I really appreciate the way you explain these concepts. Examples like the tearing down of the house vs. just fixing it up is the kinds of examples that stick in your head.
thank you! my professor skimmed over this subject fairly quickly, your explanation was quick and simple and helped me understand the process of recrystallization way better!
Great explanation! I just will add that the cold work percentage will affect the recrystalization temperature. The higher %, the lower recrystallization temp will be.
Hey, professor, thank you for the great lectures, wanted to study material science but never had the chance, so I appreciate the free lessons. I'd like to ask, if I wanted to find all previously experimented Cu-Fe alloys (%wt, conditions...etc)and their properties for example, how would I go about doing that exactly?
Unfortunately, still have problems with materials databases. They are starting to grow and get better, but there is not one that is completely comprehensive. What I would do, is start with a crystal structured database and look for pure single phase compounds there because you can check them easily. However, this will be for single phases only and I imagine you are looking at multi-phase alloys. In that case you will need to search literature directly. There are probably some review articles that you can start with.
In the cold work amount graph, the grain sizes of the "cold worked" structure are larger than the "original structure". Shouldn't the grain size of the "cold worked" structure be smaller than the grain size of the "original structure" due to the increase in dislocation density caused by the increase in grain boundaries?
I’m a dental student and we are studying about the material science to know how prosthetics and orthodontic appliances work! Your video was absolutely brilliant and easy to understand thank you 🙏 I have a question will there be a phase where there is recrystallization with no change in strength and hardness? As in my slides it’s mentioned in the hot-working metals there won’t be change in the hardness unlike the cold-working (increase in hardness and decrease in ductility).
Hi, thank you for your video. I have an additional question. The recrystallization temperature corresponds to full recrystallization after 1 hour. What if a hardened metal is constantly at a middle temperature (half that temperature for example) ? Does it still undergo the recrystallization process?
Can you explain how the stacking fault energy affects the ease of grain refinement in certain materials? For instance, in low SFE materials, such as Cu, apparently grain refinement is more difficult than in higher SFE materials such as Fe. What causes this?
during hot extrusion, the metal recrystallizes as it exits the extrusion die while the material temperature is still > than the recrystallization temperature.. Grain growth can continue post extrusion because the metal is still hot enough for different grain growth depending on the material metals like copper and silver with very high purity will show garin growth after extrusion if the metal remains hot... if the metal is quenched in water as it exits the extrusion die, you can limit grain growth after extrusion
Hi professor, thanks for your explanation of these concepts. Cou;d you please tell me which paper the image "schematic representation of the cold-worked and anneal cycle showing the effect on properties and microstructure" in the video is from?
i may be confused, but i don't think increasing grain size (at least on a monophasic sample) will increase ductility. i think it will actually decrease it.
@@TaylorSparks i don't have any reference ready to give you, but as far as i know, that's why microalloying of steels (with Nb for instance) is so interesting. differently than other hardening mechanisms, decreasing the average grain size doesn't decrease ductility. the thing is that when you have many smaller grains, the propagation of a crack becomes substantially more difficult than on a coarser grains structure
@@Yodavid1decreasing the grain size will make the mechanical properties of ALL metals higher, higher yield strength, UTS & LOWER elongation. you have them mixed up. Microalloying elements will form precipitates that will retard the grain growth. so u have higher mechanical properties.
From whatever region of the crystal has the highest energy. GBs do have high energy, but you can also get big dislocation pileup that I imagine could induce huge lattice strain as well. So, I'm not sure, but I could see both as feasible.
Yeah, during recovery your dislocation density goes down. The fewer dislocations you have the less repulsion they experience one to another and so dislocations all the sudden can start moving around more easily which means that the material is softer and more plastic.
Yes. However, if you have severely deformed grains due to cold working I think that you will get recrystallization first and then grain growth. If you don't have deformed grains then they can simply grow.
I really appreciate the way you explain these concepts. Examples like the tearing down of the house vs. just fixing it up is the kinds of examples that stick in your head.
thank you! my professor skimmed over this subject fairly quickly, your explanation was quick and simple and helped me understand the process of recrystallization way better!
Wow, what a great explanation. Just what I have been seeking after watching many YT channels on metallurgy. Thanks.
Glad it's helpful!
Nice and comprehensive explanation!
Great explanation! I just will add that the cold work percentage will affect the recrystalization temperature. The higher %, the lower recrystallization temp will be.
The only time a foreigner helped me more than my indian professors -- thank you sir 💞
I did my best!!
I am so grateful to have you.
Thank you so much! Please subscribe and share! I will keep creating great materials content
u teached me more than my lecturers from the past 3 years
Heck yeah
thanks for the great explanation! i wish everyone was like youu!!!!!
Thank you!!
A really great video, thanks a lot.
Hey, professor, thank you for the great lectures, wanted to study material science but never had the chance, so I appreciate the free lessons.
I'd like to ask, if I wanted to find all previously experimented Cu-Fe alloys (%wt, conditions...etc)and their properties for example, how would I go about doing that exactly?
Unfortunately, still have problems with materials databases. They are starting to grow and get better, but there is not one that is completely comprehensive. What I would do, is start with a crystal structured database and look for pure single phase compounds there because you can check them easily. However, this will be for single phases only and I imagine you are looking at multi-phase alloys. In that case you will need to search literature directly. There are probably some review articles that you can start with.
In the cold work amount graph, the grain sizes of the "cold worked" structure are larger than the "original structure".
Shouldn't the grain size of the "cold worked" structure be smaller than the grain size of the "original structure" due to the increase in dislocation density caused by the increase in grain boundaries?
I’m a dental student and we are studying about the material science to know how prosthetics and orthodontic appliances work! Your video was absolutely brilliant and easy to understand thank you 🙏
I have a question will there be a phase where there is recrystallization with no change in strength and hardness? As in my slides it’s mentioned in the hot-working metals there won’t be change in the hardness unlike the cold-working (increase in hardness and decrease in ductility).
I think if the material undergoes recrystallization you will always see a pretty dramatic change in strength and hardness as well as ductility.
So damn helpful, thanks alot! Respect.
Hi, thank you for your video. I have an additional question. The recrystallization temperature corresponds to full recrystallization after 1 hour. What if a hardened metal is constantly at a middle temperature (half that temperature for example) ? Does it still undergo the recrystallization process?
Can you explain how the stacking fault energy affects the ease of grain refinement in certain materials? For instance, in low SFE materials, such as Cu, apparently grain refinement is more difficult than in higher SFE materials such as Fe. What causes this?
You are the perfect 👍
In extrusion, the peripheral grains become larger and larger. In those cases where we don't want the grains to grow, what should we do?
during hot extrusion, the metal recrystallizes as it exits the extrusion die while the material temperature is still > than the recrystallization temperature.. Grain growth can continue post extrusion because the metal is still hot enough for different grain growth depending on the material metals like copper and silver with very high purity will show garin growth after extrusion if the metal remains hot... if the metal is quenched in water as it exits the extrusion die, you can limit grain growth after extrusion
Hi professor, thanks for your explanation of these concepts. Cou;d you please tell me which paper the image "schematic representation of the cold-worked and anneal cycle showing the effect on properties and microstructure" in the video is from?
I don't remember! I put these notes together a few years ago, I apologize that I don't recall where it came from
appreciate thank you; but i do have a question regarding creep vs grain size?
is grain refinement is necessary for creep resistance?
Is there a link to your notes online anywhere?
i may be confused, but i don't think increasing grain size (at least on a monophasic sample) will increase ductility. i think it will actually decrease it.
Are you sure? Have you got a reference?
@@TaylorSparks i don't have any reference ready to give you, but as far as i know, that's why microalloying of steels (with Nb for instance) is so interesting. differently than other hardening mechanisms, decreasing the average grain size doesn't decrease ductility.
the thing is that when you have many smaller grains, the propagation of a crack becomes substantially more difficult than on a coarser grains structure
@@Yodavid1decreasing the grain size will make the mechanical properties of ALL metals higher, higher yield strength, UTS & LOWER elongation. you have them mixed up. Microalloying elements will form precipitates that will retard the grain growth. so u have higher mechanical properties.
If i know each recrystallized temperature and hardness of same alloy, how can i draw that kind of recrystallization prediction grapgh?
Hi Taylor ! after the recovery when the grain growth start , do they start nucleating at the grain boundary due higher energy present at the boundary?
From whatever region of the crystal has the highest energy. GBs do have high energy, but you can also get big dislocation pileup that I imagine could induce huge lattice strain as well. So, I'm not sure, but I could see both as feasible.
after recovery metal might get less hard? what about that
??
Yeah, during recovery your dislocation density goes down. The fewer dislocations you have the less repulsion they experience one to another and so dislocations all the sudden can start moving around more easily which means that the material is softer and more plastic.
For the grain growth equation you said K is times temperature, but then said t is time.
Thank you, it should be time not temperature. K&n are both a function of temperature but in the equation it is K multiplied by time.
What happen to the grain structures when the temperature reaches 7200C?
I don't know anything that is solid at that temperature! All your grains are gone and vaporized into a gas.
@@TaylorSparks its makes sense tho,btw thank you for reply my ques
Bravo
can grain growth happen without recrystallization?
Yes. However, if you have severely deformed grains due to cold working I think that you will get recrystallization first and then grain growth. If you don't have deformed grains then they can simply grow.
How to define the 'complete recrystallization' in practice? HAGBs fraction ＞ 70~75% again after annealing?
Ruining your ice cream !
the video image is too poor, you need to fix it more
Did you select the high resolution option?