Composites Research

The Korean Society for Composite Materials (한국복합재료학회)
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Nanoindentation behaviours of silver film/copper substrate

Ag 필름/ Cu기판의 나노인덴테이션 거동 해석

  • 트란딘롱 (국립공주대학교 공과대학 기계자동차공학부) ;
  • 김엄기 (국립공주대학교 공과대학 기계자동차공학부) ;
  • 전성식 (국립공주대학교 공과대학 기계자동차공학부)
  • Published : 2009.06.30
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Abstract

Nanoindentation behaviours on the films of softer Ag film/harder Cu substrate structure were studied by the molecular dynamics method. As a result, it was shown that the stiffness and hardness of films were strongly dependent on the thickness of films. The stiffness and hardness increased with the thickness of film within a critical range as an inverse Hall-Petch relation. The stiffness and hardness of Cu substrate with Ag film less than 5 nm were observed to be lower than those of bulk silver. In particular, the flower-like dislocation loop was created on the interface by the interaction between dislocation pile-up and misfit dislocation during the indentation of Ag film/Cu substrate with film thickness less than 4 nm, which seemed to be associated with the drop of load in the indentation load versus displacement curve.

본 논문에서는 분자동력학 방법을 이용하여 Ag 필름/Cu기판에 대한 나노인덴테이션 특성을 파악하였다. 필름의 강성과 경도는 필름의 두께에 관계되어있으며, 임계범위 내에서, 그래인 크기가 증기하면 강성과 경도도 증가하는 것을 확인하였다. 5nm 두께 이하의 Ag필름/Cu기판의 강성과 경도는 벌크 Ag의 경우에 비해 낮은 값을 나타내었다. 특히 4nm 두께 이하의 Ag필름/Cu기판의 인덴테이션에 있어서, 전위 집적과 불일치 전위사이의 상호작용에 의해 계면상에서 꽃모양의 전위 루프가 발생 하였다. 이는 인덴테이션 하중과 변위 커브에서 하중이 저하되는 것과 관계있는 것으로 사료되고 있다.

Keywords

References

  1. Sommer J, Muschik T, C.H.R. Hεrzig and W. Gust, "Silver tracer diftÌlsion in oriented Ag/Cu interphaseboundaries and corrεlation to the boundary structure,"Acta Matεr.， Vol. 44, 1996, pp. 327-334 https://doi.org/10.1016/1359-6454(95)00166-2
  2. Wolf U., Foiles S.M., and Fishmeitεr H.F., "Study ofmisflt dislocation at the intεrface of weakly bondedmεtal/metal systems," Acta Mater., Vol. 39, 1991, pp.373-382 https://doi.org/10.1016/0956-7151(91)90316-S
  3. Zhou X.W., Johnson R.A., and Wadley H.N.G.,“Misflt-energy-incrεasing dislocation in vapour depositedCoFe/NiFe multilayers, "Phys. Rev. B, Vol. 69, 2004,144113 https://doi.org/10.1103/PhysRevB.69.144113
  4. Labat S., Bocquεt F., Gillεs B., and Thomas 0., "Stressand interfacial structure in Au-Ni and Ag-Cumultilayers," Scripta Mater., Vol. 50, 2004, pp. 717-721 https://doi.org/10.1016/j.scriptamat.2003.11.049
  5. Li Q., " Effect of dislocation source length on yield strength of nanostructured metallic multilayer thin fiIms ，"Mater. Sci. Eng. A, Vol. 493, 2008, pp. 288-291 https://doi.org/10.1016/j.msea.2007.07.098
  6. Noreyan A., Amar J.G., and Marinescu 1., " Moleculardynamics simulations of nanoindεntation of -SiC withdiamond indenter, "Mater. Sci. Eng. B, Vol. 117, 2005,pp. 235-240 https://doi.org/10.1016/j.mseb.2004.11.016
  7. Fang T.H., Wu J.H., " Molecular dynamics simulations onnanoindentation mechanisms of multilayered fllms."Comput. Mater. Sci., Vol. 43, 2008, pp. 785-790 https://doi.org/10.1016/j.commatsci.2008.01.066
  8. Oaw M.S., Baskes M.I., " Embedded-atom mεthod:Oerivation and application to impurities, surfaces, andother defects in metals," Phys. Rev. B, Vol. 29, 1984,pp. 6443-6453 https://doi.org/10.1103/PhysRevB.29.6443
  9. Wadley H.N‘'G .. , Zhou X.W‘', Johnson R.A., and NeurockM., " Mechanisms, models and methods of vapour dεposition，"Prog. Mater. Sci., Vol. 46, 2001 , pp. 329-377 https://doi.org/10.1016/S0079-6425(00)00009-8
  10. Johnson R.A., " Alloy models with theembedded atommethod," Phys. Rev. B, Vo1.39, 1989, pp. 12554-12559 https://doi.org/10.1103/PhysRevB.39.12554
  11. Plimpton S.J., and Hendrickson B.A., “" Parallel moleculardynamics with thε embεddεd atom method," editεd byMattson T. G., published by the American ChemicalSociety, Symposium Sεries 592, 1995, pp. 114-132
  12. Ke1chner C., Plimpton S.J., and Hamilton J.C." Oislocation nucleation and defect structure duringsurface indentation," Phys. Rev. B, Vol. 58, 1998, pp.11085-11088 https://doi.org/10.1103/PhysRevB.58.11085
  13. Lee Y.M., Park J.Y., Kim S.Y., Jun S.,and 1m S.," Atomistic simulations of incipient plasticity underAl(111) nanoindentation," Mech. Mater., Vol. 37, 2005. pp. 1035-1048 https://doi.org/10.1016/j.mechmat.2005.01.004
  14. Misra A., Hirth J.P., and Kung H., " Single-dislocation-based strengthening mechanisms in nanoscale metallicmultilayers," Philos. Mag. A, Vol. 82, 2002, pp. 2935-2951 https://doi.org/10.1080/01418610208239626
  15. Swygenhovεn H.V., Spaczer M., Caro A., and Farkas D.," Completing plastic dεformation mechanisms in nanophasemetal," Phys. Rev. B, Vol. 60, 1999, pp. 22-25 https://doi.org/10.1103/PhysRevB.60.22
  16. Swygεnhoven H.V. , Derlet P.M., and Ilasnaoui A.,“Atomist mechanism for dislocation cmission from nanosizedgrain boundaries, Phys. Rεv. B, Vol. 66, 2002, 024101 https://doi.org/10.1103/PhysRevB.66.024101
  17. Chokshi Il., Rosen A., Karch J., and Gleiter H., " On thcvalidity of thc Hall-Petch rεlationship in nanocrystallinematerials," Scripta Metal., Vol. 23, 1989, pp.1679-1683 https://doi.org/10.1016/0036-9748(89)90342-6
  18. Doemer M.F, and Nix W.D., "A method for interpretingthe data from depth-sensing indentation instruments," J.Mater. Res. Vol. 1, 1986, pp. 601-609 https://doi.org/10.1557/JMR.1986.0601
  19. Hull A., and Bacon D.J., lntroduction to Dislocations,Butterworth-Heinemann, 4th εd. ， 2001