Deformation of interface dominated multiphase materials

Deep Choudhuri

New Mexico Institute of Mining and Technology

Multicomponent high entropyalloys were originally designed to form a single-phase solid solution. However, several recent studies have shown that positive enthalpy effects, i.e. attraction between dissimilar atoms, lead to the formation of various intermetallic compound (IMC) phases. Here, we will present results from a promising IMC-reinforced HEA microstructure that comprises of fcc-matrix and bcc-ordered B2 IMC. The structure of fcc/B2 semicoherent Kurdjumov-Sachs (KS) interface was rigorously determined by coupling molecular dynamics (MD) simulations, TEM and electron-backscattered diffraction (EBSD). Furthermore, MD simulations, involving the deformation of near-realistic fcc-B2 microstructures, were conducted to reveal the role of KS interface on deformation mechanisms. These simulations established a direct relationship between the structural features in the KS interface and deformation processes like twin formation within fcc phase, fcc-to-B2 slip transfer and fcc/B2 interfacial strain accumulation.