Edge dislocation
- 1. PRESENTED BY : 1) ALI SAN IMAM PAVEL ( 1613014) 2) MAHAMUD HASAN TUSHER (1613028) 3) MINHAZ UDDIN (1613026) Edge Dislocation
- 2. What is Dislocations A dislocation is a line that separates the slipped and unsliped part in a crystal Dislocation is a crystallographic defect or irregularity within a crystal structure. ations
- 3. Types Edge dislocation A portion of extra half plane of atoms Screw Dislocation Helical atomic displacement around a line extending through the crystal
- 4. Types of Edge Dislocation 1.Positive Edge Dislocation: The extra half plane is above the slip plane of the crystal and this dislocation is called positive edge dislocation and is denoted by Inverse T. 2.Negative Edge dislocation: The extra half plane is below the slip plane of the crystal and it is called negative edge dislocation and is denoted by T
- 7. BURGERS VECTOR : In material science , the magnitude and the direction of the displacement are defined by a vector is called Burgers vector. It is denoted by b . The Burgers vector of a dislocation is an important property of a dislocation because , if the Burgers vector and the orientation line are known, the dislocation is completely described . Burgers vector and burgers circuit
- 8. For a pure edge dislocation the Burgers vector is perpendicular to the dislocation line, while for a pure screw dislocation the Burgers vector is parallel to the dislocation line. Actually, dislocations in real crystals are rarely straight lines and rarely lie in a single plane
- 10. A convenient way of defining the Burgers vector of a dislocation is by means of the Burgers circuit. Starting at a lattice point , imagine a path traced from atom to atom , an equal distance in each direction , always in the direction of one of the vectors of unit cell. If the region enclosed by the path does not contain a dislocation , the burgers circuit will close. However, if the path encloses a dislocation , the burgers circuit will not closed . The closure failure of the burgers circuit is the bergers vector. BERGERS CIRCUIT
- 20. Slip explains the strength of metals is much lower than the value predicted from the metallic bond. Slip provides ductility in metals. To control the mechanical properties of a metal or alloy by interfering with the movement of dislocations. Influence electronic and optical properties of materials. Significance of Edge Dislocation