The Modulation of Compositional Heterogeneity for Controlling Shear Banding in Co-P Metallic Nanoglasses

Area of Science:

• Materials Science
• Nanotechnology
• Computational Materials Science

Background:

• Shear banding in metallic nanoglasses (NGs) is critically influenced by glass-glass interfaces (GGIs).
• The precise role of the GGI phase in controlling shear banding remains incompletely understood.
• Developing strategies to engineer GGIs is essential for enhancing NG mechanical properties.

Purpose of the Study:

• To investigate elemental segregation at GGIs in Cobalt-Phosphorus (Co-P) nanoglasses.
• To elucidate the atomic structure and properties of GGIs formed by elemental segregation.
• To understand how GGI phase composition and structure influence shear banding and ductility in NGs.

Main Methods:

• Molecular dynamics simulations were employed to study Co-P nanoglasses.
• Analysis focused on the GGI regions, particularly the phenomenon of elemental segregation.
• Atomic structures and density variations within GGIs were examined.

Main Results:

• Elemental segregation, specifically Cobalt (Co) enrichment, was observed in the GGI regions of Co-P NGs.
• Segregated GGIs exhibited lower atomic density compared to the bulk glassy grains.
• Co segregation was found to reduce the shear resistance of GGIs.
• Enhanced Co segregation in GGIs significantly altered shear banding behavior, improving NGs' ductility.

Conclusions:

• Elemental segregation is a key factor in forming the GGI phase in NGs.
• The reduced shear resistance of Co-enriched GGIs promotes shear banding and enhances ductility.
• This research provides insights into GGI engineering for improving the mechanical performance of nanoglasses.