19
This car crash in a parking lot caused a Cybertruck to have an unscheduled rapid disassembly.
(hexbear.net)
There’s a story in the news right now about someone crashing into seven parked cars at the Dallas Stars parking lot but the part I’m interested in is how this somehow ripped a cybertruck in half?? Like clean in half??
https://bsky.app/profile/ladyemily.nebula.tv/post/3lljueafogc2z
cast aluminum ‘frame’ - glorified beer can. cast/poured versus forged/rolled. Forging or rolling creates a superior product versus pouring molten metal into a form. A metallurgist could expound on that for quite a while I’d bet, my understanding is skin deep at best here. Also, aluminum tends to shatter/explode suddenly versus steel/irons tendency to plasticize.
There’s a reason we tend to use the type of frames we use when building trucks; body-on-chassis/frame, and not unibody/monocoque types. There’s a reason those vehicles also have steel as the backbone.
Two heavy duty rails run the length of the truck, with cross members bolted/welded/riveted to it. I think the dumpster is technically a unibody frame, which is body panels, flooring panels and overhead panels welded together to make a cocoon of sorts, but forgoes the two rails that do the real load handling. Meant to be light, nimble, compact, which is traditionally none of the things a truck is intended for.
Looking at photos the dumpster’s frame is a formed, but realisitically flat piece of aluminum, with a basic shell attached to that, that the body panels are fucking glued to.
‘Speed tape’ used by pilots to temporarily patch holes in the sheet metal, probably offers more structural rigidity that the dumpster does.
Fuck, the body panels are of tougher material that the fucking frame is.
I don't think this is inherently true. You need to skin castings to remove voids and inclusions but if you're doing work after this I think it is more complex than one just being superior.
forging/rolling removes voids and creates denser grain. you end up with a better product.
I don't think that makes much difference for something that gets heat treated (because grain structure & size both change). And there is a whole lot of residual stress that comes with forging/rolling thta may be significant depending on what you're doing.
The induced stresses are part of what can make forged parts stronger iirc (used to work as a designer with a metallurgist as a colleague but, like, many years ago with an intervening drug addiction, recovery, and uni degree so my memory of the technical details is... Imperfect). But yeah it's a complex topic.
yes, I believe it is the mechanism behind cold working and peening, but I don't think it changes the grain structure. Definitely a complex field that I am only barely familiar with.
I'm sure it behaves differently in aluminium vs steel, too.