In-situ DIC characterization of dislocation density and stored strain energy fields for deformation zones during cutting of Ti6Al4V alloy

Abstract

Cutting deformation behaviors at the microscale are important evidence for understanding fundamental cutting mechanisms. However, characterizing the microstructure of materials during the high-speed cutting process within narrow deformation zones presents significant challenges. In this work, a characterization methodology based on the digital image correlation (DIC) technique was developed to determine the microstructure evolution within the cutting deformation zones. High-speed in-situ visible and infrared image acquisition systems were utilized to capture gray and infrared image sequences during orthogonal cutting of Ti6Al4V. A deformation field reconstruction method based on the dislocation-density based (DDB) model was developed to derive the total dislocation density fields. The stored strain energy fields were then determined based on dislocation density fields. The generation process of serrated chips was investigated from macroscopic and microscopic perspectives to reveal the material removal mechanism during machining. This work provides a novel characterization methodology for investigating microstructure evolution under dynamic deformation conditions.