Study on micro-crack propagation mechanism in different positions of single crystal titanium at nanoscale

Abstract

In order to study the nanoscale mechanism of micro-crack propagation at different positions in single-crystal titanium, a molecular dynamics model of single-crystal titanium was established to analyze the micro-crack propagation behavior at different locations and to explore the influence of crack position on the expansion. The nanoscale mechanism of micro-crack propagation in single-crystal titanium is revealed. The simulation results show that the edge crack instability and expansion gradually form a gap under the tensile load in [12–30] crystal direction. However, the gap and absorption energy could be higher, making the morphology change at the gap not obvious. When the tensile load of the [0001] crystal orientation reaches the yield strength of the material, the material will plastically flow, making the model's overall shape symmetric and uniform. The tensile load has no excitation effect on the upright micro-crack. The upper crack is dominant when the single-crystal titanium model is preloaded with parallel double cracks. It expands to form holes, inhibiting the lower crack's growth.