycles/mm in (c), 1.0 ± 0.04 cycles/mm in (d), and 0.96 ± 0.04 cycles/mm in (e).