TY - GEN
T1 - Self-healing of cracks during ductile regime machining of silicon
T2 - 16th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2016
AU - Goel, Saurav
AU - Stukowski, Alexander
AU - Kovalchenko, Andrii
AU - Cross, Graham
PY - 2016
Y1 - 2016
N2 - During nanoindentation and ductile-regime machining of silicon, a phenomenon known as "self-healing" takes place in that the microcracks, microfractures, and small spallings generated during the machining are filled by the plastically flowing ductile phase of silicon. However, this phenomenon has not been observed in simulation studies. In this work, using a long-range potential function, molecular dynamics simulation was used to provide an improved explanation of this mechanism. A unique phenomenon of brittle cracking was discovered, typically inclined at an angle of 45° to 55° to the cut surface, leading to the formation of periodic arrays of nanogrooves being filled by plastically flowing silicon during cutting. This observation is supported by the direct imaging. The simulated X-ray diffraction analysis proves that in contrast to experiments, Si-I to Si-II (beta tin) transformation during ductile-regime cutting is highly unlikely and solid-state amorphisation of silicon caused solely by the machining stress rather than the cutting temperature is the key to its brittle-ductile transition observed during the MD simulations.
AB - During nanoindentation and ductile-regime machining of silicon, a phenomenon known as "self-healing" takes place in that the microcracks, microfractures, and small spallings generated during the machining are filled by the plastically flowing ductile phase of silicon. However, this phenomenon has not been observed in simulation studies. In this work, using a long-range potential function, molecular dynamics simulation was used to provide an improved explanation of this mechanism. A unique phenomenon of brittle cracking was discovered, typically inclined at an angle of 45° to 55° to the cut surface, leading to the formation of periodic arrays of nanogrooves being filled by plastically flowing silicon during cutting. This observation is supported by the direct imaging. The simulated X-ray diffraction analysis proves that in contrast to experiments, Si-I to Si-II (beta tin) transformation during ductile-regime cutting is highly unlikely and solid-state amorphisation of silicon caused solely by the machining stress rather than the cutting temperature is the key to its brittle-ductile transition observed during the MD simulations.
KW - Diamond machining
KW - Ductile-regime cutting
KW - High pressure phase transformation
KW - MD simulation
KW - Silicon
UR - http://www.scopus.com/inward/record.url?scp=84984598872&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84984598872
T3 - Proceedings of the 16th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2016
BT - Proceedings of the 16th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2016
A2 - Bointon, P.
A2 - Leach, Richard
A2 - Southon, N.
PB - euspen
Y2 - 30 May 2016 through 3 June 2016
ER -