Atomistic simulation of 0001〈 1 2 1 0〉 crack propagation with Nb precipitates in α-Zr

The fracture characteristics of Zr alloys significantly impact the performance of fuel cladding tubes in pressurized water reactors of nuclear power plants. In this study, molecular dynamics (MD) simulations were performed to investigate the 0001〈 1210 〉 crack propagation in α-Zr. The influence of temperature and Nb precipitates on the crack propagation was investigated. A total of 469 tensile simulations were conducted. An innovative approach to study the interaction between crack propagation and second-phase particles in the crystals was adopted, which could effectively capture the interaction of second-phase particles with dislocations and twins generated during crack propagation. In the simulation, 11 26 〈11 21 〉 and 101 2〈10 11 〉 twins were observed during crack propagation with Nb precipitates in the matrix. The simulation results revealed that the Nb precipitates further resisted crack propagation, especially those with a radius of approximately 2 nm. In addition, the Nb precipitates in the extension direction of the 1126 〈 1121 〉 twin exhibited higher resistance to crack propagation than those at other locations. Graphical Abstract