报告摘要：
To control and understand strength and ductility of materials is always one of the most important issues for materials sciences, not only for practical applications but also for fundamental sciences. This talk will survey two types of strengthening ways: extra-electron induced covalent strengthening in quasicrystal-related aluminides and oxygen-enriched nanoparticle dispersion-strengthening in ODS steels for advanced fusion reactors. In the first case, we will represent the mechanism as to why the substantial strengthening and intrinsic brittleness occur in the quasicyrstal-related Al12W-type aluminides and its theoretical implication to the new model of predicting hardness of materials. In the second case, we will focus on the physical origins of the stability and irradiation-resistant applications of ODS steels. Under ultrasevere irradiation from nuclear fission and fusion reactors, conventional structural steels fail to resist the growth and void swelling of the He-bubble and hydrogen-cluster trapped by the Fe vacancies, resulting in the damage occurrence, such as fast fracture, embirttlement and degradation of creep strengths. The interaction details among helium (He), hydrogen (H) and oxygen (O) as well as additional alloying elements in ODS steels will be represented in details. Our results show that the oxygen-enriched nanoparticles play the crucial role to prohibit the growth and viod swelling of the He/H-bubbles in ODS Fe matrix.

报告人简介
Chen XingQiu is a research staff member funded by a CAS 'Hundred Talent Project' at Shenyang National Laboratory for Materials Sciences, Institute of Metal Research. Chen received his B. & M. Sc in Metallurgy from Northeastern University, China and his Ph.D degree in the Vienna Center for Computational Materials Science (CMS) and in the Institute of Physical Chemistry in the University of Vienna, Austria. In 2007, he moved to the Oak Ridge National Laboratory in USA for his three-year postdoctoral studies in the Materials Science and Technology Division. He has published over 40 peer-reviewed papers including 1 Nature Chemistry, 6 PRL and 1 Adv. Mater. His research mainly focuses on the first-principles calculation studies of high-performance structural materials and correlated electron systems.