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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

Load-controlled multi-passes nanoscratching.(a) schematic illustration of nanoscratching experiment configuration; (b) SEM image of triangular pyramid-shaped diamond probe; (c) MD model of nanoscratching.
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pone.0131886.g001: Load-controlled multi-passes nanoscratching.(a) schematic illustration of nanoscratching experiment configuration; (b) SEM image of triangular pyramid-shaped diamond probe; (c) MD model of nanoscratching.

Mentions: The probe-based nanoscratching experiments are carried out in a commercial AFM-based nanomachining system (Dimension Icon, Bruker Company, Germany). Particularly, the equipped Nanoman module in the AFM system is employed for the multi-passes scratching. Fig 1(A) illustrates the configuration of multi-passes nanoscratching experiment. Each scratching pass can be divided into three sequential phases, as first penetration, following scratching and final retraction, respectively. In the first phase of penetration, a pre-determined normal load FN is applied to the cantilever with a normal spring constant (KN) of 275 N/m, which results in a diamond probe (PDNISP, Bruker Company, Germany) penetrating into the sample surface under the contact mode of the AFM. The triangular pyramidal diamond probe shown in Fig 1(B) has a radius of approximately 110 nm evaluated by the blind reconstruction method [26]. In the second phase of scratching the applied normal load (FN) is maintained, and the probe driven by the piezoelectric ceramic transducer scratches 20 μm with a constant velocity of 3 μm/s along the direction highlighted by the red arrow shown in Fig 1(A), which leads to a straight groove of nanometer dimensions formed on the sample surface. To minimize the error of applied normal load between pre-determined and actual values, the scratching direction perpendicular to the cantilever is particularly chosen. In the third phase of retraction, the probe returns to its initial position prior to the first penetration with a constant velocity of 10 μm/s under the tapping mode of the AFM. In the present work, the number of scratching passes is fixed as 3 for each normal load. After completion of the multi-passes scratching, the machined sample surface is first ultrasonically washed in alcohol solution for 10 min to remove chips formed in the scratching process, and then subjected to imaging in the AFM under the tapping mode using a silicon nitride probe with a probe radius of 10 nm.


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)

Load-controlled multi-passes nanoscratching.(a) schematic illustration of nanoscratching experiment configuration; (b) SEM image of triangular pyramid-shaped diamond probe; (c) MD model of nanoscratching.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0131886.g001: Load-controlled multi-passes nanoscratching.(a) schematic illustration of nanoscratching experiment configuration; (b) SEM image of triangular pyramid-shaped diamond probe; (c) MD model of nanoscratching.
Mentions: The probe-based nanoscratching experiments are carried out in a commercial AFM-based nanomachining system (Dimension Icon, Bruker Company, Germany). Particularly, the equipped Nanoman module in the AFM system is employed for the multi-passes scratching. Fig 1(A) illustrates the configuration of multi-passes nanoscratching experiment. Each scratching pass can be divided into three sequential phases, as first penetration, following scratching and final retraction, respectively. In the first phase of penetration, a pre-determined normal load FN is applied to the cantilever with a normal spring constant (KN) of 275 N/m, which results in a diamond probe (PDNISP, Bruker Company, Germany) penetrating into the sample surface under the contact mode of the AFM. The triangular pyramidal diamond probe shown in Fig 1(B) has a radius of approximately 110 nm evaluated by the blind reconstruction method [26]. In the second phase of scratching the applied normal load (FN) is maintained, and the probe driven by the piezoelectric ceramic transducer scratches 20 μm with a constant velocity of 3 μm/s along the direction highlighted by the red arrow shown in Fig 1(A), which leads to a straight groove of nanometer dimensions formed on the sample surface. To minimize the error of applied normal load between pre-determined and actual values, the scratching direction perpendicular to the cantilever is particularly chosen. In the third phase of retraction, the probe returns to its initial position prior to the first penetration with a constant velocity of 10 μm/s under the tapping mode of the AFM. In the present work, the number of scratching passes is fixed as 3 for each normal load. After completion of the multi-passes scratching, the machined sample surface is first ultrasonically washed in alcohol solution for 10 min to remove chips formed in the scratching process, and then subjected to imaging in the AFM under the tapping mode using a silicon nitride probe with a probe radius of 10 nm.

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