28. Dislocations: Edge and Screw | Burgers vector and dislocation line

Basics of Mechanical Behavior of Materials
This video deals with the
1. Introduction to edge and screw dislocations
2. Dislocation line vector and Burgers vector
3. Extra half-plane
4. Symbols for Edge and Screw dislocations
5. Volterra Construction (Volterra Cut model)

[@juancarlosalvarezhostos7138]

What I do not understand is how to define the sign of \hat{t}?? Is it pointing in or pointing out the screen plane???

[@PempheroSiliyatheMrEngineer]

Well explained Sir..... I got the whole concept.... Thanks

[@euniceikwanga]

😂😊

[@PempheroSiliyatheMrEngineer]

@@euniceikwanga 🦺😊

[@not_a_handle150]

Thanks for such quality content sir, do you conduct any courses on nptel?

[@manshamanzoor6142]

Sir where is lecture 27? Plz make a playlist

[@nirajchawake]

Dear Mansha, I am working on it and I will upload it soon. Thanks!

[@somyasahoo147]

@@nirajchawake sir please upload it

[@semester420cgpa9]

​@@nirajchawake lec 27??? 😢

[@negarrahbar4813]

32:41', in screw dislocation, as also shown in the pictures, the movement of the dislocation line is perpendicular to the dislocation line. Still, in the yellow box, the text says it parallels the dislocation line! Why? Is that a mistake in the text or did I not get it correctly?

[@nirajchawake]

May be a mistake there. Dislocation always moves perpendicular to the dislocation line (or its tangent vector).

[@negarrahbar4813]

Thank you for the clarification. Great educational videos, especially the visualisations.

[@kamalalagarsamy3783]

In the case of edge dislocation, we extra have half plane that creates the dislocation line. In screw dislocation, what does make dislocation line?

[@nirajchawake]

In the case of an edge dislocation, you can visualize a dislocation line using an extra half-plane of atoms. Screw dislocation line is harder to imagine. I recommend looking at more pictures, videos, and simulations to better understand the displacements they (both dislocations) cause in the lattice. A straightforward way to think of a dislocation line is as the boundary between the slipped and unslipped regions. This will help to understand the nature of burgers vector and dislocation line vector.