Research‎ > ‎

2. Nanolayers

Highlights: (1) Cu/Co, (2) Cu/Fe, (3) Mg/Nb, (4) Cu/Ni, (5) Ag/Al
(1). Epitaxial (1 0 0) (1 1 1) Cu/Co multilayers



(2). Cu/Fe multilayers



(3). Mg/Nb multilayers

(4). Epitaxial (1 0 0) (1 1 1) Cu/Ni multilayers
(5). (111) Ag/Al multilayers

Stacking fault and partial dislocation dominated strengthening mechanisms in highly textured Cu/Co multilayers

Y. Liu, Y. Chen, K.Y. Yu, H. Wang, J. Chen and X. Zhang; International Journal of Plasticity 2013 


Highlights:
  • We observe high density inclined stacking faults in (1 0 0) textured FCC Co, and high density twins in (1 1 1) textured FCC Co.
  • We discover large difference in size dependent strengthening in (1 0 0) and (1 1 1) textured Cu/Co multilayers.
  • The impact of partial dislocations on deformation mechanisms of multilayers is discussed.


Microstructure and strengthening mechanisms in Cu/Fe multilayers

Y. Chen, Y. Liu, C. Sun, K.Y. Yu, M. Song, H. Wang, X. Zhang, Acta Materialia 60 (2012), 6312–6321


Highlights:
  • Nanoscale columnar grains in Fe, with an average grain size of 11–23 nm, played a dominant role in the strengthening mechanism when h >= 50 nm. 
  • Abundant twins were observed in Cu/Fe films with (1 1 1) texture when h = 0.75 nm, which led to the retention of high hardness in the multilayers 





High strength Mg/Nb nanolayer composites

B. Ham, X. Zhang / Materials Science and Engineering A 528 (2011) 2028–2033


Highlights:
  • High strength Mg/Nb nanocomposites
  • Metastable bcc Mg
  • Strengthening mechanisms in nanolayers








Mechanical properties of highly textured Cu/Ni multilayers

Y. Liu, D. Bufford, H. Wang, C. Sun, X. Zhang; Acta Materialia 59 (2011) 1924–1933

Highlights:
  • The mechanical behavior of the 
    highly (1 1 1) and (1 0 0) textured Cu/Ni multilayers 
    compares very well with MD simulations.
  • HRTEM studies 
    show the coexistence of high density nanotwins and 
    coherent layer interfaces in highly (1 1 1) textured Cu/Ni 
    multilayers at smaller h. 
  • N
    anotwins significantly 
    enhance the mechanical strength and delay the onset of 
    softening.



Nanotwins and stacking faults in high-strength epitaxial Ag/Al multilayer films

D. Bufford, Z. Bi, Q.X. Jia, H. Wang, and X. Zhang Applied Physics Letters, 101 (2012) 223112.


Highlight: 

Twins induced in Al layers of multilayer Ag/Al films, depite the high twin boundary energy of Al
Twins eliminate the softening that is often observed at small layer thickness in in multilayer films