[2019-12-26]Lecture Prof.Zhang Xiaodan, Hierarchical Structure and Strengthening Mechanisms in Pearlitic Steel Wire
Lecture: Hierarchical Structure and Strengthening Mechanisms in Pearlitic Steel Wire
Speaker：Prof. Zhang Xiaodan
Time: 9:30-12:00AM, Dec. 26th, 2019
Location: 210 meeting room, MSE building
ABSTRACT:
Microstructure evolution and strengthening mechanisms have been analyzed in a cold-drawn pearlitic steel wire (the strongest engineering materials in the world) with a nanostructure down to 10 nm and a flow stress up to 5.4 GPa.
The interlamellar spacing and the cementite lamellae thickness are reduced during drawing in accordance with the change in wire diameter up to a strain of 2.5. At a higher strain enhanced thinning of cementite lamellae points to decomposition and carbon enrichment of the ferrite lamellae. Dislocations are stored as individual dislocations and in low angle boundaries. No saturation in the dislocation density is observed and it increases to 5E16 m-2 at a strain of 5.4. A high dislocation density at the ferrite/cementite(ferrite) interface is also observed. Boundary strengthening, dislocation strengthening and solid solution hardening are suggested and good agreement is found between the calculated flow stresses and experimental values.
CV
个人经历：
2009年 清华大学材料科学与工程系 工程博士
2002年 中南大学材料科学与工程系 工学学士
任职经历：
2018年至今 丹麦技术大学机械工程系 高级研究员
2016年05月- 2017年12月 丹麦科技大学风能系 高级研究员
2012年06月- 2016年04月 丹麦科技大学风能系 研究员
2012年01月- 2012年05月 丹麦科技大学风能系 博士后
2009年08月- 2011年12月 丹麦Risø实验室材料研究部 博士后
研究领域：异构组织的形成及其热力学响应；机械和化学表面优化；电子显微镜中的原位/非原位力学测试；金属微观结构-性能关系；金属零件的失效分析。
