Unusual plasticity and strength of metals at ultra-short load durations
V.E. Fortova aJoint Institute for High Temperatures, Russian Academy of Sciences, ul. Izhorskaya 13/19, Moscow, 127412, Russian Federation bBen-Gurion University of the Negev, PO Box 653, Beer-Sheva, Negev, 8410501, Israel cInstitute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region, Russian Federation
This paper briefly reviews recent results on the rate-temperature dependence of flow stresses and fracture stresses in metals under high strain rate conditions for pulsed shock-wave loads with durations from tens of picoseconds up to microseconds. In the experiments, an approaching to ultimate ("ideal") values of the shear and tensile strength has been realized and anomalous growth of the yield stress with the temperature at high strain rate has been confirmed for some metals. New evidence is obtained for the intense onset of dislocation multiplication immediately in the elastic precursor wave. It is found that under these conditions inclusions and other strengthening factors may reduce the dynamic yield stress. Novel and unexpected features are observed in the evolution of elastic-plastic shock compression waves.
Keywords: shock waves in solids, high-rate deformation, the high-rate fracture, dynamics of dislocations, ideal strength, anomalous thermal hardening, polycrystalline metals and single crystals PACS:62.50.−p DOI:10.3367/UFNe.2016.12.038004 URL: https://ufn.ru/en/articles/2017/5/c/ Citation: Kanel G I, Zaretsky E B, Razorenov S V, Ashitkov S I, Fortov V E "Unusual plasticity and strength of metals at ultra-short load durations" Phys. Usp.60 490–508 (2017)