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Bioinorganic Chemistry and Applications
Volume 2011, Article ID 173782, 13 pages
http://dx.doi.org/10.1155/2011/173782
Research Article

Dynamic Mechanical Response of Biomedical 316L Stainless Steel as Function of Strain Rate and Temperature

1Department of Mechanical Engineering, National Cheng Kung University, Tainan 701, Taiwan
2Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan
3National Center for High-Performance Computing, Hsin-Shi Tainan 744, Taiwan

Received 30 June 2011; Revised 19 September 2011; Accepted 19 September 2011

Academic Editor: Concepción López

Copyright © 2011 Woei-Shyan Lee et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A split Hopkinson pressure bar is used to investigate the dynamic mechanical properties of biomedical 316L stainless steel under strain rates ranging from 1 × 103 s-1 to 5 × 103 s-1 and temperatures between 25C and 800C. The results indicate that the flow stress, work-hardening rate, strain rate sensitivity, and thermal activation energy are all significantly dependent on the strain, strain rate, and temperature. For a constant temperature, the flow stress, work-hardening rate, and strain rate sensitivity increase with increasing strain rate, while the thermal activation energy decreases. Catastrophic failure occurs only for the specimens deformed at a strain rate of 5 × 103 s-1 and temperatures of 25C or 200C. Scanning electron microscopy observations show that the specimens fracture in a ductile shear mode. Optical microscopy analyses reveal that the number of slip bands within the grains increases with an increasing strain rate. Moreover, a dynamic recrystallisation of the deformed microstructure is observed in the specimens tested at the highest temperature of 800C.