scholarly journals Investigation of the Subsurface Temperature Effects on Nanocutting Processes via Molecular Dynamics Simulations

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1220
Author(s):  
Michail Papanikolaou ◽  
Francisco Rodriguez Hernandez ◽  
Konstantinos Salonitis

In this investigation, three-dimensional molecular dynamics simulations have been performed in order to investigate the effects of the workpiece subsurface temperature on various nanocutting process parameters including cutting forces, friction coefficient, as well as the distribution of temperature and equivalent Von Mises stress at the subsurface. The simulation domain consists of a tool with a negative rake angle made of diamond and a workpiece made of copper. The grinding speed was considered equal to 100 m/s, while the depth of cut was set to 2 nm. The obtained results suggest that the subsurface temperature significantly affects all of the aforementioned nanocutting process parameters. More specifically, it has been numerically validated that, for high subsurface temperature values, thermal softening becomes dominant and this results in the reduction of the cutting forces. Finally, the dependency of local properties of the workpiece material, such as thermal conductivity and residual stresses on the subsurface temperature has been captured using numerical simulations for the first time to the authors’ best knowledge.

2021 ◽  
Vol 94 (7) ◽  
Author(s):  
Karina E. Avila ◽  
Vardan Hoviki Vardanyan ◽  
Herbert M. Urbassek

Abstract Cutting of metallic glasses produces as a rule serrated and segmented chips in experiments, while atomistic simulations produce straight unserrated chips. We demonstrate here that with increasing depth of cut – with all other parameters unchanged – chip serration starts to affect the morphology of the chip also in molecular dynamics simulations. The underlying reason is the shear localization in shear bands. As the distance between shear bands increases with increasing depth of cut, the surface morphology of the chip becomes increasingly segmented. The parallel shear bands that formed during cutting do no longer interact with each other when their separation is $$\gtrsim $$ ≳ 10 nm. Our results are analogous to the so-called fold instability that has been found when machining nanocrystalline metals. Graphic abstract


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