I am currently enrolled for mechanical engineering in Australia. It's fascinating that most of the topics from my course are available by you guys!! Really appreciating. :D
@pankajkumarpandey66584 жыл бұрын
Sir, I am AMIE in Mech Engg but today I understood this theory in deep. Thanks a lot. Vidwan sarvatra poojyate
@saidamzil4732 Жыл бұрын
The best Tutor!!! Dr. RAJESH PRASAD
@roshanmarode46792 жыл бұрын
Dear Prof. I really appreciate the way of your teaching. I am Pursuing PhD in Mechanical and major contents are aligned towards my study. Thanks again for the in depth explanation.
@miloszivkovic61183 жыл бұрын
Is there any video or explanation how to apply this in practice? I assume multiple annealing after high plastic deformation, or forging-annealing repeated process? Also what determens how much new grains will start to grow from single grain during recrystalisation? Would be great to add particless for grain boundaries curving , but with opposite charge like foreign single grains to act as repeling force, it would be much harder to slip.
@vikasbite84543 жыл бұрын
Informative...nice lecture
@mistervoldemort75405 жыл бұрын
thanks, simpe and effective
@darshangardia2 жыл бұрын
Hats off to your efforts Sir ☺️
@vayronmaclean873 жыл бұрын
Great video, thanks you so much
@krithikas37215 жыл бұрын
Sir, please take a video about solidification in detail
@Ritikkumar-mq3fm3 жыл бұрын
Sir we want more NPTEL lectures from you. Please make lectures on others topics as well. Please sir.
@shoboyjr3 жыл бұрын
Very good explanation
@alienmoondudes80715 жыл бұрын
very helpful video. I have a question though. How come small grains increase creep rates?
@introductiontomaterialsscience5 жыл бұрын
Small grains will increase creep rate through two mechanisms which do not involve dislocation motions. One is the diffusion of vacancies from boundary oriented perpendicular to stress axis to boundary parallel to stress axis. This is stress assisted diffusion. And the diffusion distance depends upon the grain size. So smaller the grains size, shorter the diffusion distance and so more diffusion and associated creep. The second is grain boundary sliding. Smaller grains provide more boundary area to slide on thus increasing creep by grain boundary sliding
@aravindkumar66313 жыл бұрын
@@introductiontomaterialsscience sir when you talk reasoning about strees assisted diffusion then why single fine crystals have high creep resistance they also will have vacancy assisted diffusion and as the grain size is small I The diffusion should be more according to that logic
@introductiontomaterialsscience3 жыл бұрын
@@aravindkumar6631 Single crystals do not have small grain size. The entire sample is a single grain, so the grain size is as large as the sample itself. There is nothing like single fine crystals.
@ayay98354 жыл бұрын
Sir can u please tell that a) how grain size affect thermal conductivity?? b) how grain size affect fatigue strength ??
@MarcHeijligers Жыл бұрын
I assume the last equation should be L / ( M x ( N - 1 )) ?
@pradgadagkar85573 жыл бұрын
Excellent
@maheshwarareddyjedla69913 жыл бұрын
sir, can you please suggest to me the best method to find the avg grain size of the rolled specimen when I measure along the rolling direction the grain size is more and when I measure along the transverse direction grain size is less. As people say rolling increases the grain sir which one we have to use either rolling direction or transverse direction?
@AbuDujana6927 ай бұрын
Did you get any reply to this query...if you can share your findings, I will be obliged....looking forward
@maheshwarareddyjedla69913 жыл бұрын
sir, I am working on Al-Li 8090 alloy, I found the higher strength on T3 temper which has coarse grain after annealing the grain are fine but with lower strength can you please explain this? 6:08!
@introductiontomaterialsscience3 жыл бұрын
This is interesting! I have no explanation.
@deependrachauhan1741 Жыл бұрын
ur gr8 sir
@mangeram27312 жыл бұрын
Great thanks Sir
@mehtashirley3 жыл бұрын
why do they say grain refinement is way to achive both high strength and ductility
@introductiontomaterialsscience3 жыл бұрын
Both the increase in strength and ductility is observed experimentally. Increase in strength is explained theoretically by the obstruction to the dislocation motion. I am not aware of any simple theoretical explanation for the increase in ductility.
@edhinaaopinion22625 жыл бұрын
Thankyou sir
@subhasishpradhan4524 жыл бұрын
for steels carbon as interstitial inclusion is generally stronger than chromium as substitution solid solution, why?
@subhasishpradhan4524 жыл бұрын
even if the strain field generated by chromium would be higher!
@introductiontomaterialsscience4 жыл бұрын
Usually, strain field induced by interstitial solid solution is much more than that introduced by a substitutional solid solution. This is the reason by the interstitial solid solubility of C in Fe is so limited.Thus a small amount of C causes more hardening than similar or even more amount of Cr.
@AbuDujana6927 ай бұрын
❤❤❤
@kumars9591 Жыл бұрын
Sit please clarify me that here the grain diameter we talking about is Prior Austenite grain Boundary Or ferrite size ?
@introductiontomaterialsscience Жыл бұрын
What is described here is a general phenomenon applicable to all materials. For mild steels, you can take the ferrite size as the grain size.
@kumars9591 Жыл бұрын
@@introductiontomaterialsscience thank you proff.
@sripadarajapaga80513 жыл бұрын
Sir, how can we say that dislocation will be at the slip plane and on what basis we can say that the dislocation will slide on the slip plane?
@introductiontomaterialsscience3 жыл бұрын
The plane defined by the dislocation and its Burgers vector is called its slip plane. Thus the dislocation lies on the slip plane. To male it glide along the slip plane we need to apply a shear stress larger than a critical value called the critical resolved shear stress.
@sripadarajapaga80513 жыл бұрын
@@introductiontomaterialsscience Got it Sir. Thanks for your early response
@Immsnegidec045 жыл бұрын
sir what is the effect of grain size on ductility...plz explain it
@AForAyush255 жыл бұрын
Manish Negi larger the grain size more will be th ductility as the obstacles in dislocation motion is less and it is easy to deform the material plastically
@Immsnegidec045 жыл бұрын
@@AForAyush25 do you have any reference book ? I read quora ans but some of them said reverse of this...So I am in so much confusion about this thing...
@samuelturner56204 жыл бұрын
Strong materials are less ductile. So, if you start reducing grain size you will also reduce ductility.
@srijansrivastava95124 жыл бұрын
The more finer the grains the more ductile material.
@prakharbhalla94613 жыл бұрын
Sir at 12:45 you told that there are N intercepts. But if there are N intersections then there should be N-1 intercepts. Isn't that correct
@introductiontomaterialsscience3 жыл бұрын
Well, at both ends we count only half intercepts thus giving N intercepts for N intersections.
@FitnessfreakHC3 жыл бұрын
yaar simple language me kyu nhi btate sir....sab upper se nikal gya