Single-mechanism rate theory for dynamic strain aging in fcc metals

✍ Scribed by M.A. Soare; W.A. Curtin

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 370 KB
• Volume: 56
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2008.04.030

✦ Synopsis

A full thermal activation rate theory for dynamic strain aging is developed for the case where a single rate dependent strengthening mechanism controls dislocation motion in a material (e.g. solute diffusion). The analysis shows that negative strain-rate sensitivity (SRS) cannot be obtained within such a framework, a conclusion previously reached by Ha ¨hner [Ha ¨hner P. Mater Sci Eng A 1996;207:208]. However, the SRS can be greatly reduced over a range of strain rates, making the inverse behavior more accessible by other mechanisms. In addition, the aging mechanism naturally gives rise to an instantaneous positive SRS and stress relaxation behavior under strain-rate jump conditions, putting the concepts advanced by McCormick [