Molecular dynamics study on the influence of loading mode on deformation behavior of Ni/Al nano-laminated composite

Abstract Molecular dynamics investigated the influence of loading mode on deformation behavior of Ni/Al nano-laminated composite. Mechanical properties are significantly dependent on the angles between loading axis and heterogeneous interface. Yield strength of inclined sample is the lowest, but yield strain is the highest. Tensile strength of parallel sample with lowest angle is the highest, and that of samples with higher angle is significantly lower. Inclined sample has moderate tensile strength and the highest tensile ductility. In samples with higher angle, lattice dislocations explosively nucleate in softer layer around interface, while in samples with lower angle, they nucleate at interface nodes. Interface in samples with higher angle has stronger hindering effect on continuous sliding of dislocation through interface than that in samples with lower angle. Stress component along sliding direction on slip plane and the angle between sliding direction of activated dislocation and the direction interfacial misfit dislocation line well quantify the activation of slip system and damage of heterogeneous interface, respectively. Total dislocation density in sample with higher angle is higher among all samples. Furthermore, density peak value of stair-rod dislocation in samples with higher angle is the highest, density peak values of Frank and Hirth dislocations in samples with lower angle are the highest. In samples with higher angle, voids first appear in the slice of Al layer below interface, voids originate from the junction point among three activated slip planes, and void morphologies present sphere-like. In samples with lower angle, voids first appear in the slice of interface, voids originate from the interaction position between lattice dislocations and interfacial misfit dislocations, and void morphology presents strip-like.