Time-temperature-transformation (TTT) diagram

[@ajaikrishna3043]

It is mind boggling that, this content is free. This is such an amazing explaination of TTT diagram.

[@minason2823]

I think this video lecture is the ultimate explanation of TTT diagram in my opinion! So detailed, elabroated, and thorough lecture. Thank you so much sir!

[@waqasmuneer7951]

Hats off. Mind blowing professor. Never understood the reason of finer and coarser grains. Also never paid heed to how TTT diagram is created. Amazing.... Thank you.

[@sankalp7135]

Sir, your teaching content is unparallel. This is GOLDEN!

[@IsaiahNBlack]

I came to understand simple cooling paths, and I got so much more! thanks.

[@satyamsingh-js4hh]

So interesting video Sir..... Different colour are attractive..... It's perfect method to teach student.....

[@unpluggedamit3647]

Thats y he teaches in IIT D. Mera bhi sapna tha IIT ..but kya kare NIT mila...ussi me khus hu😥

[@sudhirNITT]

@@unpluggedamit3647 which nit

[@FarTennis]

this really helps me review basic metallurgy for my thesis. thank you, sir. respect.

[@abhijitsinha5316]

Which Iit?

[@tomonasstudyhub2274]

wanted to just watch a video about TTT diagram of steel cuz of end sem tomorrow. So glad that I took the time to watch this one first. The last fact was truly mind boggling. Honestly must have been the first time I cursed out loud while studying not because of frustration, but because of pure awe!!!!

[@itzshadhu673]

16:15 In Fast Cooling temperature range is lower than Slow Cooling And for Fast Cooling due to low temperature range we will get Fine Grains and for Slow Cooling due to High temp range we will get Coarse Grains 20:00 In case of Quenching 22:20 we will get Glass or Amorphous Solid

[@nhatle7859]

I have a question. Why during the crystallization, does the temperature decrease? I think the temperature should be supposed to keep constant.

[@sarathbabu1990]

Your teaching method and your knowledge of the subject are remarkable Professor.

[@ptiwaridotin]

God bless you for this video, professors at Tier 3 universities can not match this even in their dreams.

[@sarafaaani]

tommorow is our end-sem, thanks professor!

[@Hogward9.5]

Thanks for this amazing lecture sir. Very simple explanation with deep understanding.

[@chakhla5614]

If only such teachers existed all around!!❤️

[@jaya622]

Remarkable...crystal clear explanation..Thanks a lot Sir

[@-NSanthosh]

Thank you 🙏 so much sir... No need of going to college.. ,Your videos are more enough to gain knowledge..

[@dipanjanpal2794]

Cleared all the ambiguity regarding T-T-T diagram in the most effective manner. Excellent piece of teaching. Thank you very much sir.

[@lilly-ct6mk]

Wow! thank you sir!!! May God bless you!!

[@SoumilSahu]

What happens if the cooling curve touches the start curve twice and never hits the finish curve?

[@adityarathore7021]

You make metallurgy very interesting, Sir! Thanks a lot.

[@gregg.861]

Best video for Materials Science even seen. Help me get through PhD qualifying exam

[@manojprasad2166]

Very good video, would recommend 1.25 speed for viewing.

[@harshawardhandeore8881]

This is the best explanation of TTT curve.... Thank you very much sir

[@vishnusuresh168]

Being speechless after watching this video.... awzm sir.

[@etes]

Sir, there can be a cooling curve in between nose of green curve and red curve, which cuts the green line but doesn't cut the red line. What would be out come of such curve?

[@chaithanyaagurunathan4542]

You are absolute Gem sir hats off to you

[@samlocr388]

so nice of you to post this

[@sadman097]

Thank you so much sir! best vedio on this topic So much details and easily understandable

[@ishanbasketball1719]

beautifully explained the ttt diagram concept

[@scientium8770]

16:20 You said that "On faster cooling, the temperature range over which the transformation happens is lower than in slower cooling."; but instead the temperature range increases in faster cooling. Like in the cooling lines you have drawn, the slower cooling line has a small temperature range(the vertical height) when compared to faster cooling. I am confused here. Please help!!

[@introductiontomaterialsscience]

What we mean is that at slower cooling the transformation starts at higher temperature.

[@kishorkumarkumawat7007]

Very nice lecture sir. Well explained.

[@madhuriwawre1921]

Awesome sir.. very student friendly teaching methodology... 🙌

[@akashjha9194]

Sir you said that for faster cooling,the temperature range for which transformation occurs is lower. Does this mean that the difference of upper and lower temperature values is lower than that for slow cooling? Because by observing the TTT diagram,it seems the other way around.

[@rajeshprasad101]

It means that the start temperature for faster cooling is lower than that for the slow cooling. similar the end temperature for faster cooling is lower than that for slower cooling.

[@akashjha9194]

@@rajeshprasad101 Thanks sir I got it.

[@niladrichakraborty3795]

Nive understandable Lecture Sir. Thank you sir👏👏

[@pramitril1]

After Coarse Pearlite is formed then I quench it to room temperature what I will get?

[@introductiontomaterialsscience]

It will remain coarse pearlite. Once austenite is transformed, no further transformation is expected.

[@AakashKumar-gl2fk]

Thanks sir for your easy explanations

[@ChenLin-jy2ev]

Thank you very much. This video helps me a lot!

[@johns.khalkho9831]

Sir, will you please explain under what conditions it is called fast cooling and slow cooling? And if we do water quenched aluminum composite what will be the effects on grains, will it developed finer grains?

[@nc-pf3qm]

Lets see it for iron...Water quenching of austenite is fast. So it will give martensite directly(fast cooling). Oil quench will give very fine pearalite,air cooling will give fine pearalite. Nd furnace cooling will give coarse pearalite.

[@parmalchouriya738]

Great video sir and you are also great ☺☺☺☺

[@ankushsaha007]

Sir here at 16:19 the two cooling curve u took was it for water or alloy?because if its liquid water then its pure substance and pure substance solidifies at fixed temperature,if its alloy then how we are able to superimposed an alloy curve to an pure substance's TTT diagram?

[@rajeshprasadlectures]

This example is of a pure liquid. When we say a pure liquid freezes at a fixed temperature, we mean the temperature at which solid and liquid are in thermodynamic equilibrium. Freezing will happen at this temperature only if the cooling rate is extremely slow to allow for equilibrium to be attained. At normal or faster cooling rates undercooling is possible, i.e., the liquid will remain as a metastable liquid even below the equilibrium freezing temperature. This liquid can thus solidify at a temperature below the equilibrium freezing temperature.

[@ankushsaha007]

@@rajeshprasadlectures thanx a lot sir 🙏

[@suryasen9895]

Excited to study what happened in the nxt lecture

[@ashabajpai3921]

If two identical materials are cooled with same cooling rate but one is cooled from say 820 and the other from 790, transformation temp of former being higher ,will it have coarser grains?

[@aiynasharma3347]

Amazing explanation

[@gulamquadir1077]

Dear Sir, thanks for the lovely explanation. I have one question, can any liquid be transformed to Glass by Quenching?

[@introductiontomaterialsscience]

Yes. If you cool a liquid fast enough there is no time for atoms to organise in crystalline structure. Thus it becomes glass.

[@gulamquadir1077]

@@introductiontomaterialsscience thank you Sir

[@etes]

7:15 Why would start of solidification late at lower temperatures?

[@kareemmehdi]

You end up having so many grains that are so small they can’t really come together to form a solid

[@Raj-er8fc]

See previous video bro. At low temp, atomic mobility is less so the nucleation and growth rate is less.so more time required for nucleation and growth

[@abhiseknayak6063]

Sir what will we get on cooling at upper critical cooling rate (the cooling line just touch and pass to the Ts curve) ?

[@hal9000svk]

Thanks for the video. Can anyone help? I would like to find out how to find out what quenching time is needed to achieve bainite transformation (bainite hardening) in chromoly alloy steel 42CrMo4 (SAE 4140). For example when I use oil as quenching medium with constant 350°C and I then I dip chromoly workpiece with austenite temperature into it and I need to know for how long it should stay in the oil and if there is a max time that can not be exceeded.

[@lokeshpadyal9001]

Valuable lecture ....thank you sir

[@nhatle7859]

Sir, I have a question. Why when you supercool the liquid, during the crystallization, does the temperature decrease? I think the temperature should be supposed to keep constant.

[@ravindunethmina7549]

thank you sir for clear explaining.......

[@praveenbhyan1722]

a very good explanation sir

[@adarsh7307]

awsm explanation .....

[@railwayvlogs6829]

Thank you sir. It's outstanding.

[@secretsoul9319]

Indebted to u the GEM💎🙏🙏🙏

[@SakshiSharma-pn4gk]

Sir very very interested video thanku . To

[@이찬희-n7s]

Sir, thank you for your very nice explanation of TTT diagram, but i have a quesiton.. in this video, your diagram looks like CCT diagram, not TTT diagram because of the continuous cooling rate you draw... so.. isn't it a CCT diagram??

[@introductiontomaterialsscience]

You have asked a serious question. And that points to subtle point regarding the difference between TTT and CCT. The diagram I have drawn is a TTT diagram. The CCT diagram does not have the lower part of C curve. So strictly speaking I should not draw a continuous cooling curve on these diagrams. I avoided discussion on CCT diagrams in these videos. So I did not go into these details and loosely drew continuous cooling curve on a TTT diagram, which in a strict sense is incorrect.

[@이찬희-n7s]

@@introductiontomaterialsscience Ah.. now i see! Thank you so much for answering my question!

[@abhiseknayak6063]

Sir why we get coarse grains on low cooling rate and fine grains on higher cooling rate?? What is the cause behind this sir ?

[@IITian_shubham_shekhar_rajput]

Sir we've already seen that for an alloy, transformation occur at a range of temp.(except for eutectic composition)...but in TTT diagram phase transformation start and finished at the same temp...HOW IS THIS POSSIBLE??

[@palani8081]

in heat treatment how liquid phase is coming?

[@rajeshprasadlectures]

In this videoTTT diagram is drawn for solidification and not for heat treatment.

[@prakharbhalla9461]

Sir since at temperature below and above the nose the transformation rate is small so shouldn't it be that the gap between start and finish curve along isotherm should be larger as compared to nose because larger the transformation rate less time it will take to transform

[@monishreddy4466]

Sir, which property of glass distinguishes it from solid and make it more of a liquid

[@rajeshprasadlectures]

The distinction between crystal and glass is their atomic arrangement. In crystals the atoms are periodically arranged. Atomic arrangement in glass is disordered. The atomic arrangement of liquid is also disordered and in this sense, glass is compared to a liquid.

[@mathateja1612]

Below melting point how solid transfers to liquid

[@AnupKumar-wd1ln]

Sir, how the process of slow cooling or fast cooling is done practically?

[@introductiontomaterialsscience]

Think of casting. Sand casting gives relatively slower cooling rate than die casting. And then there are techniques called rapid quenching where one cools so fast that one gets amorphous or glassy phase.

[@LoneWolf-zj8it]

thank you for that last interesting fact ;-)

[@itibalinong1060]

Wow What an explanation

[@CALLOFDUTY2020-g5t]

Was he saying about the transformation of water or any other substances

[@sourabhsuryawanshi9522]

Maza hi aa gya sir .

[@rishi_d_mango]

this is fantastic.

[@Duarte_Lima]

Ganda rei

[@ronaldowijaya1901]

Thanks for making this video

[@prakharkumar8024]

Amazing teacher

[@alokkumarnyati]

Nice lecture 👍

[@adityagarg259]

the present teacher's of APL102(IITD) are very bad when compared to you sir ❤️

[@johnnybhai7529]

Today I have MSE exam.... That's y i am here... 😄

[@anandh1967]

Sir is that glass is called as martensite? And no doubt IIT is always good at teaching

[@jinbaofan8957]

I love you!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[@adarsh7307]

best lecturee

[@sriharanr5493]

Super sir💥💥🤙

[@AakashKumar-gl2fk]

Happy liquid 😂

[@pranjitnath7]

Thanks so much sir

[@chetanbolishetty5980]

amazinggggggg!!!!!!!!!!!!!!!!!!!!!!!!!

[@chittanagadurgaprasad599]

TQ so much sir

[@sanjayyadavazam]

Thanks sir.

[@pranjalgurung9030]

Can you explain it little bit in hindi

[@pranjalgurung9030]

Can anyone help me out

[@ankitdubey9310]

gold

[@ابوعثمان-ع2ه]

نعيما دكتور

[@mohdarshadaleemkhan4606]

Sir please provide notes

[@mohdarshadaleemkhan4606]

Overall course

[@pranjalgurung9030]

Kuch smjh me ni aaya

[@animeshsingh4320]

budhdhe thoda tez padhale