5 ms·
Cool. What would applications be here? Could we for example make basic alloys of vehicles, railroad tracks, and refrigeration systems more resilient when they u
by lr4444lr 3y ago
Cool. What would applications be here? Could we for example make basic alloys of vehicles, railroad tracks, and refrigeration systems more resilient when they undergo temperature variations, and therefore last longer?
- bediger4000 3y agoTraditionally, holding optics or some other delicate sensors that we want to stay aligned, or at least point in the same direction consistently.
- ScoobleDoodle 3y agoBlackbird SR-72? SR-71 leaks before take off in anticipation of the thermal expansion plugging everything up. https://nodum.org/was-sr-71-blackbird-leaking-fuel/ https://nodum.org/was-sr-71-blackbird-leaking-fuel/
- brilee 3y agoThe heat generated by drag at such high speeds means that titanium was, at the time, the only suitable material due to is high melting temperature.
- barelyauser 3y agoNot high melting point but its ability to remain strong at high temperature.
- hinkley 3y agoAn annealed aircraft is not a particularly safe aircraft, yes.
- sadhorse 3y agoOnly precision applications can afford the high cost of specialized materials. All the things you mentioned are unrelated, as they are cost driven and steel will always win.
- nuancebydefault 3y agoFrom the understanding of the mechanisms that cause this invariance, many other applications could be derived, that even don't need the invariance property. For example materials of which cooling systems (e.g. Peltier-like) can be made. Also their measurement methods seem pretty advanced and could be used within other research like in the area of nano technology.
- mitthrowaway2 3y agoYes, the main value would probably be in better understanding the temperature / pressure / volume / magnetism relationship within invar-like materials. Perhaps the result will be new piezomagnetic applications, or magnetocooling applications, and so on.
- Cthulhu_ 3y agoWell, they knew the effect existed, so applications are already in use; this just explains the how, which I'm sure makes the effect more predictable - and allows for researchers to find more alloys with this effect in a focused manner, instead of via trial and error. As for applications, it probably won't be garden variety appliances, thermal expansion isn't much of an issue there and designs for all of the things you mentioned have been tweaked a hundred years ago to deal with thermal expansion (although railroad tracks are still an issue sometimes). And of course there's other parameters, like wear resistance; nickel is a pretty soft metal I believe. But, things like precision industry or space will find a use for this. Sattelites have to deal with hundreds of degrees of temperature variation.
- _yb2s 3y agoI disagree, even modern cars have a lot of unsolved problems with thermal expansion and cracking causing failures of cylinder heads, gaskets, exhaust manifolds, turbochargers, etc. It may be solved in principle, but certainly not in practice.
- barelyauser 3y agoThere are problems that are game stoppers and there are problems that are unavoidable. Cars work. Yes, if you drive 1 million miles you will have cracks in the engine due to thermal expansion, but who cares? Make a new engine and get over it. Now consider a space elevator. Material problems are a game stopper.
- MichaelZuo 3y agoThese problems are already solved for very high end aftermarket exhaust systems, which use Inconel.
- dublinben 3y ago"Modern" cars run on electricity and don't have any of those parts or their corresponding problems.
- buryat 3y agowho needs to read the article? > That anomalous behavior makes these alloys useful in applications where extreme precision is required, such as in the manufacture of parts for clocks, telescopes, and other fine instruments.
- Ellentonnq 3y ago[dead]
- golem14 3y agohttps://en.wikipedia.org/wiki/Invar https://en.wikipedia.org/wiki/Invar gives a few hints.
- burnished 3y agoNo need - you ever cross a bridge and note a mesh of metal teeth? Thats for thermal expansion. Its already designed around and isnt generally noticeable - for steel it is 0.0000065 / °F [0]. [0] https://www.metalsales.us.com/thermal-expansion https://www.metalsales.us.com/thermal-expansion
- loeg 3y agoWould be nice to not have the holes though.
- burnished 3y agoWhy is that? I've already put all my knowledge on the topic on display so I can't tell if this is a joke about aesthetics or if there is actually something neat having to do with the gaps
- hinkley 3y agoI know from tales of professional cycling that those metal bridges are vastly disproportionately responsible for broken bones. They're also squirrely when wet, and if you've ever ridden across one on a bike or a motorcycle, they are fucking terrifying because you can see the river below you, and the railings for some reason tend to be very low. And while I understand that many bridges don't really prevent runoff into the water flowing beneath them, metal mesh bridges really can't.
- maxbond 3y agoI'm not sure you're talking about the same thing though, I think they meant these thermal expansion joints, not necessarily a bridge made from metal mesh: https://i.pinimg.com/originals/4d/82/91/4d8291e022bd14c87985df11fad1be1e.jpg https://i.pinimg.com/originals/4d/82/91/4d8291e022bd14c87985... I know that picture is a mesh, I thought it had the best detail, but they're on paved bridges too: https://siamagazin.com/wp-content/uploads/2018/03/23h32h-min-1.jpg https://siamagazin.com/wp-content/uploads/2018/03/23h32h-min...
- metal_am 3y agoForms and tooling for composites are a big one in the aerospace world. Keeps dimensional stability better through autoclave cycles.
- hinkley 3y agoI was going to say something similar but then I started having doubts. For precision instruments you probably want devices that have exactly the same modulus of expansion as what you are cutting. So that 0.15m is always 0.15m no matter the temperature of the factory. For molds you would want the outer mold to shrink slower than the molded material, but would you perhaps not want an inner mold to shrink faster? So that the material pulls away from both as it cures/cools (I'm asking, I don't know)?
- bluGill 3y agoProbably not. You typically cannot change one variable in isolation with an alloy, so while you can gain in one area other things change as well. Strength - both compression and tension, hardness, resistance to bending, springiness, melting temperature, are just a few of the properties (note that the properties have engineering names and common names - I mixed with no concern so there is duplication)
- Terr_ 3y ago> That anomalous behavior makes these alloys useful in applications where extreme precision is required, such as in the manufacture of parts for clocks, telescopes, and other fine instruments.
- JKCalhoun 3y agoTangent: reminded me for some reason of the lengths (ha ha) clock makers went to to account for the expansion and contractions of the clock pendulum. To keep consistent time the length of the pendulum too needed to remain constant. Enter the brilliant John Harrison: https://en.wikipedia.org/wiki/Gridiron_pendulum https://en.wikipedia.org/wiki/Gridiron_pendulum
- twism 3y agoautomatic weapons