Experimental Quantification of Resolved Shear Stresses for Dislocation Motion in TiN

Area of Science:

• Materials Science
• Mechanical Engineering
• Nanotechnology

Background:

• Quantifying critical resolved shear stress (CRSS) for unit dislocation glide remains a significant experimental challenge.
• Understanding dislocation behavior is crucial for predicting mechanical properties of materials.
• High-strength materials like TiN require precise characterization of deformation mechanisms.

Purpose of the Study:

• To experimentally quantify the CRSS for individual dislocation motion on the {110}⟨011⟩ slip system in TiN.
• To measure the CRSS associated with glide dislocation re-emission from a tilt grain boundary in TiN.
• To develop and demonstrate an in situ approach for measuring local stresses during dislocation motion in advanced materials.

Main Methods:

• In situ nanoindentation performed within a high-resolution transmission electron microscope (HRTEM).
• Advanced strain analysis of structural images captured during the in situ experiments.
• Direct quantification of stresses at the unit dislocation level.

Main Results:

• The CRSS for dislocation motion on the {110}⟨011⟩ slip system in TiN was experimentally determined.
• The CRSS for dislocation re-emission from a tilt grain boundary in TiN was quantified.
• The study successfully demonstrated the feasibility of measuring local stresses driving dislocation movement.

Conclusions:

• This work provides a novel experimental approach to measure CRSS at the unit dislocation level.
• The developed method is applicable to understanding deformation mechanisms in high-strength materials.
• The findings contribute to a more accurate prediction of material behavior under stress.