图3.

具有梯度纳米晶粒结构表层纯Cu棒状样品的拉伸曲线^[3]及强度-拉伸均匀延伸率匹配

Fig.3.

Quasi-static tensile engineering stress-strain curves for the CG Cu bar sample with gauge diameter of 4.5 mm, the GNG/CG bar sample, and a free-standing GNG foil sample (the top 50-μm-thick layer was removed from the GNG/CG sample, gauge dimensions: 4 mm by 2 mm by 0.05 mm), respectively. Strain rate is 61×10^-4 s^-1. Inset shows the tensile GNG/CG bar sample before and after tension (with a normal strain of 30%) (a)^[3], and strength-tensile uniform elongation synergy (b) (CG—coarse-grained, GNG—gradient nano-grained)