Slip (materials science)

An external force makes parts of the crystal lattice glide along each other, changing the material's geometry.

[2] Slip in face centered cubic (fcc) crystals occurs along the close packed plane.

[4] Slip in hexagonal close packed (hcp) metals is much more limited than in bcc and fcc crystal structures.

Usually, hcp crystal structures allow slip on the densely packed basal {0001} planes along the <1120> directions.

This typically requires a much higher resolved shear stress and can result in the brittle behavior of some hcp polycrystals.

The type of dislocations generated largely depends on the direction of the applied stress, temperature, and other factors.

[11] Slip-bands can be simply viewed as boundary sliding due to dislocation glide that lacks (the complexity of ) PSBs high plastic deformation localisation manifested by tongue- and ribbon-like extrusion.

And, where PSBs normally studied with (effective) Burger’s vector aligned with extrusion plane because PSB extends across the grain and exacerbate during fatigue;[12] monotonic slip-band has a Burger’s vector for propagation and another for plane extrusions both controlled by the conditions at the tip.

In zirconium, for example, this enables the identification of slip activity on a basal, prism, or 1st/2nd order pyramidal plane.

[19] In low-symmetry crystals such as hexagonal zirconium, there could be regions of the predominantly single slip where geometrically necessary dislocations may not necessarily accumulate.

Schematic view of slip mechanism
Unit cell of an fcc material.
Lattice configuration of the close packed slip plane in an fcc material. The arrow represents the Burgers vector in this dislocation glide system.
Unit cell of a bcc material.
Lattice configuration of the slip plane in a bcc material. The arrow represents the Burgers vector in this dislocation glide system.
Slip systems in zirconium alloys . 𝒃 and 𝒏 are the slip direction and plane, respectively, and 𝝎 is the rotation axis calculated in the present work, orthogonal to both the slip plane normal and slip direction. The crystal direction of the rotation axis vectors is labelled on the IPF colour key. [ 5 ]
A slip band formed on a ferrite grain in an aged hardened stainless steel. The slip band at the centre of the image was observed at a certain load, then the load was increased with a burst of dislocations coming out of the slip band tip as a response to the load increment. This burst of dislocations and topographic change ahead of the slip band was observed across different slip bands (see the supplementary information of the paper). image length is 10 um. [ 8 ]