2019/02/04 by William C. Tucker, Tucker, William C., Adrienne Dove +3 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #Computational Physics (physics.comp-ph) #FOS: Physical sciences #Force Microscopy Techniques and Applications #Granular flow and fluidized beds #Material Dynamics and Properties #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.1902.01250
openalex publication_date 2019/02/04 · openalex created_date 2022/07/29 · openalex updated_date 2026/07/28
Collisions between amorphous Fe nanoparticles were studied using\nmolecular-dynamics simulation. For head-on collisions of nanoparticles with\nradii R = 1.4 nm, R = 5.2 nm, and R = 11 nm, sticking was observed at all\nsimulated velocities. The results were compared to the description provided by\nthe JKR model. It was found that strong disagreement exists between the\npredictions of JKR and the results of the molecular-dynamics simulation due to\nthe presence of additional dissipative processes which strengthen sticking\nbehavior. First, it is demonstrated that very strong dissipation into atomic\nvibrations occurs during the collision. The dissipation is strong enough to\nprevent significant rebound of the nanoparticles. Additionally, the morphology\nof the adhered nanoparticles includes a ``neck'' that increases in radius with\nincreasing collision velocity which results in amplified irreversibility and\nadhesion. Approximate calculation of the stress during the collision indicates\nthat stress levels are well above typical yield stress values even for low\nvelocity collisions, consistent with the observation of plastic deformation.\nFurthermore, it is shown that for nanoparticles with R \≤ 11 nm, the\ndominance of surface attraction results in large effective collision velocities\nand plastic deformation. By obtaining scaling relations for computed\nquantities, predictions are made for larger nanoparticles up to R \∼ 1\n\μm. This work provides a new perspective on collisional dissipation and\nadhesion with an important connection to the modern understanding of tribology\nand friction.\n