Molecular origin of hardening effect 

Weifu Sun*, Pengwan Chen

State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing, 100081, P. R. China  

Adv. Mater. Lett., 2019, 10 (2), pp 112-115

DOI: 10.5185/amlett.2019.2187

Publication Date (Web): Dec 19, 2018



Hardening effect is often observed in either experiments or simulations. And several continuum models or semi-empirical theories have been proposed to explain the origin, such as constraint-counting theory, the bond-order-length-strength (BOLS) correlation mechanism, equations of state-Murnaghan relationship, etc. However, the validity of these models or theories at the nanoscale have not been tested. In this work, high-speed head-on impact between silicon nanoparticles were studied using molecular dynamics (MD) simulations and their contact mechanics behaviours including contact force versus nominal displacement relationship were explored and the pronounced hardening effect was clearly observed. That’s, apparent Young’s modulus yielded is much higher than that of their bulk materials. The structure of silicon nanoparticles after compression was analysed in terms of bond length, bond angle, coordination number. The three existing relevant models were separately examined. The results show that any single of the three known theories cannot explain the higher elastic modulus obtained in present MD simulation. Probably, the three aspects contribute together to the hardening effect. This area awaits much more mature theory to explain the hardening effect under the influence of the dynamic effect.


Hardening effect, molecular simulation, continuum model.

Current Issue
The Journey of a Decade to Advancing Materials
Are the Electrospun Polymers Polymeric Fibers?
Mechanical and Thermal Properties of Composite Material and Insulation for a Single Walled Tank for Cryogenic Liquids
Prediction of Long-Term Behavior for Dynamically Loaded TPU
Investigation of Doped Titanium Dioxide in Anatase Phase. Study ab initio using Density Functional Theory
Comparison between Single Al2O3 or HfO2 Single Dielectric Layers and their Nanolaminated Systems
Preparation of Stable and Optimized Antibody-gold Nanoparticle Conjugates for Point of Care Test Immunoassays
Resonance-Based Temperature Sensors using a Wafer Level Vacuum Packaged SOI MEMS Process
Integrated System Based on the Hall Sensors Incorporating Compensation of the Distortions
The Efficacy of Cinnamomum Tamala as a Potential Antimicrobial Substance against the Multi-Drug Resistant Enterococcus Faecalis from Clinical Isolates
The Effect of Complexing Reagent on Structural, Electrical and Optical Properties of CuS Thin Film
Laser Cladding of Fluorapatite Nanopowders on Ti6Al4V
Preparation and Evaluation of Sulfonate Polyethylene Glycol Borate Ester as a Modifier of Functional Properties of Complex Petroleum Lithium Grease

Upcoming Congress

Knowledge Experience at Sea TM