Plastic Deformation Modes of CuZr/Cu Multilayers.

Area of Science:

• Materials Science
• Mechanical Engineering
• Nanotechnology

Background:

• Multilayer materials offer tunable mechanical properties.
• Understanding deformation mechanisms in nanostructured alloys is crucial for advanced applications.

Purpose of the Study:

• To investigate the influence of CuZr layer thickness on plastic deformation modes in CuZr/Cu multilayers.
• To elucidate the underlying mechanisms of plastic co-deformation and shear instability.

Main Methods:

• Synthesis of CuZr/Cu multilayered thin films with varying CuZr layer thicknesses (4-100 nm) and fixed Cu layer thickness (18 nm).
• Nanoindentation testing to probe mechanical response and deformation behavior.
• Microscopic analysis to characterize deformation modes and microstructural evolution.

Main Results:

• Continuous plastic co-deformation observed in multilayers with thin CuZr layers (4 nm and 10 nm).
• Plastic-induced shear instability observed in multilayers with thick CuZr layers (>20 nm).
• Co-deformation attributed to shear transformation zones at interfaces; instability linked to shear band nucleation and propagation.

Conclusions:

• CuZr layer thickness critically controls the plastic deformation mechanisms in CuZr/Cu multilayers.
• Shear bands initiate in CuZr layers and propagate into Cu layers, influenced by crystallographic constraints.
• The study provides insights into designing nanostructured materials with tailored mechanical properties.