@spim randsley okay, then. You can go back your cartoons now and not learn anything. I find these videos fascinating since I'm a professional in a completely different field and never had the chance to learn some of the science this channel explains. I'm sure you can find a video on RU-vid about how to wipe your own ass. Go find it.
@spim randsley yes, I'm pretending to dig a hole....but you're the one actually digging a hole. Don't go there. You're comment was imbecile and that's all I needed.
@spim randsley You know, I was going to ask you the same thing. I seriously would have loved to have been there when you realized that you needed to Google the word "imbecile". Stop being an asshole.
That was extremely well done. At one time I was the supervisor of the chemical strengthening process in a glass plant, but our liquid potassium vat was large enough that we could strengthen glass up to 36x48 inches. A few differences were that we kept the liquid potassium at 650C and we soaked the glass for about 8 hours in a batch process. We also let it cool slowly once it finished the soak. Unlike thermally tempered glass, chemical tempered glass can be cut like ordinary glass, however cutting the glass removed the temper along the length of the cut about an inch or so to each side of the score line. Also a deep scratch in the surface would also remove the temper along the scratch line as well. We would test the process by weighing 1"x1" samples, soaking them in the bath, and then weighing them again after they cooled. We could compute the compression level by using the difference in weight between the samples before the bath (sodium) and after (potassium). The balance that we used to weigh the samples was so sensitive that we could weigh a mosquito. We even weighed a mosquito wing one time.
Your nuts. That type of man knows he's too valuable to risk on strangers. You'll get within proximity and a 400W CO2 laser will grid pattern you to death, or he'll just shoot you in the chest or something less dramatic like that.
Agreed. & Making Viable Claim to Tension Defect,. But torsion was observed. There was no determinate distinguishing otherwise. ...what of fiber glass? Hammers fare well?
Just discovered your channel. I'm a mechanic by trade (but by no means an engineer), so i really appreciate this content. No fussing about, just top notch craftsmanship and science. I tip my hat to you, you are exactly what a true engineer should be like.
The treated glass will resonate with a higher frequency when struck, so this could be used to measure how much substitution has taken place. Perhaps substitution with caesium might enhance the effect, being a larger atom than potassium.
Except that when making steel, it usually starts with "iron" with a high (>2%) carbon content. Carbon and other impurities get removed in the process of making steel. And other metals and maybe carbon get added, creating an alloy. But all of this gets done with liquid metal, not with a solid piece. If you would like to compare that to steel, then look up Carbonitriding.
It's basically exactly how tempered glass works. Cooling the outside rapidly shrinks it relative to the core. Then when the core cools, it tries to "suck in" the harder outer shell of glass and puts the core under tension and the outer shell under quite a bit of compression. I'd be interested to see how this process worked on tempered glass, come to think of it.
I really dig your video production style. Simple, elegant and to the point of the subject. You truly involve the viewer and that is how the best kind of learning takes place. Thank you for doing this.
This video made me break out my old material science book from school and scan through a few topics. There is actually this exact 3 point loading system described in detail; to test the flexural strength of brittle ceramics. Interesting stuff. Had me reviewing defects, slip planes, fracture mechanics for the last hour or two. lol .. cool video.
Very good demonstration. Since the edges are the weakest point, it is important to start with glass that has a clean cut (no chips) or a machine finished edge to make the glass stronger.
I saw a great demo on TV of the effect of defects in glass decades ago. Take about 4 inches of 1/4 inch (say) glass tube and heat it in the center and draw it until very fine. Then mount it in a couple of holes in a piece of wood such that the drawn section is bent 180 degrees. Such a thin piece of glass is very flexible and all is good. However on touching the outside of the bend in the glass with the edge of a feather it immediately shatters. The nascent drawn glass has few defects and the feather introduces some.
The key ingredient for toothpaste used for sensitive teeth is KNO3 too. It is used for filling up the very small tubules in the calcium material (dentine) that lead to the dental nerves. Obviously, it is used at room temperature, but I guess that it is just that KNO3 is especially good for filling up defects in hard materials like silicon and calcium compounds. Great video. Thank you.
Nick Moore - Beware, the "un-breakable beer bottle" will kill people! Beer bottles have a common use in bar fights - and a breaking bottle may prevent a skull injury. Also, it will soon be used as artillery projectile. Fill it with something cheap or heavy, like molten steel or uranium. The only reason not to use tungsten is that is so hard to melt it! And nuke tests will be done again soon! But physicists will be really happy!
0:47-0:48 I still think that is the best part. Just the concern that is shown for safety. Like, it is only a glimpse and not forced into my face and demanded, but it just shows what you do and your precautions that you take. It is a good way to talk kids into being more safer being that most kids rebel when it is insisted upon. Intentional or not, many pros for that bit.
That's... honestly fascinating. I know most types of glass put in public places are (heat?) treated so that when they break, they do so into little cubes as to avoid sharp pieces that could potentially injure someone, but I never knew something like this was possible.
I think this is one of the most interesting videos you made. (Maybe the most for me) Probably I'm gonna use this method for my work. Great job! Keep it up!
Two points (which may or may wnot be pointless): First: There is a superficial similarity between this process and case-hardening steel. In case hardening steel is packed with a carbon source (typically charcoal) and heated in an air-tight container to a temperature well below the steel’s melting point, infusing the surface with carbon to harden it. Making it stronger but more brittle. Second: Whoever first discovered this technique was doing some seriously creative chemistry.
I would view this demonstration as pure Magic if it were not for Physics & Chemistry, still beyond all other considerations itz splendidly Magical! ;-)
"All glass has tiny defects" When I hear stuff like this, I always think about nanotechnology, and what our common, everyday materials would be like if they were constructed perfectly, with zero defects, down to the atomic level. I hope I live long enough to see us develop these tiny engines of creation.
Kind of like post tensioning a concrete house slab. I had one of these when I lived in Louisiana and the soil was very soft. The concrete slab was in compression and did not crack.
Once again a brillant video. keep up the great work. Its almost scary to think what you could get up to if you retired and did they stuff full time. LOL.
Any learned Glass Blower knows that by increasing the wall thickness and tempering process also increases the compression strength there by interleaving the tension stress to the opposite wall of a given cylindrical glass pieces.
You are living the dream man... Taking physics and chemistry I always had ideas of how to apply the stuff I was learning but never had the chance. One day.. I wanna be just like you. Also, I just read a paper on piezoelectric nano technology that applies something similar here. They took a thin layer of Mos2 and bent it like you described to create a current at the nano level. Super cool stuff. Im starting to think I am an engineer rather than a biologist.
All I can see to improve upon would be to somehow reduce the inherent defects of the glass surface, the cracks, somehow. Perhaps another chemical or other solution could be added to this process post potassium saturation to further smooth out or full in those microscopic defects. Not being of a chemistry background or such I don't have any idea there. It might not be possible or even necessary to do my suggestion. If chemically unfeasible then there might be some "mechanical" means to further reduce the small surface cracking via heating, polishing, etc. though the simplest idea I just had was some sort of lamination. A film or another glass layer or such ... but your explanations here and demonstrations too were very well presented, easy to follow, and got my mind thinking about solutions to a problem I haven't ever considered to be a problem to tackle in my lifetime. Thank you so much for the brain workout and your efforts to make an informative well presented video.
This is very cool. The diffusion process seems to only be possible at high temperature though. Since Na ions are smaller than K ions, the glass would need to thermally expand if no pressure is used to cram in the new ions. My bet is that borosilicate glass wouldn't respond as well to this treatment because of its low expansion coefficient. Additionally, you should try this same process under pressure!
Is that a huge capacitor bench I see on the left of the image? Is it for your YAG laser project? Aside from that, it would be nice if, just for the sake of comparison, you weakened glass by ion exchange with a lithium salt! Thanks for making those videos from you home laboratory (which I'm quite admirative of by the way!), you're one of the few youtube channels which provides actual scientific content that has not been completely dumbed down!
Good job, nice demonstration. But I was hoping you would test for the strength of the glass you made also. Adding that would make for a more complete demo experiment.
Great video but there is an error in 5:57 : precompressed members will be not in higher compression in the compressed fiber. The compresion stress will be be the same as precompressed till the external forces increases to a point in which it led the material to a higer compression stress, but till this moment, compression stress will be constant. It is the same for pre tensioned bolts in bolted flanges.
Interesting. I used to operate a glass tempering machine. The end result is very similar. The outside ends up under compression and the inside under tension. The machine I operated used heat instead of chemistry.
Great video, your experiments are truly the best. Any thoughts as to further strengthening of glass utilizing atomically larger group 1 elements? Such as Rubidium or Cesium salts.
Have you tried thermal tempering? You heat the glass in an oven to a higher temperature, then quench in an air blast. This is how many eyeglass lenses were tempered. After that, they are tested by dropping a 1" steel ball from 36".
Great demonstration. That's fine for constant pressure loads, but what about sudden impact like a drop from height. Or something falling onto the glass. Most phones are broken by falls and the such. Just something for you to think about and experiment with.
hi ben, if the strengthened glass is heated and formed to some random shape and back again to a slide then will it still retain the strength or defects will be induced again during the heating and forming process.
What was that word at the end? Amenable or something? Awesome video. To those asking him to test his glass, maybe watch the entire video instead of skipping over stuff. He did it near the beginning.
I've seen this in an old high school chemistry video 25 years ago, but in that demonstration they used an impact test dropping a steel ball from set heights. The effect on impact was far more pronounced then the effect on your static bending load test, though they may have done the treatment a bit different. I'm guessing one is a linear increase and the other is exponential.
Similar to Prince Rupert. I think of defects as holes. Or... Fixed projected dots, or nucleation as in hail clouds concentric circles, or tape that damp sound, or even spinors( that one is like hail Mary). Also granular surface "derivative" tension..not as same as Chladni. Or simply lightning or even silence in musical chairs, "Kerh's transparent stops" ( Ogdoad ).
Applied Science Thanks for replying. BTW thanks also for the incredibly interesting, high quality explanations and demonstrations you provide in so many different areas. Well done!
Experiments on the microscope Cover slides would be my choice of substrate! As would be the use of weight instead of pressure to controllably measure the failure point. After potassium treatment, sputtering with an argon / methane mix would provide interesting results.
What would have been nice would have been to test a piece of gorilla glass in your rig and seen the "difference in strength" with the proprietary method versus the public domain Potassium Nitrate method.
Interesting as always thank you, i wish you would have gotten more in detail about the nature of glass, what it is and why can't the defects be removed from the "structure", how glass is more or less by opposition to crystal and how glass is produced, not necessarily in detail but an overview on what glass is, what are the characteristics and how it is produced through applied science :)
It's cool to see you working with glass It would be interesting to see if you could figure out a diy coating system To help with flare and chromatic aberration on old camera lenses that didn't originally have coatings.
The medium temperature used must have induced a devitrification too. So the crystalline properties are not exactly similar to the starting glass, thus the effect is not purely chemical.
