Slip vs Cross Slip
Both a slip and cross slip fall under the field of materials science. Material science is the scientific field that applies to the properties of matter in the areas of science and engineering. This field also deals with the relationship between the material’s structure in a molecular level and their macro-level properties. Since material science deals with matter, there are elements of applied physics and chemistry used in this field. Materials science is part of forensic engineering and failure analysis.
The field often uses common materials such as metal alloys, polymers, ceramics, plastics, glasses, and composite materials.
Every material has its own strength. However, if excessive stress (load) is applied to the material, the structure of the material breaks, and its original form changes. The material is considered a “failure.” A failure of a material can be described as a dislocation which can result in a slip.
“Slip” is defined as “a process where the plastic flow occurs in metals or crystal planes and makes the planes slide past each other.”
A slip happens due to a dislocation along the slip planes. The dislocation can be caused by stress on the material. After sufficient stress is applied, dislocation appears on a particular set of crystallographic planes (also known as slip planes) which contain the dislocation and the direction of the plane’s movement. A slip also takes place in an environment called a slip system which is the combination of a slip plane and a slip direction (or crystallographic direction). A slip system identifies where the moving dislocations are and the direction where they are going.
As the movement of many dislocations on the material, a slip will eventually produce plastic deformation on the substance itself. However, it allows deformation without breaking. Since individual bonds are broken to move the dislocation, the new bonds are formed during the slip process. The resulting deformation from the process is irreversible.
On the other hand, a cross slip is the glide of a screw dislocation that transfers from one slip to another slip plane. The second plane receives shear stress and allows the dislocation to glide into it. It is also the characteristic or description of a crystal after undergoing plastic deformation and thermal recovery.
Cross slips occur when a screw dislocation changes planes. The screw dislocation constricts on the first plane and “bows” into the new slide plane. The constrictions also move along the screw dislocation. As the screw dislocation glides in a perpendicular direction from the applied stress across the new slide plane, it will cut the top and front part or half-way through the second slide plane.
Cross slips occur more frequently at a crystal set in a higher temperature. The cross slip can be observed in TEM or in the surface of the deformed crystal with the help of an electron microscope.
Cross slips often occur in aluminium and in body-centered cubic metals.
The result of both a slip and a cross slip is plastic deformation.
Summary:
1.The field of materials science encompasses both clips and cross slips.
2.It is when an extreme amount of stress is placed on the material causing a dislocation. The movement of the said dislocations is called a slip that will produce plastic deformation.
3.Both a slip and a cross slip are results of applying stress to a particular material.
4.However, a cross slip is more particular since it involves a screw dislocation, a specific type of dislocation.
5.A cross slip particularly occurs in a screw dislocation compared to a slip which can occur in an edge or a mixed dislocation
6.The slip process breaks and forms the material’s bonds as it occurs. The process itself is irreversible once it starts.