Grain boundary energy and relative ion damage: experimental observation and molecular dynamics simulation

Abstract

In large-grained (>1 mm grain size), high-purity (200 ppm of oxygen as major impurity), single-phase Zirconium: a combination of thermal grooving and molecular statics (MS) enabled measurements of γGB (grain boundary energy). Controlled focused ion beam damage, with Ga+ (galium) ions, provided a clear scaling between γGB and damage kinetics. The latter was obtained through direct observations on apparent grain boundary width by high-resolution electron backscattered diffraction. MS simulations were also used to create tilt boundaries of different γGB. Molecular dynamics, on the other hand, simulated grain boundary damage through Ga+ ion implantation. Simulations, capturing the momentum transfer, reproduced a qualitatively similar trend of γGB dependence of experimental ion damage.