TY - JOUR AU - Megumi Kawasaki DA - 2014/11 PY - 2014 UR - https://www.cambridge.org/core/journals/journal-of-materials-research/article/critical-examination-of-the-paradox-of-strength-and-ductility-in-ultrafinegrained-metals/B03B4A66C203AF6353F17F96E98FC8BD UR - http://hdl.handle.net/20.500.11754/53220 AB - The paradox of strength and ductility is now well established and denotes the difficulty of simultaneously achieving both high strength and high ductility. This paradox was critically examined using a cast Al-7% Si alloy processed by high-pressure torsion (HPT) for up to 10 turns at a temperature of either 298 or 445 K. This processing reduces the grain size to a minimum of similar to 0.4 mu m and also decreases the average size of the Si particles. The results show that samples processed to high numbers of HPT turns exhibit both high strength and high ductility when tested at relatively low strain rates and the strain rate sensitivity under these conditions is similar to 0.14 which suggests that flow occurs by some limited grain boundary sliding and crystallographic slip. The results are also displayed on the traditional diagram for strength and ductility and they demonstrate the potential for achieving high strength and high ductility by increasing the number of turns in HPT. PB - Cambridge University Press KW - Al–Si alloy KW - ductility KW - high-pressure torsion KW - strength KW - ultrafine grains TI - A critical examination of the paradox of strength and ductility in ultrafine-grained metals VL - 29 DO - 10.1557/jmr.2014.272 T2 - JOURNAL OF MATERIALS RESEARCH ER -