I found this very informative, very clear and well explained. Thank you so much for posting this.
@siddharthjena21892 жыл бұрын
Sir What is the Activation energy required for Pipe diffusion in comparison other three diffusions?
@rajeshprasad1012 жыл бұрын
Well, let me just make an intuitive guess. As pipe has only one-dimensional freedom whereas lattice has zero and surface 2-dimensional activation energy of pipe diffusion should be higher than that of surface diffusion and less than that of lattice diffusion. With respect to the grain boundary, it may be comparable. But these are just my guess, we should check some data.
@akashmodi14033 жыл бұрын
Sir I have a doubt. can we call climb motion of dislocation as diffusion path?
@rajeshprasadlectures2 жыл бұрын
Climb motion is not called diffusion path. The climb motion does involve diffusion but the diffusing species either move away or towards the dislocation. The direction of diffusion in not in the direction of motion of dislocation. However, if diffusing species move along the dislocation core then the dislocation does serve as a path of diffusion. It is called pipe diffusion. But in this case, the dislocation itself is stationary and not climbing. This case is not covered in this video.
@keithtong2804 жыл бұрын
Dear Sir, May i ask that, what is the diffusion between surface and lattice? what is the diffusion between grain boundary and lattice? Thank you. Best regards Keith
@rajeshprasad1014 жыл бұрын
If the diffusion happens through the crystal by interstitial or substitutional mechanism it is called lattice diffusion. In atoms diffuse on the external free surface of the crystal it is called surface diffusion. If the diffusing atom moves along the grain boundary between two crystals it is called grain boundary diffusion.
@KuldeepSharma-pk6li2 жыл бұрын
@@rajeshprasad101 Sir, Is activation energy required for pipe diffusion is greater than activation energy required for surface and gb??