ฝัง
- เผยแพร่เมื่อ 11 ก.ค. 2012
- Segment 1 of lecture 3. Solidification sequence of binary alloys with hypoeutectic, hypereutectic and eutectic compositions, and corresponding cooling curves.
Course webpage with notes: dyedavid.com/mse104
Lecturer: Dr David Dye.
Licence: Creative Commons
Department of Materials, Imperial College, London, UK
![ช้างศึกสู้ต่อไป!! พาเปียโน ดูบอลไทยครั้งแรก ตกรอบแบบโคตรเสียดาย!! l [Nickynachat]](http://i.ytimg.com/vi/4WloIH645Lg/mqdefault.jpg)
out of all the videos i've watched on eutectic phase diagrams this one is by far the most detailed, crystal clear explanation. thank you!
A eutectic is a reaction (in a binary, at a single composition and temperature) where a liquid transforms to two solid phases. A eutectoid is a transformation from one solid phase to two different sold phases.
Thanks, this had me confused.
how the phase boundary of alpha or betta are formed?
You just saved my exam, I have never put the effort in posting comments on youtube videos but thought this was worth it. Explained the clearest as possible
Thank you so much teacher, being a mechanical engineer, I am struggling with the metallurgy section in my post graduate research. your lectures are like an aid box for me
yessssssssssssssssssssssss this was perfect, they didn't teach us about near eutectic alloys in lectures, yet they gave tutorial questions about it.
BEST EXPLNATION on youtube about Eutectic Solidification !!
thank you sir !
Best video I’ve seen on this and I’ve been looking for hours! Great content
Honestly, this was the best explanation of working with phase diagrams! Thank you Sir!
Thank You! So much clearer than my teacher!
Thanks for this, you have explained it well and it certainly is a lot easier to understand now look forward to watching the rest of your videos.
This is the most helpful video on the topic, thanks so much for posting/explaining.
Amazing video! Very well and clearly explained!
This was a great video. It was very clearly explained, thank you!
Thank you for this clear lecture and detailed explanation!
Thank you very much. You explained these concepts very clearly...!!
You sir have gained massive respect. SALUTE!
.this guy knows his stuf ....
u are excellent buddy keep loading more vidz
Thank you professor. You saved my semester
Thank you professor for this excellent lecture. I learned in about 1.5 hours what my professor cannot teach or explain to me.
I will totally look forward to watching more of your videos. 🤣
great video, very clear and concise
A wonderful review! Thank you.
Charles A Berg
Explained really well
thank u for the excellent explaining, u helped me alot
very very good Video, clear and precise
Thanks this has really helped,
So much better than my lecturer at sheffield!
Clear explanation !
Absolute legend!!!
Very good explanation.
Amazing!
thanks boss, very good explanation
Great talk!
great video!
Thank you so much!
thank you !!! you help me a lot ! :)
Thanks for the clip David. Please could you give me the differences between the terms eutectic and eutectoid, I've been looking for some time but can only find the difference of the eutectoids producing two new solid phases from a single phase... Many thanks, Jamie
thank you!
wonderful ....thanks
Thank you so much
THANK YOU
thank you
very helpful!
It is very informative
This is great
Thanks a lot!
For the Lead-Tin eutectic system alloy what is so special about 61.9wt% of tin which leads to lowest melting point and eutectic reaction? What happens to the microstructural level of alloy which causes the melting point of pure components to reduce with addition of other component?
Thank you.
excellent thank you
thank you for this vidio
thank you very much
Thank u so so much
Do you have a discussion regarding the solute distribution?
Interesting ❤️
think you so much
thank you...plz any one explain how to differ hypo & hyper eutectic.
Hi Proff,
With my understating if C(alpha) = concentration of A by % and C(beta) = concentration of B by % which adds to 100%.
At the Eutectic point, as the the concentration C(alpha) and C(beta) doesn't sums up-to 100% as they move extremes. Can you please explain on this.
A really detailed and clear presentation, thank you for that one, I really like your style of presentation! Just one comment on the calculation, i.e. the amounts shown from minute 27 on: I think it would be even clearer, if your numbers fit the actual example. If I see it correctly, the fraction of primary alpha (V_alpha,P) should be much bigger (~70%), whereas the fraction of eutectic should be about 30%?
Thanks for the great video. i am actually sitting exams for this, but do not understand. Thanks for the explaination
thanks heaps
Hypo - below the eutectic point. Hyper - above. See, e.g. wiktionary under "hypo." In some ways, its a silly phrase because it depends which way you plot the phase diagram, which is customary really.
thanks u man
mention the condition that must be provide to obtain full solubility between two metals(who know the soli.)
As the liquid cools you state that the grains are become more and more enriched with beta atoms but then as the solidus line we only have alpha grains. What has happened with the beta atoms??
We have phases alpha and beta - particular crystallographic arrangements. The phases are populated with atoms A and B. So, for a hypo eutectic alloy, then on initial cooling the first solid alpha phase to form is quite pure. As it grows, it rejects B atoms into the liquid, so the liquid becomes enriched in B. This means the liquid is now stable to a lower temperature. Then, we cool some more. Now, the equilibrium solubility of B in the alpha has increased, so the composition of B in alpha increases. This means its fraction can also increase (lever rule). But, its still rejecting B atoms into the liquid, which therefore continues to get richer... and so on.
David Dye Many thanks. I have a question that baffles me a bit. It states: Calculate the amount of eutectic at the end of solidification in an Al-51%wtZn alloy. It gives a hint that maximum solubility in solid is 82.2% and that I should use the scheil equation.Firstly I am familiar with the eutectic point but not with the 'amount of eutectic'. What do they mean? And would it be possible to assist with working out this problem. The phase diagram is a little more complex than the normal FeC one. Possible to do a webinar on this question?
thaaaaaank you!!!
you are a god !!!!
is single phase alloy contains only one metal, i mean if we do controlled cooling and got the single phase alloy then why alloying is done in the first place. Does single phase alloy also contain some amount of other phase metal too??
It depends what you want to achieve. You might add Cr to a solid solution alloy to help develop a protective chromia film during high temperature oxidation. Cu in Monel-400 (a Ni alloy) is there for saltwaer corrosion resistance. Or you might alloy with interstitial O for solid solution strengthening (e.g. in Grade 4 CP Ti). Or you might want to lower the freezing point to make a braze or solder. There are lots of possibilities.
You r perfect 😍
What is eutectic? Show that the eutectic point is invariant?
David, I think there is a mistake in your lever rule at 26.50. I don't think you can directly calculate the vol fraction of alpha in the eutectic for an off-eutectic case directly. What you have written is true for a eutectic composition case only. For an off-eutectic case, you need to first calculate the total alpha and subtract the primary alpha from it to find out the amount of alpha in the eutectic.
I don't think you are correct, sorry.
How many job opportunities for metallurgist are in your area? Seems like steel production and consumption declines everywere.
Generally, in all industries and in most countries, its hard to hire decent metallurgists.
Materials Science is an R&D field, so maybe 50% of the people working in the field have PhDs. I.e. in a steel rolling mill, there will only be a couple of metallurgists (at most) - the production side is mostly done by mechanical engineers. But: there are so few metallurgists, like mining engineers, that there is enormous demand for those that there are.
Also remember that the R&D money is where the problems and profitability are - so the tonnage of Ti isn't very big but it supports quite a thriving community of metallurgists, for example.
Material Science lectures at Birmingham could learn a thing or two from you!
sehr gut from germany
thanks very much sir...my lecture cant explain that clearly.
how do you spell intermixed lamelli?
intermixed lamellae. Lamella is the singular, its latin. :-(
Good news I've found this video;
Bad news only 12 hours left before the exam
👍🏻
Fantastic video and explanation!! However I keep getting distracted by the mouth breathing!! I know people do it subconsciously but I can't get past it. Great content though.
great video. your camera person needs to sit still and keep the board in complete view.
Thank you so much! you make my textbook look like a pile of rubbish
thanks a lot
didnt expect that voice
كنت فين يا فيديو لما كلنا كنا بناخدوا "المتحان طبعا"
That drawing looks like pickachu
very well explained ... thankyou