Time-resolved Laue diffraction of deforming micropillars.

Area of Science:

• Materials Science
• Solid Mechanics
• Crystallography

Background:

• Understanding crystal plasticity is crucial for materials engineering.
• Micron-sized single crystals offer a controlled system to study fundamental deformation mechanisms.
• Focused ion beam milling enables precise fabrication of micro-scale specimens.

Purpose of the Study:

• To investigate the dynamic correlation between microstructure evolution and plasticity in gold (Au) single crystals.
• To reveal the mechanisms of crystal rotation and strengthening during mechanical loading.
• To understand the role of pre-existing strain gradients in selecting plastic deformation pathways.

Main Methods:

• Real-time resolved white beam Laue diffraction was employed.
• Micron-sized, focused ion beam (FIB) milled single crystal Au pillars were subjected to compression.
• Analysis of Laue pattern evolution to track crystal lattice changes.

Main Results:

• Observed real-time evolution of Laue patterns during pillar compression.
• Demonstrated occurrence of significant crystal rotation and strengthening.
• Identified plasticity initiation on a slip system not geometrically predicted.

Conclusions:

• Plasticity in Au pillars initiated on a specific slip system due to pre-existing strain gradients.
• The study reveals a dynamical correlation between microstructure and plasticity.
• Findings provide insights into the mechanical behavior of micro-scale crystalline materials.