Metals and Alloys, lecture 3, Solidification

[@waqasmuneer7951]

Thank you for the lecture Professor. I have one question. If we apply this exponentialy decaying profile ahead of the solid liquid interface during solidification of fusion zone in welding process then is it right to say that at the weld centre line, this segregation profile will become narrow because the width of this profile is given D/R???

[@nithiyarajm]

Dear Professor, In concentration Vs Distance profile (21:00), Can I have a sharp interface across which fully solid and fully liquid phase as shown in the plot (21:00 MM:SS) ? If solidification happening over the range of temperature, can i assume fully liquid after the interface? How the liquid fraction / Solid fraction along distance ? Could you please help me in undertanding this ? Thanking you

[@bhadeshia123]

For a physical point of view, I don't see any difficulty in haveing a sharp interface. The concentration profile you mention, has distance on the horizontal axis, so the fractions of solid and liquid follow.

[@deepakdmanjila9969]

Great lecture sir. Could you take a lecture on solidification of copper based alloys?

[@9030372464]

How to increase the heat between solid-liquid interface & Which systems form homogeneous nucleation.

[@divvelaaditya7717]

Hi Professor, When Csl reaches Co then there is no more liquid is present if it is cooling under slow equilibrium conditions, this is from tie rule volume fraction of solid is 1 . so , there is no more liquid to undergo solidification. all liq has got converted to solid. so how does then the interface with with velocity?? Thank You

[@bhadeshia123]

+divvela aditya Solidification stops, so all interfaces are at zero velocity.

[@redouaneechaib3022]

thanks a lot for this video course? It's greatly explained. Thanks again!

[@yoyaya007]

thank you sir this helped me for my final exam thank you again

[@CTF291]

Hi Professor, does having steady state at the interface also correspond to a planar solidification front? Through literature it was mentioned that dendrite stability lies within certain limits of growth velocity. When the solidification front growth rate falls out of the upper or lower limit, the constitutional undercooling approaches the difference between liquidus and solidus temperature for a nominal alloy composition of Co. Assuming equilibrium at the interface, the interfacial liquid and solid composition would then approach Co/k and Co respectively. Since this leads to the steady state condition at the interface, I was wondering if steady state also corresponds to planar solidification. Thank you.

[@bhadeshia123]

Tey Cher Fu Dendritic solidification implies that the liquid ahead of the solid is undercooled. So the interface is not stable in that sense. However, steady-state growth, i.e., growth at a constant rate, is still possible if the dendrite tip advances into fresh liquid, leaving any partitioned solute behind.