Atomistic simulations of shock-induced phase transformations in polycrystalline iron

TY - GEN

T1 - Atomistic simulations of shock-induced phase transformations in polycrystalline iron

AU - Kadau, Kai

AU - Germann, Timothy C.

AU - Lomdahl, Peter S.

AU - Albers, Robert C.

AU - Wark, Justin S.

AU - Higginbotham, Andrew

AU - Holian, Brad Lee

PY - 2007/12/1

Y1 - 2007/12/1

N2 - We report on large-scale non-equilibrium atomistic simulations of shock-induced transformations in poly crystalline iron samples. These simulations show that, depending on the crystallographic orientation of the body-centered-cubic (bcc) parent phase grains with respect to the shock direction, a significant fraction of the product phase can be face-centered-cubic (fcc) instead of the expected hexagonal-close-packed (hcp) structure. This observation is explained by the existence of different transformation mechanisms for shocks along different crystallographic directions. We conclude that the observation of different product phases can be explained by simple geometric considerations of the involved transformation mechanisms between the parent bcc structure and the product hcp and fcc structures. Ultrafast high-energy laser-based experiments are underway to further investigate this subject.

AB - We report on large-scale non-equilibrium atomistic simulations of shock-induced transformations in poly crystalline iron samples. These simulations show that, depending on the crystallographic orientation of the body-centered-cubic (bcc) parent phase grains with respect to the shock direction, a significant fraction of the product phase can be face-centered-cubic (fcc) instead of the expected hexagonal-close-packed (hcp) structure. This observation is explained by the existence of different transformation mechanisms for shocks along different crystallographic directions. We conclude that the observation of different product phases can be explained by simple geometric considerations of the involved transformation mechanisms between the parent bcc structure and the product hcp and fcc structures. Ultrafast high-energy laser-based experiments are underway to further investigate this subject.

KW - Embedded atom method

KW - Iron

KW - Molecular dynamics

KW - Polycrystal

KW - Shock

UR - http://www.scopus.com/inward/record.url?scp=71849104291&partnerID=8YFLogxK

U2 - 10.1063/1.2833039

DO - 10.1063/1.2833039

M3 - Conference contribution

AN - SCOPUS:71849104291

SN - 9780735404694

VL - 955

SP - 313

EP - 316

BT - AIP Conference Proceedings

T2 - 15th Biennial International Conference of the APS Topical Group on Shock Compression of Condensed Matter, SCCM 2007

Y2 - 24 June 2007 through 29 June 2007

ER -