Evolution of dislocation and twin structures in Ti3Al during solidification

Abstract

Dislocation and twin structures often found in many metal alloys significantly affect their mechanical properties. However, observing the evolution processes of dislocation and twin structures using traditional experimental methods is challenging. In this paper, molecular dynamics was used to study the formation mechanism of dislocation and twin structures in Ti3Al during rapid solidification. Two microstructure types were obtained: nanocrystalline, composed of multiple grains, and lamellar. The lamellar structure is dominated by stacking fault and coherent twin boundary. According to the synthesis and decomposition of different types of dislocations, the formation and evolution of crystal defects under different models are analyzed. This provides a reference for understanding the mechanical properties of Ti3Al alloys with different microstructures.