J. Phys. IV France 10 (2000) Pr9-51-Pr9-56
Observation and modeling of dynamic recrystallization in high-strain, high-strain rate deformation of metalsM.A. Meyers1, V.F. Nesterenko1, J.C. LaSalvia2, Y.B. Xu3 and Q. Xue1
1 University of California, San Diego, Department of MAE, La Jolla, CA 92093, U.S.A.
2 U.S. Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, MD 21005, U.S.A.
3 Institute of Metals Research, Chinese Academy of Sciences, Shenyang, China
The microstructural evolution inside shear bands was investigated experimentally and analytically. A fine recrystallized structure (grains with 0.05-0.3 µm) is observed in Ti, Cu, 304 stainless steel, Al-Li, and Ta, and it is becoming clear that a recrystallization mechanism is operating. The fast deformation and short cooling times inhibit grain-boundary migration; it is shown that the time is not sufficient for migrational recrystallization. A rotational mechanism is proposed and presented in terms of dislocation energetics. This mechanism necessitates the stages of high dislocation generation and their organization into elongated cells. Upon continued deformation, the cells become sub-grains with significant misorientations. These elongated sub-grains break up into equiaxed grains with size of approximately 0.05-0.3 µm. It is shown that grain-boundary reorientation can operate within the time of the deformation process.
© EDP Sciences 2000