Lecture

Kinetics of Dislocations

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In course

PHYS-307: Physics of materials

This course discusses materials physics associated with the mechanical and structural properties of solids, primarily focusing on the physics of dislocation defect dynamics and linking diffusion kinetics to the fundamental physics of phase transformations. ...

Description

This lecture covers the kinetics of dislocations, including the Orowan equation, interaction of dislocations with the crystal lattice, kinks, long distance interaction, stress fields, and instabilities in deformation curves. It also discusses the elastic interaction with point defects, the tetrahedral effect, and interactions with precipitates. The instructor explains the movement of dislocations through point defects, instabilities in deformation curves, and interactions with extended defects like precipitates and grain boundaries.

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Instructor

Thomas La Grange

Expertise Electron Microscopy, Aberration Correct Scanning Transmission Electron Microscopy, Electron Diffraction, Ultrafast Transmission Electron Microscopy, Electron Energy Loss Spectroscopy, Energy Dispersive Spectroscopy, Materials Science, High-speed deformation, Dislocation Dynamics, Skyrmionics, Martensitic Phase Transformation Theory, Solidification Expertise Electron Microscopy, Aberration Correct Scanning Transmission Electron Microscopy, Electron Diffraction, Ultrafast Transmission Electron Micro

Official source

Ontological neighbourhood

Chemical engineering

Materials science: Deformation of materials

Related concepts (32)

Dislocation

In materials science, a dislocation or Taylor's dislocation is a linear crystallographic defect or irregularity within a crystal structure that contains an abrupt change in the arrangement of atoms. The movement of dislocations allow atoms to slide over each other at low stress levels and is known as glide or slip. The crystalline order is restored on either side of a glide dislocation but the atoms on one side have moved by one position. The crystalline order is not fully restored with a partial dislocation.

Deformation (physics)

In physics and continuum mechanics, deformation is the transformation of a body from a reference configuration to a current configuration. A configuration is a set containing the positions of all particles of the body. A deformation can occur because of external loads, intrinsic activity (e.g. muscle contraction), body forces (such as gravity or electromagnetic forces), or changes in temperature, moisture content, or chemical reactions, etc. Strain is related to deformation in terms of relative displacement of particles in the body that excludes rigid-body motions.

Deformation (engineering)

In engineering, deformation refers to the change in size or shape of an object. Displacements are the absolute change in position of a point on the object. Deflection is the relative change in external displacements on an object. Strain is the relative internal change in shape of an infinitesimally small cube of material and can be expressed as a non-dimensional change in length or angle of distortion of the cube. Strains are related to the forces acting on the cube, which are known as stress, by a stress-strain curve.

Stress (mechanics)

In continuum mechanics, stress is a physical quantity that describes forces present during deformation. An object being pulled apart, such as a stretched elastic band, is subject to tensile stress and may undergo elongation. An object being pushed together, such as a crumpled sponge, is subject to compressive stress and may undergo shortening. The greater the force and the smaller the cross-sectional area of the body on which it acts, the greater the stress. Stress has units of force per area, such as newtons per square meter (N/m2) or pascal (Pa).

Creep (deformation)

In materials science, creep (sometimes called cold flow) is the tendency of a solid material to undergo slow deformation while subject to persistent mechanical stresses. It can occur as a result of long-term exposure to high levels of stress that are still below the yield strength of the material. Creep is more severe in materials that are subjected to heat for long periods and generally increase as they near their melting point. The rate of deformation is a function of the material's properties, exposure time, exposure temperature and the applied structural load.

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