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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

MD snapshots of instantaneous defect structures after multi-passes nanoscratching.The top row and bottom row show side and bottom views of instantaneous defect structures after the 3rd scratching pass. Crystallographic orientations of (a) and (d) is (010); (b) and (e) is (110); (c) and (f) is (111). Atoms are colored according to their CNA values, and perfect FCC atoms are not shown.
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pone.0131886.g010: MD snapshots of instantaneous defect structures after multi-passes nanoscratching.The top row and bottom row show side and bottom views of instantaneous defect structures after the 3rd scratching pass. Crystallographic orientations of (a) and (d) is (010); (b) and (e) is (110); (c) and (f) is (111). Atoms are colored according to their CNA values, and perfect FCC atoms are not shown.

Mentions: Fig 10 presents MD snapshots of dislocation structures within the three Cu samples after the 3rd scratching pass. It is seen from Fig 10 that for each Cu sample, there are considerable dislocations formed beneath the free surface that is in the vicinity of the probe, and the dislocation density in the rare of the probe is low due to dislocation annihilations at the free surface [30]. Fig 10 demonstrates that dislocation density is larger for the Cu(100) and Cu(110) than the Cu(111). Furthermore, the geometry between dislocation structures and free surface also varies with crystallographic orientation. For either the Cu(010) or Cu(110), dislocation structures are mainly inclined to the free surface, because of the activation of four {111} slip planes below the free surface. For the Cu(111) there are also dislocations inclined to the (111) free surface observed. However, there are considerable dislocations gliding parallel to the (111) free surface, because of the (111) slip plane parallel to the free surface.


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)

MD snapshots of instantaneous defect structures after multi-passes nanoscratching.The top row and bottom row show side and bottom views of instantaneous defect structures after the 3rd scratching pass. Crystallographic orientations of (a) and (d) is (010); (b) and (e) is (110); (c) and (f) is (111). Atoms are colored according to their CNA values, and perfect FCC atoms are not shown.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0131886.g010: MD snapshots of instantaneous defect structures after multi-passes nanoscratching.The top row and bottom row show side and bottom views of instantaneous defect structures after the 3rd scratching pass. Crystallographic orientations of (a) and (d) is (010); (b) and (e) is (110); (c) and (f) is (111). Atoms are colored according to their CNA values, and perfect FCC atoms are not shown.
Mentions: Fig 10 presents MD snapshots of dislocation structures within the three Cu samples after the 3rd scratching pass. It is seen from Fig 10 that for each Cu sample, there are considerable dislocations formed beneath the free surface that is in the vicinity of the probe, and the dislocation density in the rare of the probe is low due to dislocation annihilations at the free surface [30]. Fig 10 demonstrates that dislocation density is larger for the Cu(100) and Cu(110) than the Cu(111). Furthermore, the geometry between dislocation structures and free surface also varies with crystallographic orientation. For either the Cu(010) or Cu(110), dislocation structures are mainly inclined to the free surface, because of the activation of four {111} slip planes below the free surface. For the Cu(111) there are also dislocations inclined to the (111) free surface observed. However, there are considerable dislocations gliding parallel to the (111) free surface, because of the (111) slip plane parallel to the free surface.

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