Title: Molecular dynamic study of combined effects of diamond tool rake angle and d_uncut/R_edge ratio on nanomachining behaviour of monocrystalline optical silicon

Authors: Lukman N. Abdulkadir; Khaled Abou-El-Hossein; Muhammad Mukhtar Liman; Odedeyi Peter Babatunde; Abubakar Ishaq Jumare

Addresses: Precision Engineering Laboratory, Nelson Mandela University, South Africa ' Precision Engineering Laboratory, Nelson Mandela University, South Africa ' Precision Engineering Laboratory, Nelson Mandela University, South Africa ' Precision Engineering Laboratory, Nelson Mandela University, South Africa ' Precision Engineering Laboratory, Nelson Mandela University, South Africa

Abstract: Molecular dynamics (MD) of silicon ductility under contact loading due to the influence of edge radius, rake angle and undeformed (uncut) chip thickness to edge radius ratio was studied. The study showed that the stress state of silicon increased with increase in rake angle and decrease in undeformed chip thickness to edge radius ratio. Larger rake angle tool experienced stronger cutting resistance from the workpiece than the smaller rake angle, causing the specific cutting energy (SCE), cutting and thrust forces to increase. There was high kinetic friction at high undeformed chip thickness to edge radius ratio, reducing as the rake angle increases due to increase in thrust forces. The excessive negative effective rake angle at low undeformed chip thickness to edge radius ratio and high rake angle seems to be responsible for increase in phase change at the cutting region, decrease in chip length and thickness, increase in subsurface deformation.

Keywords: molecular dynamics; potential function; optical silicon; rake angle; undeformed chip thickness to edge radius ratio; plastic deformation; subsurface deformation.

DOI: 10.1504/IJCMSSE.2019.104700

International Journal of Computational Materials Science and Surface Engineering, 2019 Vol.8 No.3/4, pp.245 - 268

Received: 10 Jan 2019
Accepted: 05 Aug 2019
Published online: 28 Jan 2020 *

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