论文标题
4D茎弹性应力状态表征的twip钢Nanotwin
4D-STEM elastic stress state characterisation of a TWIP steel nanotwin
论文作者
论文摘要
我们测量了双胞胎诱导的可塑性（TIP）钢中变形纳米温的应力状态。使用四维扫描透射电子显微镜（4D-STEM），我们在68.2 x-83.1 nm感兴趣的面积中测量弹性应变场，扫描步骤为0.36 nm，衍射极限分辨率为0.73 nm。双胞胎中和周围的应力场与分析理论所期望的形式相匹配，并且按15 GPA的顺序接近材料的理论强度。我们推断，测得的后压力限制双重增厚，这为为什么在变形过程中旋转钢双胞胎保持薄，不断分裂谷物以进行大量工作硬化。我们的结果支持现代机械理解对孪生对裂纹钢中裂纹繁殖和覆盖的影响的理解。
We measure the stress state in and around a deformation nanotwin in a twinning-induced plasticity (TWIP) steel. Using four-dimensional scanning transmission electron microscopy (4D-STEM), we measure the elastic strain field in a 68.2-by-83.1 nm area of interest with a scan step of 0.36 nm and a diffraction limit resolution of 0.73 nm. The stress field in and surrounding the twin matches the form expected from analytical theory and is on the order of 15 GPa, close to the theoretical strength of the material. We infer that the measured back-stress limits twin thickening, providing a rationale for why TWIP steel twins remain thin during deformation, continuously dividing grains to give substantial work hardening. Our results support modern mechanistic understanding of the influence of twinning on crack propagation and embrittlement in TWIP steels.
