Recovery, Recyrstallization, and Grain Growth

Рет қаралды 32,269

Күн бұрын

As metals are deformed and then heated they undergo recovery, recrystallization, and grain growth. The hardness, yield strength, ductility, and grain size all change wildly during these processes. Old, deformed grains are replaced by defect-free grains which grow over time via Ostwald ripening.

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@zacharyrussell992 2 жыл бұрын

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.

@alfredolozano9801 Ай бұрын

Great explanation! I just will add that the cold work percentage will affect the recrystalization temperature. The higher %, the lower recrystallization temp will be.

@lesnerchai2186 3 ай бұрын

I am so grateful to have you.

@TaylorSparks 3 ай бұрын

Thank you so much! Please subscribe and share! I will keep creating great materials content

@brianbender7438 8 ай бұрын

Wow, what a great explanation. Just what I have been seeking after watching many YT channels on metallurgy. Thanks.

@TaylorSparks 8 ай бұрын

Glad it's helpful!

@BLADE_PLASMA 6 ай бұрын

The only time a foreigner helped me more than my indian professors -- thank you sir 💞

@TaylorSparks 6 ай бұрын

I did my best!!

@suheladesilva2933 Жыл бұрын

A really great video, thanks a lot.

@user-rr1rs3my3o 2 ай бұрын

You are the perfect 👍

@haozhengwang1196 2 жыл бұрын

So damn helpful, thanks alot! Respect.

@zouzouatallah3321 10 ай бұрын

thanks for the great explanation! i wish everyone was like youu!!!!!

@TaylorSparks 10 ай бұрын

Thank you!!

@NoName777I66 Жыл бұрын

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?

@Prince_Sharming 2 жыл бұрын

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?

@abidabdu986 Жыл бұрын

appreciate thank you; but i do have a question regarding creep vs grain size?

@DONG-MINKIM 2 жыл бұрын

If i know each recrystallized temperature and hardness of same alloy, how can i draw that kind of recrystallization prediction grapgh?

@ambaro0887 Жыл бұрын

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?

@TaylorSparks Жыл бұрын

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.

@imanmahamade7725 3 ай бұрын

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).

@TaylorSparks 3 ай бұрын

I think if the material undergoes recrystallization you will always see a pretty dramatic change in strength and hardness as well as ductility.

@vagrant_gypsy Жыл бұрын

Bravo

@abidabdu986 Жыл бұрын

is grain refinement is necessary for creep resistance?

@2xll852 10 ай бұрын

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?

@TaylorSparks 10 ай бұрын

I don't remember! I put these notes together a few years ago, I apologize that I don't recall where it came from

@evanward9552 Жыл бұрын

Is there a link to your notes online anywhere?

@picturesfile4635 2 жыл бұрын

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?

@thomaschandler2153 2 ай бұрын

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

@_abhishek.sinha_1 Жыл бұрын

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?

@TaylorSparks Жыл бұрын

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.

@potemkininstall9327 3 жыл бұрын

For the grain growth equation you said K is times temperature, but then said t is time.

@TaylorSparks 3 жыл бұрын

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.

@azmirulaiman4330 3 жыл бұрын

What happen to the grain structures when the temperature reaches 7200C?

@TaylorSparks 3 жыл бұрын

I don't know anything that is solid at that temperature! All your grains are gone and vaporized into a gas.

@azmirulaiman4330 3 жыл бұрын

@@TaylorSparks its makes sense tho,btw thank you for reply my ques

@ujwal560 3 жыл бұрын

after recovery metal might get less hard? what about that ??

@TaylorSparks 3 жыл бұрын

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.

@Yodavid1 3 жыл бұрын

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 3 жыл бұрын

Are you sure? Have you got a reference?

@Yodavid1 3 жыл бұрын

@@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

@doddyalexander1 3 жыл бұрын

@@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.

@doddyalexander1 3 жыл бұрын

can grain growth happen without recrystallization?

@TaylorSparks 3 жыл бұрын

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.