This is the first time (in 69 years and now 70) that I have ever understood something intuitively in metallurgy! Most discussions of metallurgy concepts tend to give information of various effects, but no real explanation. Thank you so much.
Ralph Dratman I’m not surprised that for at least 5 of those 68 years you didn’t find metallurgy intuitive (not that most 6-year-olds grasp metallurgy either) 😅 😉
Make the demo sheet flexible somehow, and it may visually demonstrate plasticity too. Not sure how I'd bend it on the same plane as the bearings, though, which would be the best demonstration.
That's interesting. The liquid you poured from the beaker at the end turned into a gas after pouring and then quickly condensed back into a liquid again.
I’m a materials science major, and I always find myself coming back to this video and the last one to hear about crystal lattices and their properties. Everything is, to the best of my knowledge, quite precisely-worded and accurate without sacrificing the accessibility of the language or concepts. And those videos of the vibration causing the lattice to shift around? Phenomenal. What a beautiful visualization. Thanks for making this video! I owe the fact that I do what I’m doing right now partially to science communicators like you.
I know there's a year gone by since your comment, but aVe has a great video describing the phase diagram of steels, what it equates to physically, and the molecular/grain structures corresponding. It is one of only 3 or 4 videos, this one included, that has been so intuitive to digest.
This is by far the best explanation of mettalic plasticity that I have ever seen, very easy to understand and not bogged down by the other "side effects" because you avoid them in a careful and well thought out way. 10/10 Steve
Hey Steve. I’m a metallurgist in the United States and I really appreciate the videos you’ve done on crystal structure and how it relates to metals and their properties. I may just share this vid with our team to help explain metallurgy to the non-metallurgists I work with. Thanks for sharing
Does this video then also accurately explain why you can only bend a piece of metal so many times? Because the imperfections are no longer spread out enough through the metal, causing it to break instead?
@@nareik8017 there is a lot lacking from this model. It is a nice way to show how crystals and imperfections form and why some of them don't seem to be bothered by low heat (or kinetic energy here).
As steve explained, when you exhaust the plastic limitation, that is the glide of dislocations and point defects, you can initiate cracking, but a lot of metals are ductile at room temperature, meaning a crack wont necessarily cause complete failure, often a crack can be within a grain referred to as a microcrack, and you repeat the deformation process, you generate more microcracks which can accumulate and weaken the structure, eventually leading to complete failure. This also is a simplification and there are many mechanisms why cycling loading can cause failure.
Sort of . If heat is slowly reduced then ductility is maintained . But. If temperature is rapidly removed then grains form and solidify rapidly causing hardness (mohs) and brittle characteristics . This is where the metal fun goes off in the ditch . Its a balance of desired traits that an engineer or metallurgist are a seeking . It gets really nuts when alloys or base metals are changed from iron ( steel) to tungsten, titanium , and aluminum .
normally yes but also depends on the alloy , some high cromiun steels become less ductile with high heat and tend to break , steel alloys are amazing with little variations in materials and heat treats the properties can be completly different
As a student studying material science and mechanical engineering, this has to be my favortie video to date! That dislocation at 2:29 was incredible! Thanks for the fascinating content steve!
Oooh, now I'm wondering if one made with differently sized disks (so they'd fit nicely within the same depth) could be used to show grain structure within alloys.
I was thinking how difficult it would be to get correctly spaced plexiglass. Then I reread you comment and you said discs. You could probably do something like that with metal washers. Hmm
Diamondflow , that is a great idea. I did that in a simulation video. "Primordial Particle System - The Trailer". That one shows the metallic structure. But "heart beats and blood flows" shows the different diameters (each color had a different radius and also different velocity). I think you and gizmoguyar might really like these 2 videos.
People working in granular physics do that a lot the problem is you get very large friction between the discs and the plates. A really cool and interesting thing I did once was to work with photoelatsic discs, the beauty is that they allow you to see the force chains inside. www.eurekalert.org/multimedia/pub/115882.php
Materials was my favorite subject during my engineering degree. I was one of the weird ones who really enjoyed learning about crystalline structures and defects, and how to achieve the material properties you want in an alloy. I just find the subject fascinating.
I also loved the class too. I thoroughly enjoyed the labs because we got to use different machines to determine the different characteristics of a metal (like hardness, tensile, and shear strengths), and we were able to use different treatment and quenching techniques to see how it impacted the characteristics of the metal, whether that be steel, aluminum, or cast iron. The only part I didn't really care for in the class was all the different units and measurements. It makes sense why there would be so many, but it was always hard to remember what each number and letter represented what when it came to units and measurements of a certain metal.
Hi Steve! I'm a grad student studying the transition of Opal A from diatoms all the way to quartz in the earths crust, which is to say to transition from amorphous silica to crystalline quartz. This is such an incredible description of that process that I actually showed your video to my advisor who then showed his class! I use X-ray defractometry (XRD) to determine the spacing between atoms based on the angle at which they defract x rays in order to identify the minerals in my samples. Since you love resonance and crystallization, I thought a video in which you break down how we can use x-ray defraction to determine crystal structure sounded like your bread and butter!
Eons ago, when I was still a young man, I worked as a heat treater. Who knew how many different types of steel there are? Some harden in oil, some in water, some even in air. It was quite a learning experience. I would never have guessed that the dew point inside the furnaces was an important factor in the successful hardening of steel, but it was one of many things we had to keep track of.
I'd love to see Steve explain those hardening treatments inna video of this sort. I don't know the technical name in English when you put red hot iron in burnt oil and the outer layer turns into a kind of black anodized steel
@@Malakawaka Explanations of the process can be found online. I don't remember specifics, but it has to do with rearranging the crystal structure of the steel, turning it from austenite to martensite.
This is a big question. From the basics, assume atoms are balls (bearings), balls can stack on top of each other, think of it as layers of whats shown in the video. If the layers lying on top of each other follow a regular repeating pattern, they are called Crystalline, or crystals. However, atoms might not always arrange in the same fashion. The differences between these are called crystal structures, where the distance between neighbouring atoms can change. So a single metal can have different crystal structures, these can then be named “phases” of the metal. Alloying elements can also affect crystal structure, imagine trying to squeeze a carbon atom between 10 Iron atoms, it will distort the distance between the iron atoms. So far, metals can have different phases based on a repeating crystal structure which alloying elements can affect. Next, stability. The carbon atoms will have a position within the Iron matrix where they are most stable. But when you heat material, expansion occurs, magnetism changes and phases can also change. All these things allow for the stable positins of allyoing atoms to change, suddenly new positions are occupied and considered stable. Cooling, if you allow the hot alloy to slowly cool, it will return by to the same original phase. If you let the sample heat up to allow grain growth as Steve described, this is annealing. Normally generates softer and more ductile materials. If you cool rapidly, there is insufficient time to allow the alloying atoms to redistribute back to their stable positions, and they become trapped! This trapping forces the microstructure into what is called meta-stable phase. This phase, if given sufficient heat and time, will revert to a stable phase. For simple Iron Carbon steels, this how Martensite, the super hard but very brittle phase is formed. This trapping of atoms in metastable positins strains the metal matrix, the binds between atoms, in such a way that restricts dislocation glide, which prevents plastic deformation. So, metals have phases, phases change at temperature, cooling slowly allows a return to original phase, cooling rapidly allows a formation of a different phase, often thought to be harder Theres a lot more to talk about here….. a lot But thats the idea, if you cool at different rates you can generate different crustal structures which the material properties are highly dependent upon
If you've done any research on Google concerning your paper then it's not such a surprise that this video is in your recommendations , yesterday I was having a phone conversation some one and mentioned about my experience working in a metallurgy research lab , and guess what this video comes up in my recommendation.
@@drinkthekoolaidkids Careful of confirmation bias! Typing something in to Google then getting a suggestion, fair enough. But saying it aloud then getting a suggestion, I'm still not convinced. But if I read in to your comment that you hadn't come across Steve before, welcome :)
Achirag, I made a few videos where I vary more parameters like radius and velocity. Search "Primordial Particle System - The Trailer", there is another where I got heart beat behaviour!
As a materials engineering student, it's cool to see matsci and metallurgy showing up more in edutainment spaces. Seems like it's becoming more popular overall
3:00 the gravity here plays important role - while you hold this toy vertically it simulates gigantic pressure coming on bottom of metal plain, i guess. or maybe the temperature is like very low with very little attraction between single atoms. I keep watching, maybe you answear this further in the video lol :)
I think you could imagine the grain as a net. The larger the spacing is in the net, the easier it is to escape, or in this case, bend out of shape. With a smaller spacing being harder to escape/bend out of shape.
Derek and paynoattention, I did a few videos on this too. I even varied radius, and speed of different particles in the same simulation. I think you might like these experimental videos. Search "Primordial Particle System - The Trailer", there is another where I got heart beat behaviour!
When I served my Tool and Die apprenticeship, under my father, I learned about Space Lattice..Austenite and martensite. I have known and felt what you are demonstrating here for my entire 42 year career. I have heat treated, hardened, tempered, stress relieved and annealed and this is the first time I’ve seen what I know, demonstrated perfectly. Thank you so much. I’ve told my apprentices over the years that you have to think like a molecule in order to properly handle the machining of steels..
Stress Relieving. We used to do mechanical stress relieving with a piece of equipment called Formula 62. Plus when teaching apprentices about machining I always found it helped to get out my metallurgy books and show them micro graphs of just how metals cut. They never cut at the tools edge. They tear in front of the tool.
As a Metal fabricator/welder, I've sat through a lot of lessons on metallurgy. First time I've heard about dislocations and their implications. I'd like to thank you and your balls of steel, Mr Mould, for this moment of clarity.
Reminds me of elementary school in the late 60's, take a large paper clip, straighten it out then bend it in half, closed then open really fast, done just right the metal gets hot, just before it breaks touch it on the back of your friends ear. Done properly you can get the clip nearly red hot
By bending it repeatedly you create more and more of these imperfections, so the internal stresses get higher and higher, and eventually they're stronger than forces that keep it together and it brakes
@@trapper1211 By his explanation, it's not creating imperfections; bending the metal works those imperfections out of the grains and into the grain boundaries. This leaves you with more stable (harder) grains and greater separation between them (since you've moved the voids into the boundaries), so any flex has to come from moving the grains in relation to each other instead of changing their shape. That's a recipe for brittleness. Think of a sand castle: it takes more force to deform a grain than it takes to separate the grains from each other. Once you start trying to bend any part of the castle it'll shatter because the grains separate instead of deforming and you get catastrophic failure.
@@mailleweaver i really like your explanation! I was just wondering if the voids created by dislocations migrating to grain bounderies could be used to strengthen the metal? Like if after plastic deformation u heated the metal just enough for the grains to move and spin freely they would eventually settle in a position where the grain bounderies fit into each other like lego blocks. This would mean u would have to break regular lattice interactomic bonds to get grains to slip around each other and seperate.
@@ayhamsaffar8407 I mean if you bent the metal and heat treated it, you would strengthen it in that particular shape. I don't think it would do what you asked though.
I know I'm late to the party, but this last year I was at college for Mechanical engineering, and had a class on material sciences. We used homemade Atomix toys to do exactly what this video is showing!
Within it's limited scope, this is the best introductory (or refresher) explanation of metallurgy that I have ever come across. This will help grok metals, rather than just pass the exam.
You may remember a few years ago, Apple made a big deal about replacing the cover glass that they use with sapphire in order to reduce breakage. Fundamentally, Apple confused hardness (sapphire is harder than glass) with toughness, the ability to resist breakage. I turns out that the glass they were using was tougher than sapphire so the entire exercise was pointless.
Actually, you can demonstrate other properties with that (or similar) model (I did it at uni with soap bubbles). Take a look at what happens when you introduce larger or smaller particles to help understand alloys
I'm an audio guy from way back when cassettes first came on the scene, and I remember when some manufacturer, maybe AKAI, came up with "Glass Ferrite Heads" and how they were so called "impervious to wear"... You're explanation and demo really gives insight to the metallic structure of those type of heads. I still own machines with "Ferrite" heads, and after more than 30 years, they barely show any wear. Of course, they do wear, but to such a small degree compared to softer "Permalloy" heads, which are more common, and probably cheaper to produce.
... so if you cast a molten metal (beyond crystalisation point) into a form which is vibrating with the resonance frequency of the (cold) piece to be cast and let it cool down over the crystallisation point real slow, would you get a monocrystalline piece of metal... ?!
No, because depending on the geometry of the cast piece it might be practically impossible to determine or generate the proper frequency, but also because the casting will shrink as it cools, which means you'd also have to compensate for that in your applied frequency. To grow large single crystals we use can use techniques like epitaxy or the Czochralski process. The latter is used to grow the silicon for pretty much every CPU and GPU in the world, along with any other IC with feature sizes so small that grain boundaries would cause electrical problems.
Monocrystalline alloys do exist and are used in the very hottest components in gas turbine engines (single crystal nickel superalloy turbine blades). They are formed using something called a grain selector - the molten alloy is poured into a mould on top of a solid piece of alloy at the bottom (called a 'starter') whose grains are all aligned in the same direction (the starter is 'directionally solidified', a technology previously used for turbine blades before single crystal was developed). The grain selector has special geometry that only allows one single grain from the starter to travel through it. Using the very slow cooling you described, the mould is cooled from the bottom up, i.e. from the starter, and this single grain grows through the selector and up along the full height of the turbine blade. The purpose here is a little different than you might guess from the video - it is to prevent creep, or sliding of grain boundaries at high temperature. if there are no grain boundaries, they cannot slide against eachother. However, dislocations still exist, so the alloy has lots of different alloying elements that are added to prevent dislocation motion. It gets very complicated, very quickly with nickel superalloys! But it is fascinating what you can do with alloys and heat treatments.
Teacher : "Okay class today we are watching a video about the process of heat treatment in metal." Steve : "Yea.. jiggle those balls, jiggle 'em, make 'em hot!"
This video is brilliant!! I think I understand the process of "Work Hardening" a little better now - such as repeatedly bending a copper wire will increasingly become more difficult, until it eventually snaps. I may have gotten this wrong but from what you've explained I'm guessing that the dislocations within copper grains disperse bit by bit to the grain boundaries until the copper breaks. I could also he totally wrong 😅
Wow, can't stop watching your videos. I really need to know where you made the animation at 4:34, it looks great and it would change the way we teach semiconductor theory at my university.
What I found fascinating is glass used by zeiss is heated up and very slowly over a WEEK to slowly cool down so as not to cause stress lines that would impair the ability of light to move in a straight way through the glass of lenses making it a faster lens... IE the FStop of the lens. The lower the f stop the better the light transmission How clever is man!!
That's interesting! However, I think there's a slight correction to be made. The "speed" or f/ratio of a lens is the ratio of the lens' focal length to the diameter of the aperture. The heat treating you described must improve the transmittivity and general optical quality of the lens, but would not make it a faster lens, i.e. give it a wider aperture.
Wow! What a great teacher u r! I was confused for whole of my engg. About this topic kindly make more videos like this. These may be very helpful for engg. Students Great way to arise intrest in engg.
Hmmm ... quenching is relevant mainly only to steel, where it is used to trap relocated carbon atoms so they remain, at room temperature, in a place they normally occupy in the atomic lattice only at very high temperature
@@Gottenhimfella but most (if not all) materials form smaller crystals when cooled faster. I believe it's because the atoms don't have time to form in to larger ones.
What if the container was a hexagon, an octagon, or a circle? What if there was a thin separator that blocked a small area of the field? Can you “dope” the field with small separators (or a fixed bearing) to change the structures of these lattices in interesting ways?
When you shake the model and drop it abruptly into place, that's quenching. Historical heat treating and annealing is about controlling the speed of that drop as well as a bit of careful jiggling to get to the sweet spot of brittle hardness vs flexible softness for the intended purpose.
1:04 this behavior can be used to demonstrate how the surface of the earth moves and shifts to make its continents. but with the definition of the lad height defined by the larger clumps and the more individual noise being underwater.
