Stacking-fault energy

The stacking-fault energy (SFE) is a materials property on a very small scale. It is noted as γSFE in units of energy per area.

A stacking fault is an interruption of the normal stacking sequence of atomic planes in a close-packed crystal structure. These interruptions carry a certain stacking-fault energy. The width of stacking fault is a consequence of the balance between the repulsive force between two partial dislocations on one hand and the attractive force due to the surface tension of the stacking fault on the other hand. The equilibrium width is thus partially determined by the stacking-fault energy. When the SFE is high the dissociation of a full dislocation into two partials is energetically unfavorable, and the material can deform either by dislocation glide or cross-slip. Lower SFE materials display wider stacking faults and have more difficulties for cross-slip. The SFE modifies the ability of a dislocation in a crystal to glide onto an intersecting slip plane.[1]

Material Brass Stainless Steel Ag (Silver) Au Si (Silicon) Ni (Nickel) Cu (Copper) Mg (Magnesium) Al (Aluminum)
SFE (mJ m−2) <10[2] <10[2] 25[2] 75[2] >42 90 [2][3] 70[4] -78[5] 125 [6] 160-250 [7][2]
  1. ^ A. Kelly and K. M. Knowles, Crystallography and Crystal Defects, John Wiley & Sons, Ltd., Chichester, 2nd ed., 2012, ch. 9, pp. 269–304.
  2. ^ a b c d e f Hertzberg, Richard W.; Vinci, Richard P.; Hertzberg, Jason L. (2013). Deformation and Fracture Mechanics of Engineering Materials. John Wiley & Sons, Inc. p. 80. ISBN 978-0-470-52780-1.
  3. ^ Luc Remy. PhD thesis, Universite de Paris-Sud, Orsay, France, 1975.
  4. ^ Venables, J. A. (1964). The electron microscopy of deformation twinning. Journal of Physics and Chemistry of Solids, 25, 685–690.
  5. ^ Zhao, Y.H., Liao, Y.Y., Zhu, Y.T. (2005). Influence of stacking fault energy on nanostructure under high pressure torsion. Materials Science and Engineering A, 410–411, 188–193.
  6. ^ N.V. Ravi Kumar et al., Grain refinement in AZ91 magnesium alloy during thermomechanical processing, Materials and Engineering A359 (2003), 150–157.
  7. ^ Lawrence E. Murr. Interfacial Phenomena in Metals and Alloys. Addison-Wesley Pub. Co., 1975.