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Experimental and Theoretical Investigation of Crystallographic Orientation Dependence of Nanoscratching of Single Crystalline Copper.

Geng Y, Zhang J, Yan Y, Yu B, Geng L, Sun T - PLoS ONE (2015)

Bottom Line: The correlation of microscopic deformation behavior of the material with macroscopically-observed machining results is revealed.Moreover, the influence of crystallographic orientation on the nanoscratching of single crystalline copper is examined.Both experiments and MD simulations demonstrate that the machined surface morphologies in terms of groove depth and surface pile-up exhibit strong crystallographic orientation dependence, because of different geometries of activated slip planes cutting with free surfaces and strain hardening abilities associated with different crystallographic orientations.

View Article: PubMed Central - PubMed

Affiliation: The State Key Laboratory of Robotics and Systems, Robotics Institute, Harbin Institute of Technology, Harbin, Heilongjiang, 150008, P. R. China; Center for Precision Engineering, Harbin Institute of Technology, Harbin, Heilongjiang, 150001, P. R. China.

ABSTRACT
In the present work, we perform experiments and molecular dynamics simulations to elucidate the underlying deformation mechanisms of single crystalline copper under the load-controlled multi-passes nanoscratching using a triangular pyramidal probe. The correlation of microscopic deformation behavior of the material with macroscopically-observed machining results is revealed. Moreover, the influence of crystallographic orientation on the nanoscratching of single crystalline copper is examined. Our simulation results indicate that the plastic deformation of single crystalline Cu under the nanoscratching is exclusively governed by dislocation mechanisms. However, there is no glissile dislocation structure formed due to the probe oscillation under the load-controlled mode. Both experiments and MD simulations demonstrate that the machined surface morphologies in terms of groove depth and surface pile-up exhibit strong crystallographic orientation dependence, because of different geometries of activated slip planes cutting with free surfaces and strain hardening abilities associated with different crystallographic orientations.

No MeSH data available.


Related in: MedlinePlus

Mechanical response during the load-controlled multi-passes nanoscratching of single crystalline Cu(010).(a) Increment of probe height-time curves and (b) Probe velocity-time curves during the penetration phase. (c) Increment of probe height-scratching length curves and (d) Scratching force-scratching length curves during the scratching phase.
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pone.0131886.g004: Mechanical response during the load-controlled multi-passes nanoscratching of single crystalline Cu(010).(a) Increment of probe height-time curves and (b) Probe velocity-time curves during the penetration phase. (c) Increment of probe height-scratching length curves and (d) Scratching force-scratching length curves during the scratching phase.

Mentions: Fig 4(A) and 4(B) plot the variations of the increment of probe height and velocity with time during the penetration phases of multi-passes nanoscratching of single crystalline Cu(010) along [100] direction, respectively. In the penetration phase, the increment of probe height is calculated by subtracting the probe height before penetration using the current height. For the first scratching pass, the magnitude of probe velocity first increases linearly accompanied by the probe approaching to the sample surface until the initial contact occurs, at which the increase of probe velocity reverses. However, the probe height continues to decrease due to the probe penetrating into the sample surface. Fig 4(A) shows that after the probe height reaches its lowest value, the probe first bounces upwards slightly and then fluctuates around a constant value, accompanied with the fluctuation of probe velocity around 0, indicating that the penetration is stable. Fig 4(A) and 4(D) plot variations of the increment of probe height and scratching force with scratching length, respectively. In the scratching phase, the increment of probe height is calculated by subtracting the probe height before scratching using the current height. It is found that the probe height during the first scratching pass mainly keeps constant value and is lower than the value after the completion of penetration phase. Fig 4(D) shows that the scratching force first increases rapidly and then fluctuates around a constant value of 90 nN when scratching is stable. The strong fluctuation phenomena observed in Fig 4(D) can be attributed to dislocation nucleation events.


Experimental and Theoretical Investigation of Crystallographic Orientation Dependence of Nanoscratching of Single Crystalline Copper.

Geng Y, Zhang J, Yan Y, Yu B, Geng L, Sun T - PLoS ONE (2015)

Mechanical response during the load-controlled multi-passes nanoscratching of single crystalline Cu(010).(a) Increment of probe height-time curves and (b) Probe velocity-time curves during the penetration phase. (c) Increment of probe height-scratching length curves and (d) Scratching force-scratching length curves during the scratching phase.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492598&req=5

pone.0131886.g004: Mechanical response during the load-controlled multi-passes nanoscratching of single crystalline Cu(010).(a) Increment of probe height-time curves and (b) Probe velocity-time curves during the penetration phase. (c) Increment of probe height-scratching length curves and (d) Scratching force-scratching length curves during the scratching phase.
Mentions: Fig 4(A) and 4(B) plot the variations of the increment of probe height and velocity with time during the penetration phases of multi-passes nanoscratching of single crystalline Cu(010) along [100] direction, respectively. In the penetration phase, the increment of probe height is calculated by subtracting the probe height before penetration using the current height. For the first scratching pass, the magnitude of probe velocity first increases linearly accompanied by the probe approaching to the sample surface until the initial contact occurs, at which the increase of probe velocity reverses. However, the probe height continues to decrease due to the probe penetrating into the sample surface. Fig 4(A) shows that after the probe height reaches its lowest value, the probe first bounces upwards slightly and then fluctuates around a constant value, accompanied with the fluctuation of probe velocity around 0, indicating that the penetration is stable. Fig 4(A) and 4(D) plot variations of the increment of probe height and scratching force with scratching length, respectively. In the scratching phase, the increment of probe height is calculated by subtracting the probe height before scratching using the current height. It is found that the probe height during the first scratching pass mainly keeps constant value and is lower than the value after the completion of penetration phase. Fig 4(D) shows that the scratching force first increases rapidly and then fluctuates around a constant value of 90 nN when scratching is stable. The strong fluctuation phenomena observed in Fig 4(D) can be attributed to dislocation nucleation events.

Bottom Line: The correlation of microscopic deformation behavior of the material with macroscopically-observed machining results is revealed.Moreover, the influence of crystallographic orientation on the nanoscratching of single crystalline copper is examined.Both experiments and MD simulations demonstrate that the machined surface morphologies in terms of groove depth and surface pile-up exhibit strong crystallographic orientation dependence, because of different geometries of activated slip planes cutting with free surfaces and strain hardening abilities associated with different crystallographic orientations.

View Article: PubMed Central - PubMed

Affiliation: The State Key Laboratory of Robotics and Systems, Robotics Institute, Harbin Institute of Technology, Harbin, Heilongjiang, 150008, P. R. China; Center for Precision Engineering, Harbin Institute of Technology, Harbin, Heilongjiang, 150001, P. R. China.

ABSTRACT
In the present work, we perform experiments and molecular dynamics simulations to elucidate the underlying deformation mechanisms of single crystalline copper under the load-controlled multi-passes nanoscratching using a triangular pyramidal probe. The correlation of microscopic deformation behavior of the material with macroscopically-observed machining results is revealed. Moreover, the influence of crystallographic orientation on the nanoscratching of single crystalline copper is examined. Our simulation results indicate that the plastic deformation of single crystalline Cu under the nanoscratching is exclusively governed by dislocation mechanisms. However, there is no glissile dislocation structure formed due to the probe oscillation under the load-controlled mode. Both experiments and MD simulations demonstrate that the machined surface morphologies in terms of groove depth and surface pile-up exhibit strong crystallographic orientation dependence, because of different geometries of activated slip planes cutting with free surfaces and strain hardening abilities associated with different crystallographic orientations.

No MeSH data available.


Related in: MedlinePlus