Journal of Materials Science

, Volume 52, Issue 8, pp 4555–4567 | Cite as

Morphology and mechanical properties of nanocrystalline Cu/Ag alloy

Original Paper

Abstract

Hybrid Monte Carlo/molecular dynamics (MD) simulations are conducted to study the microstructures of nanocrystalline (nc) Cu/Ag alloys with various Ag concentrations. When the Ag concentration is below 50 Ag atoms/nm2, an increase in Ag concentration leads to a gradual growth of monolayer grain boundary (GB) complexions into nanolayer complexions. Above the concentration of 50 Ag atoms/nm2, wetting layers with a bulk crystalline phase are observed. The effects of Ag on mechanical properties and deformation mechanisms of nc Cu/Ag alloys are investigated in MD simulations of uniaxial tension. GB sliding resistance is found to first increase and then decrease with an increase in Ag concentration. Surprisingly, we also find that the dislocation density decreases monotonically with an increase in Ag concentration, which suggests that the grain interiors are softened by the introduction of Ag dopants at GBs. In addition, there is a critical Ag concentration that maximizes flow stress of nc Cu/Ag alloys. The flow stress, GB sliding resistance, and the intragranular dislocation densities become less sensitive to Ag dopants when the grain diameter increases from 5 to 40 nm.

References

  1. 1.
    Sakai Y, Inoue K, Asano T, Wada H, Maeda H (1991) Development of high-strength, high-conductivity Cu–Ag alloys for high-field pulsed magnet use. Appl Phys Lett 59:2965–2967CrossRefGoogle Scholar
  2. 2.
    Koch CC (2003) Optimization of strength and ductility in nanocrystalline and ultrafine grained metals. Scr Mater 49:657–662CrossRefGoogle Scholar
  3. 3.
    Meyers MA, Mishra A, Benson DJ (2006) Mechanical properties of nanocrystalline materials. Prog Mater Sci 51:427–556CrossRefGoogle Scholar
  4. 4.
    Lu L, Sui ML, Lu K (2000) Superplastic extensibility of nanocrystalline copper at room temperature. Science 287:1463–1466CrossRefGoogle Scholar
  5. 5.
    Schiotz J, Jacobsen KW (2003) A maximum in the strength of nanocrystalline copper. Science 301:1357–1359CrossRefGoogle Scholar
  6. 6.
    Schiotz J, Di Tolla FD, Jacobsen W (1998) Softening of nanocrystalline metals at very small grain sizes. Nature 391:561–563CrossRefGoogle Scholar
  7. 7.
    Li A, Szlufarska I (2015) How grain size controls friction and wear in nanocrystalline metals. Phys Rev B 92:075418-1–075418-8Google Scholar
  8. 8.
    Song JS, Ahn JH, Kim HS, Hong SI (2001) Comparison of microstructure and strength in wire-drawn and rolled Cu-9 Fe-1.2 Ag filamentary microcomposite. J Mater Sci 36:5881–5884. doi:10.1023/A:1012976610114 CrossRefGoogle Scholar
  9. 9.
    Seydei MKP, Suthanthiraraj SA (1993) Structural, thermal and transport studies on Ag1−xCuxI(0.05 ≤ x ≤ 0.25) solid electrolyte. J Mater Sci 28:3519–3522. doi:10.1007/BF01159832 CrossRefGoogle Scholar
  10. 10.
    Kozlova O, Voytovych R, Protsenko P, Eustathopoulos N (2010) Non-reactive versus dissolutive wetting of Ag–Cu alloys on Cu substrates. J Mater Sci 45:2099–2105. doi:10.1007/s10853-009-3924-7 CrossRefGoogle Scholar
  11. 11.
    Bao G, Xu Y, Huang L, Lu X, Zhang L, Fang Y, Meng L, Liu J (2016) Strengthening effect of Ag precipitates in Cu–Ag alloys: a quantitative approach. Mater Res Lett 4:37–42CrossRefGoogle Scholar
  12. 12.
    Vo NQ, Schafer J, Averback RS, Albe K, Ashkenazya Y, Bellon P (2011) Reaching theoretical strengths in nanocrystalline Cu by grain boundary doping. Scr Mater 65:660–663CrossRefGoogle Scholar
  13. 13.
    Chookajorn T, Murdoch HA, Schuh CA (2012) Design of stable nanocrystalline alloys. Science 337:951–954CrossRefGoogle Scholar
  14. 14.
    Tian YZ, Zhang ZF (2009) Microstructures and tensile deformation behavior of Cu–16 wt% Ag binary alloy. Mater Sci Eng A 508:209–213CrossRefGoogle Scholar
  15. 15.
    Shu S, Zhang X, Bellon P, Averback RS (2016) Non-equilibrium grain boundary wetting in Cu–Ag alloys containing W nanoparticles. Mater Res Lett 1:22–26CrossRefGoogle Scholar
  16. 16.
    Kingstedt OT, Eftink BP, Robertson IM, Lambros J (2016) Inelastic strain recovery of a dynamically deformed unidirectional Ag-Cu eutectic alloy. Acta Mater 113:293–300CrossRefGoogle Scholar
  17. 17.
    Eftink BP, Li A, Szlufarska I, Mara NA, Robertson IM (2016) Deformation response of Ag-Cu interfaces investigated by in situ and ex situ TEM straining (in preparation)Google Scholar
  18. 18.
    Eftink BP, Li A, Szlufarska I, Robertson IM (2016) Interface mediated mechanisms of plastic strain recovery in a Ag-Cu alloy. Acta Mater 117:111–121CrossRefGoogle Scholar
  19. 19.
    Plimpton S (1995) Fast parallel algorithms for short-range molecular dynamics. J Comput Phys 117:1–19CrossRefGoogle Scholar
  20. 20.
    Mishin Y, Mehl MJ, Papaconstantopoulos DA, Voter AF, Kress JD (2001) Structural stability and lattice defects in copper: ab initio, tight-binding, and embedded-atom calculations. Phys Rev B 63:224106-1–224106-16CrossRefGoogle Scholar
  21. 21.
    Williams PL, Mishin Y, Hamilton JC (2006) An embedded-atom potential for the Cu–Ag system. Modell Simul Mater Sci Eng 14:817–833CrossRefGoogle Scholar
  22. 22.
    Youssef KM, Scattergood RO, Murty KL, Koch CC (2004) Ultratough nanocrystalline copper with a narrow grain size distribution. Appl Phys Lett 85:925–931CrossRefGoogle Scholar
  23. 23.
    Sadigh B, Erhart P, Stukowski A, Caro A, Martinez E, Zepeda-Ruiz L (2012) Scalable parallel Monte Carlo algorithm for atomistic simulations of precipitation in alloys. Phys Rev B 85:184203-1–184203-11CrossRefGoogle Scholar
  24. 24.
    Stukowski A, Albe K (2010) Extracting dislocations and non-dislocation crystal defects from atomistic simulation data. Modell Simul Mater Sci Eng 18:085001-1–085001-13Google Scholar
  25. 25.
    Honeycutt JD, Andersen HC (1987) Molecular dynamics study of melting and freezing of small Lennard-Jones clusters. J Phys Chem 91:4950–4963CrossRefGoogle Scholar
  26. 26.
    Falk ML, Langer JS (1998) Dynamics of viscoplastic deformation in amorphous solids. Phys Rev E 57:7192–7205CrossRefGoogle Scholar
  27. 27.
    Cantwell PR, Tang M, Dillon SJ, Luo J, Rohrer GS, Harmer MP (2014) Grain boundary complexions. Acta Mater 62:1–48CrossRefGoogle Scholar
  28. 28.
    Zheng SJ, Wang J, Carpenter JS, Mook WM, Dickerson PO, Mara NA, Beyerlein IJ (2014) Plastic instability mechanisms in bimetallic nanolayered composites. Acta Mater 79:282–291CrossRefGoogle Scholar
  29. 29.
    Tian YZ, Zhang ZF (2012) Bulk eutectic Cu-Ag alloys with abundant twin boundaries. Scr Mater 66:65–68CrossRefGoogle Scholar
  30. 30.
    Swygenhoven HV, Derlet PM (2001) Grain-boundary sliding in nanocrystalline fcc metals. Phys Rev B 64:224105-1–224105-9Google Scholar
  31. 31.
    Mo Y, Stone D, Szlufarska I (2011) Strength of ultrananocrystalline diamond controlled by friction of buried interfaces. J Phys D 44:405401-1–405401-10CrossRefGoogle Scholar
  32. 32.
    Kumar KS, Swygenhoven HV, Suresh S (2003) Mechanical behavior of nanocrystalline metals and alloys. Acta Mater 51:5743–5774CrossRefGoogle Scholar
  33. 33.
    Kocks UF (1970) The relation between polycrystal deformation and single crystal deformation. Metall Trans 1:1121–1143Google Scholar
  34. 34.
    Firstov SA, Rogul OA, Shut OA (2009) Transition from microstructures to nanostructures and ultimate hardening. Funct Mater 16:364–373Google Scholar
  35. 35.
    Conrad H, Feuerstein S, Rice L (1967) Effects of grain size on the dislocation density and flow stress of niobium. Mater Sci Eng 2:157–158CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2017

Authors and Affiliations

  1. 1.Materials Science ProgramUniversity of WisconsinMadisonUSA
  2. 2.Department of Materials Science and EngineeringUniversity of WisconsinMadisonUSA

Personalised recommendations