Sir I am from Nasik passed out from diploma and now I am taking . Admissions are process is going on. But still their is lots of time remaining. Sir I am telling this because we are completely dependent on self study and their is no perfect guide that we are getting. But your video is really helping me a lot to understand concepts.
Sir, why twins and twin boundaries appear in some specific materials ? Why not these appear in all materials ? For instance- I have observed twins in Cu-9Al and Cu-4Al alloys but not in pure Cu. Why ? Even I observed twins in Ti-6Al-4V. Something which I found that Al is playing a role in forming the twins. Isn't it ?
Not an easy question to answer. It is not clear why you do not see twins in your Cu. This is well reported I have myself seen annealing twins in Cu samples. So the conclusion that Al has something to do with twinning is not justified.
Hi sir. Twin boundry is the result of tilt angle of 180°, then why can't we include in Grain boundry. Does large angle boundary in tilt angle has any limitations??
Hi Hari. Twin boundary is indeed a grain boundary. It is a grain boundary with special orientation relationship of grains across the boundary. The two grains across a twin boundary are mirror images of each other. But the same two grains can also be related to each other by a rotation.
@@introductiontomaterialsscience Let me rephrase the question. Are these defects already present within the early formed nucleii? I noticed that you answered one of the questions by suggesting that the pair of twins might have formed already during their nucleation.
Twinning is the process of the creation of new twins in a matrix. Once created, the boundary between the twin and the matrix is called the twin boundary.
A difficult question. One can think of twinning as a plastic deformation mechanism competing with slip mechnaism. In cases where twinning requires lower stress than slip, twinning takes place. But I am aware that this is not a very satisfactory answer.
![Chlöe - Shake (Feat. Jeremih) [Official Visualizer]](http://i.ytimg.com/vi/aDs_1ufpfv8/mqdefault.jpg)
Sir I am from Nasik passed out from diploma and now I am taking . Admissions are process is going on. But still their is lots of time remaining. Sir I am telling this because we are completely dependent on self study and their is no perfect guide that we are getting. But your video is really helping me a lot to understand concepts.
Very nice explanation, thanks
Nice video Sir keep it up
very clear! Thanks!!!
Sir, why twins and twin boundaries appear in some specific materials ? Why not these appear in all materials ? For instance- I have observed twins in Cu-9Al and Cu-4Al alloys but not in pure Cu. Why ? Even I observed twins in Ti-6Al-4V. Something which I found that Al is playing a role in forming the twins. Isn't it ?
Not an easy question to answer. It is not clear why you do not see twins in your Cu. This is well reported I have myself seen annealing twins in Cu samples. So the conclusion that Al has something to do with twinning is not justified.
@@rajeshprasadlectures Thanks for your reply sir. I have sent you detailed question in the mail. Please check.
Hi sir. Twin boundry is the result of tilt angle of 180°, then why can't we include in Grain boundry. Does large angle boundary in tilt angle has any limitations??
Hi Hari. Twin boundary is indeed a grain boundary. It is a grain boundary with special orientation relationship of grains across the boundary. The two grains across a twin boundary are mirror images of each other. But the same two grains can also be related to each other by a rotation.
@@introductiontomaterialsscience Thank you sir. Now I could visualise it.
Can you classify the defects based on whether they are formed during nucleation or during growth?
This is a difficult question. I am not aware of any such classification.
@@introductiontomaterialsscience Let me rephrase the question. Are these defects already present within the early formed nucleii? I noticed that you answered one of the questions by suggesting that the pair of twins might have formed already during their nucleation.
why twin boundary occur as pair???
why are twin boundaries produced from mechanical shear force in BCC and HCP, but in FCC they're produced from annealing heat treatment??
Thanks for asking. This is a difficult question. I have no answer.
Super sir. Pls upload more video like this.👌👌👌👌
Nice
Pls remove text of speech in video, your language is quite understandable, these texts hide the content what you have written fairly.
Please use the cc button in bottom bar of the video.
Sir live long ❤️
Sir is this twinning
Twinning is the process of the creation of new twins in a matrix. Once created, the boundary between the twin and the matrix is called the twin boundary.
@@introductiontomaterialsscience Thank you
Sir, how twin grains are forming and what advantages or disadvantage we will have.
Please, tell where and how we can see twin boundry/grain?
KING
TWIN BOUNDARY PR PHD HI KARWADIA AAPNE TO
LOVE FROM IIT ROORKEE
THANKS AND REGARDS
SEXY CHANTU
Nice lectures Sir
Sir plz start with twinning topic n types... Bcz we hv not got any lecture on crystallography in our college. Plz help sir
What are you studying? At what level do you want twinning to be discussed?
Why twinning happens
A difficult question. One can think of twinning as a plastic deformation mechanism competing with slip mechnaism. In cases where twinning requires lower stress than slip, twinning takes place. But I am aware that this is not a very satisfactory answer.
@@introductiontomaterialsscience twinning happens in pairs usually, I heard. logic behind that might help understand twinning occurrence better..
Why IN MIRROR IMAGE A IS EXTRA
In twinning the mirror plane can be either a plane with atoms or without. In the example discussed the atomic plane A is acting like a mirror plane.