basic concept of dislocation
TRANSCRIPT
![Page 1: basic concept of dislocation](https://reader036.vdocuments.mx/reader036/viewer/2022062900/58eb9c361a28abeb428b4683/html5/thumbnails/1.jpg)
DISLOCATIONMONIKA.M
115011305009
![Page 2: basic concept of dislocation](https://reader036.vdocuments.mx/reader036/viewer/2022062900/58eb9c361a28abeb428b4683/html5/thumbnails/2.jpg)
Today's Overview
5 Reference
4 Charactrestics
3 Type of dislocation
2 Cause of dislocation
1 Introduction
![Page 3: basic concept of dislocation](https://reader036.vdocuments.mx/reader036/viewer/2022062900/58eb9c361a28abeb428b4683/html5/thumbnails/3.jpg)
One step to the next
Dislocations are happened because of stress applied.
1There can be millions of dislocations in each cubic millimeter of a metal
2The presence of dislocations strongly influences many of the properties of materials
3
![Page 4: basic concept of dislocation](https://reader036.vdocuments.mx/reader036/viewer/2022062900/58eb9c361a28abeb428b4683/html5/thumbnails/4.jpg)
TEM image of dislocated crystal
![Page 5: basic concept of dislocation](https://reader036.vdocuments.mx/reader036/viewer/2022062900/58eb9c361a28abeb428b4683/html5/thumbnails/5.jpg)
CAUSES OF DISLOCATION
They cause “PLASTIC DEFORMATION”. i,e..nothing but the material returns to its original shape and size after the applied stress (load) is released.
1
The ability of a metal to undergo plastic deformation is one of the important property which is utilized for shaping of metals by various fabrication process such as rolling, forging, drawing, extrusion etc.,
2
![Page 6: basic concept of dislocation](https://reader036.vdocuments.mx/reader036/viewer/2022062900/58eb9c361a28abeb428b4683/html5/thumbnails/6.jpg)
SLIP FORMATION
Slip involves sliding of one plane of atoms over the other.
1
Slip is a permanent displacement of one part of crystal relative to the other part.
2
![Page 7: basic concept of dislocation](https://reader036.vdocuments.mx/reader036/viewer/2022062900/58eb9c361a28abeb428b4683/html5/thumbnails/7.jpg)
TWINNING FORMATION
Twinning is a process in which the atoms in a part of the crystal subjected to stress rearrange themselves
1
The plane across which the two part are mirror images is called twinning plane or composition plane.
2
![Page 8: basic concept of dislocation](https://reader036.vdocuments.mx/reader036/viewer/2022062900/58eb9c361a28abeb428b4683/html5/thumbnails/8.jpg)
PARTIAL DISLOCATION
MIXED DISLOCATION
EDGE DISLOCATION
SCREW DISLOCATION
DISLOCATIONS ARE CLASSIFIED INTO FOUR
Where mixed and partial dislocations are not so important as screw and edge dislocation.
![Page 9: basic concept of dislocation](https://reader036.vdocuments.mx/reader036/viewer/2022062900/58eb9c361a28abeb428b4683/html5/thumbnails/9.jpg)
CHARACTRESTICS
1When a metal is plastically deformed,most of energy is dissipated as heat but app 0.5% is stored internally.
2 Distortions of lattice around dislocation line causes lattice strains.
3 In screw dislocations-shear strains.This strain field can affect other dislocations.
4Same sign on same plane repulse each other whereas opposite signs attract and annihilate on meeting.
![Page 10: basic concept of dislocation](https://reader036.vdocuments.mx/reader036/viewer/2022062900/58eb9c361a28abeb428b4683/html5/thumbnails/10.jpg)
Thank you
Monika.M
+001 521 123456
@twitterid
#, Building, Street NameCity, State, Pin Code