Comparative Analysis of Microstrain and Dislocation in CoCrFeMnNi and CoCrFeMnNiTi High Entropy Alloys

Abstract

Microstrain and dislocation density are critical determinants affecting crystalline materials’ mechanical and physical properties. This investigation assesses the changes present in CoCrFeMnNi and CoCrFeMnNiTi high-entropy alloys (HEAs) through the application of X-ray diffraction (XRD) and the Williamson-Hall method for microstrain and dislocation density. Field Emission Scanning Electron Microscope (FESEM) is used for microstructure analysis. It is observed that the transition from the face-centered cubic (FCC) to body-centered cubic (BCC) phase from CoCrFeMnNi to CoCrFeMnNiTi HEA results in a significant shift of the peak towards a lower 2θ angle by 0.62°. A 30% reduction in microstrain and a 17.49% decrease in dislocation density were noted with the addition of titanium (Ti), which correlated to an increase in hardness measurement of 952 ± 5 HV in CoCrFeMnNiTi. The results indicate the role of Ti in defect dynamics, which is crucial for optimizing material properties.