OMG.....thank you so much for making me finally understand this. I will be recommending this to my friends if they have any problem with eutectic system.
My Chinese, barely any English speaking lecturer explained this whole playlist in one 40 min lecture... AND he's teaching at one of the biggest UK universities, which Im paying way too much for. This is how you teach. FREE. on CZcams.
No, there's a liquidus-solidus curve change at different composition. Example at 50% eutectic composition which affects the eutectic temperature which may drop
because Pb and Sn have different crystal structure. Different crystal structure didn't allow complete solid solution. So, both alpha and beta has solubility limit represent as the solvus line. Isomorphous diagram, like we see from Cu-Sn, is only for components with same crystal structure, so there's complete solid solution.
In fact, there is no confusion regarding the definition of the eutectic. The definition given here is correct. If you have come across an alternative definition please let me know.
One requirement of 100% solubility in a solid state is that the two elements should have the crystal structure. This is not satisfied in this case as Pb is based on FCC lattice whereas Sn is based on BCT lattice. The phase diagram is still possible. The solvus lines will show limited solubility.
It is an isothermal line. Since the line is associated with the eutectic reaction it is called a eutectic horizontal. We could have called it 'eutectic isothermal', but it is not standard.
No. By definition, a solidus line separates a single phase solid region from a two phase solid+liquid region. This is not true for the eutectic horizontal.
Like all 'Why' questions this one is difficult to answer. We just accept the phase diagrams as experimentally determined diagrams. Of course, since they are equilibrium diagrams, they represent the phases or mixtures of phases in thermodynamic equilibrium. So one can say that we have these phases because they result in the minimum free energy of the system. But then the question remains why the particular combination of phases have minimum free energy? Difficult to answer!
Hi sir. What is the difference between alfa and beta alloy. If alfa is of one crystal structure and beta is of different crystal structure how can both alfa and beta exist as a single crystal. what is the actual difference between alfa and beta sir?? Surface defects - Can we say that alfa and beta in lead tin eutectic alloy at low temperature forms a heterogeneous surface defect. assuming alfa is of one crystal structure and beta is of different crystal structure?
Alpha and beta have different crystal structures and different compositions. In sample both can be present but they occupy different volume elements of the sample. They meet at a surface which we call the the apha/beta phase boundary.
@@introductiontomaterialsscience Thank you sir. Since this is a substitutonal solid solution of 100% solubility how can we have different crystal structure. if it is a interstitial solid solution like we can have two different solid structure like alfa + Fe3C in Iron carbon diagram.
you teaching is extremely helpful as you are explaining things slowly and simply
OMG.....thank you so much for making me finally understand this. I will be recommending this to my friends if they have any problem with eutectic system.
My Chinese, barely any English speaking lecturer explained this whole playlist in one 40 min lecture... AND he's teaching at one of the biggest UK universities, which Im paying way too much for. This is how you teach. FREE. on CZcams.
Very helpful video. Thank you for the clear handwriting and the different colors are a nice touch.
Extremely helpful lecture.
Thank you so much!
Thank you from Canada!! Very well explained I appreciate it
I am from Bangladesh.. Glad to learning from you Sir💚
You r magic sir...
Love u ...
Hope I could meet u...
Thanks for explanation
You are amzing sir, I didn't find explanation like this, thank you so much sir.
Thank you so much Sir❤ you made it easy 😊
very nicely explained. thanks
I wish I could make donations to support sir 🙏
Excellent teaching 👏
Thank you sir, nice explanation
Thanks sir for helpful videos
Sir, why liquidus and solidus curve get change?...... We have only alloy of sn and pb so, why two solid occur by solidify?
Fabulous😋✨
Sir, can a reverse graph exist (with x axis being wt% of Pb)? Does the graph strictly have to be in this format?
That is possible. Whether you draw the diagram with wt%Sn or Wt%Pb as your composition axis is your choice.
Sir how can seprate pb from sn by chemical method
Very nice explained
Is there liquidus and solidus curve occur change only by 62% eutectic composition? What happens when we use other %?
No, there's a liquidus-solidus curve change at different composition. Example at 50% eutectic composition which affects the eutectic temperature which may drop
Will there be a eutectic point in an isomorphous system. Just to clarify
No, isomorphous system does not have any invariant reaction.
Sir, please explain us why Pb-Sn alloy shows different phase diagram?Why there occurs a different alpha n beta solids?
because Pb and Sn have different crystal structure. Different crystal structure didn't allow complete solid solution. So, both alpha and beta has solubility limit represent as the solvus line. Isomorphous diagram, like we see from Cu-Sn, is only for components with same crystal structure, so there's complete solid solution.
Sir which engineering chemistry book should I refer as there are lots of books giving their own definition of eutectic system.
In fact, there is no confusion regarding the definition of the eutectic. The definition given here is correct. If you have come across an alternative definition please let me know.
made it look very easy...
thankyou sir really very useful
Thanks Sir ❤✌
Nice hand writing sir
It is type 2 or type 3 diagram l...?
No one in the world they never teach like you
Sir I really need theory of this topic eutectic system...can you help me 🙏🙏
Sir Is 100% soluility possible in Sn + Pb.. is it possible to draw phase diagrams if the components are not 100% soluble
One requirement of 100% solubility in a solid state is that the two elements should have the crystal structure. This is not satisfied in this case as Pb is based on FCC lattice whereas Sn is based on BCT lattice. The phase diagram is still possible. The solvus lines will show limited solubility.
Sir, why the Eutectic horizontal line is not called as isomorphous line? ( as this line even defines at one temperature at 183 C ).
It is an isothermal line. Since the line is associated with the eutectic reaction it is called a eutectic horizontal. We could have called it 'eutectic isothermal', but it is not standard.
Thank you ,sir.
gyanganga
thankyou so much sir
Isn't eutectic horizontal also a solidus line?
No. By definition, a solidus line separates a single phase solid region from a two phase solid+liquid region. This is not true for the eutectic horizontal.
sir why you didn't explain what is solvus line?
Sir bita hai kya?
👍👍👍👍👍👍
sir why eutectic composition has lowest melting point?
Like all 'Why' questions this one is difficult to answer. We just accept the phase diagrams as experimentally determined diagrams. Of course, since they are equilibrium diagrams, they represent the phases or mixtures of phases in thermodynamic equilibrium. So one can say that we have these phases because they result in the minimum free energy of the system. But then the question remains why the particular combination of phases have minimum free energy? Difficult to answer!
@@rajeshprasad101 thank you sir
@@rajeshprasad101 sir aap to shayar bhi ho 😅🙏🙏 dhanya ho gurudev 🙏🙏
13:56
Hi sir. What is the difference between alfa and beta alloy. If alfa is of one crystal structure and beta is of different crystal structure how can both alfa and beta exist as a single crystal. what is the actual difference between alfa and beta sir??
Surface defects - Can we say that alfa and beta in lead tin eutectic alloy at low temperature forms a heterogeneous surface defect. assuming alfa is of one crystal structure and beta is of different crystal structure?
Alpha and beta have different crystal structures and different compositions. In sample both can be present but they occupy different volume elements of the sample. They meet at a surface which we call the the apha/beta phase boundary.
@@introductiontomaterialsscience Thank you sir. Since this is a substitutonal solid solution of 100% solubility how can we have different crystal structure. if it is a interstitial solid solution like we can have two different solid structure like alfa + Fe3C in Iron carbon diagram.
🙏🥺
sir why the horizontal line is at 183 degrees
I can't really answer this question. I will face the same difficulty if one asked why does Pb melts at 327 degree C.