Toughening of Glass: Ion-Exchange

[@Miowine]

Excellent Sir thanks it's Irera from iganga, Uganda

[@kartikrathod8606]

Sir.. Ù r too good. Ur videos are so helpul.. To students...

[@maheswarpalagiri566]

The way u teach is awesome. Hope to see different kind of videos (subject) in this channel

[@materialsnerd3303]

kzbin.info/www/bejne/rJPLeKClYtxsfsU

[@katsuragrey]

Thank you for everything

[@praveenr3767]

Sir, when the smaller size vacant site is occupied by larger atom(atom size>vacancy size) , it'll produce tensile stress fields around the neighbour atoms right? If so, how comes the development of compressive stress on the surface?

[@introductiontomaterialsscience]

Thanks for your question. It forced me to think more carefully.The stress field around a hole with a misfitting inclusion is a bit more complicated and interesting than described in the video. Consider a spherical hole. And consider a volume element of material just outside this hole. To increase the size of the hole to fit in a larger sphere you have to push the surface of the hole outwards. This will put the volume element just outside the hole in compressive stress. This compressive stress is in the radial direction. But do not be disheartened. You are not totally incorrect. Imagine a small rod of material lying in the tangential direction of the hole. Since the circumference of the hole is increasing, this rod has to increase in length. Thus in the tangential direction the stress in indeed tensile.The elasticity theory shows that this stress is half in magnitude to the compressive stress on tangential planes. Thus you have both tensile and compressive stress around a hole: compressive in the radial direction and tensile (of half the magnitude of the compressive stress) in the tangential direction. Now consider a crack face. The normal to the crack face may be the radial direction for one hole (with a misfitting large atom) but as tangential direction for another hole. So it will be subjected to both compressive and tensile stress. But as tensile stress is half in magnitude of the compressive stress, net stress will still be compressive.

[@praveenr3767]

@@introductiontomaterialsscience I can't imagine exactly bt I understood what you said. Thank you sir.

[@vinayyadav8638]

Sir, a video for material properties - optical, magnetic, semiconductor properties please

[@vinayyadav8638]

corrosion, prevention and oxidation

[@adarshamaji2307]

Why dont you upload solved paper of material science in Gate???

[@raheelakhtar7243]

Sir I am from Firozabad and I am a manufacturer of glass products mainly vases and all. I just want to kno if this method can be used for the toughening of glass products. Eagerly waiting for your response. Thanks

[@rajeshprasad101]

Ion-exchange method is indeed an industrial process and used for toughening of glass.

[@materialsnerd3303]

kzbin.info/www/bejne/rJPLeKClYtxsfsU im a glass expert.. we can discuss

[@anashnefat1369]

a metal with higher valency will dissolve more easily into a host metal than it would if it had a lower valency. For example, Fe3+ as impurity atoms and Na+ as host will work better than vice versa.???? why why

[@introductiontomaterialsscience]

This question is interesting but I do not know the answer to this question.

[@ahmetbalcoglu3503]

I have questions about physical metallurgy. Can you give me an e-mail that I can reach you?