<110> dislocation junction formation via the coalescence between nanoscale 1/2<111> prismatic dislocation loops in iron

Abstract

Accurate knowledge of dislocation reactions is crucial for understanding and controlling the macroscopic mechanical properties of α-iron and its alloys. A dislocation reaction: 1/2[111]+1/2[11 1]→[110] has never been observed. However, using in-situ transmission electron microscopy, we demonstrate that the two nanoscale 1/2<111> prismatic dislocation loops that undergo 1D glide motion approach and collide with each other to form a "high-energy" [110]-dislocation junction. This anomalous reaction cannot be understood within the framework of the elasticity.