Now that makes sense. Nickel would drastically aid in heat resistance and strength, allowing for less carbon steel to be used. To answer your question, yes. Now stainless is used in aircraft, but not usually the whole thing. Nickel would allow for less skilled workers, such as in Russia, with worse equipment, to still get the job done
Mikoyan MiG-31 - Wikipedia
en.wikipedia.org
I guess nickel steel is easier to weld then chromium-based stainless?
I imagine that designing your weapons of war to be easily made by less skilled workers may pay dividends. American weaponry is very high tech, but that also means fiddly little parts that are difficult to make. I worked for a machine shop where they had to make these 2" long Inconel tubes that were maybe 3/4" diameter and had a 1/2" bore, and at the bottom of that bore was a complicated shape that required special tools to turn, and they had to be so perfect with a perfect surface finish that each piece required cmm testing and visual inspection with a microscope, and still had about a 40% scrap rate. But if they weren't perfect they would burst under the hydraulic pressure they were expected to handle. Our shop was the only one in the world that would even touch them and we absolutely hated them. I don't recall exactly what they were for, but they constitute a very expensive point of failure for whatever they were for.
It really depends on what you're going for. The mig 31 is to go high and go fast. It can take some extra weight from heavier alloys. The F-15 does all of that and dogfights with a 2:1 thrust ratio. It needs to be light. Hense Russia has a lot of specialized planes while the US is more standardized; you get what you pay for. China is somewhere in the middle by most appearances
Strain doesn't magically disappear if you use screws instead of welding. For a given loading it is the exact same regardless of fastening method.
Antonio Ferri got the initial idea, we "just" did literally everything else, all the billions invested into actually making it work.
We are already building semiconductor plants here so we wont have to.
Yeah, and they didn't shit the bed like we did in 2008 which is exactly my point: most of their economy isn't a bunch of made up numbers which is how they managed to compensate for complete fuckups like evergrande.
The Germans spent millions of reichsmarks developing the swept wing then the USA literally stole all the research.
The official speed for the F-15 is Mach 2.5+. It goes faster, and uses more than aluminum. Different areas heat at different rates. And judging by what's listed for the percentage of materials, I fully believe that instead of making the entire plane out of stainless or titanium, they placed the heat resistant material where needed to reduce weight. That's called smart design. Further supporting my theroy is that they keep fitting bigger engines, just look at the EX and Saudi variant. It can catch a Foxbat, of that I have little doubt.
The only F-15 that has gone Mach 2.5 plus. Was the streak eagle. A F-15A, lightened and modified for altitude record setting attempts.
I'm willing to believe that there's a fun button especially with the upgraded engines, even if it can't keep it up for long. In any case, it was built to kill the MIG 25, and still holds the record for most successful jet in terms of kill loss ratio.
This is what non-stop military propaganda does to people.
Yes... and? I'm speaking from my manufacturing background that going beyond Mach 2.5 is fully possible, it's not a pure aluminum jet.
That's what I'm kind of saying. Despite being officially listed as Mach 2.5, like those examples you put out, I could easily see it going beyond that judging by history. Probably not recommended, but I imagine it's like the old War Emergency Power; if you need it you have it.
I don't think you have a clue what you are talking about. No aircraft with aluminum as a significant part of its structure is hitting Mach 3 without a ton of fancy thermal management.
are those calculations assuming that the wings will immediately liquify the moment the plane exceeds the speed limit, or does it require sustained loads and thermal accumulation?
The fact is it was built to catch up with the Foxbat. Normal speed is Mach 2.8. The stated goal of the F-15 program was 2.7. Aluminum doesn't liquefy instantly my guy. For short periods, as in catching up to a MIG 25, it could probably pull it off. The SR-71 was designed for SUSTAINED Mach 3 operations
Where did I say anything about Aluminum "liquefying"? I posted a graph showing that the compressive strength of aluminum drops as temperature increases. You understand what that means, right? The properties of a metal are tied to temperature, something a welder should understand.
It might be propaganda, but I've heard that the F-15 has only once faced a MiG-25. They saw each other, the F-15 turned to chase, the MiG turned to evade, opened the throttle to full, and left the F-15 in the dust. Those engines are no joke.
No shit it's strength is going to decrease. It's aluminum. I'm saying that for a short time it can open up past 2.5. And until they drop the + behind the 2.5, I am going to assume it can hit 2.7 for at least some period of time. It certainly has enough thrust with modern engines to do it. Them "dropping" it sounds like a way to create confusion.
The only thing the 25 was designed to be good at was intercepting high altitude Mach 3ish capable nuclear bombers. Which the US ended up never building anyway past a couple prototypes. Getting it up to that speed and altitude would burn out its huge engines anyway, so they put in governors or whatever that limited it to Mach 2.8. Theoretically it could get up to 3.2
