You can work glass and plastic the way you can because at a certain temperature range their plasticity and viscosity are conducive to working them in that manner.
Iron has plasticity at a temperature, but lacks the viscosity until it gets too hot to have the plasticity needed. If you had a molten blob of iron in space and tried to inflate it, the material would get a hole blown in the side instead of inflating and stretching out because the working properties aren't right.
What if the substance was only one part iron?
An alloy would have to have the working properties needed, but all "metals" have the same problem of viscosity and plasticity not overlapping.
That would no longer be iron, then. It would be an alloy. Steel is the most common example of an iron alloy and it exhibits different properties based on the ratio of carbon and other elements.
Ditto goes for most alloys. Glass-like properties aren't typical, otherwise metal blowing would be a thing.
There might be alloys that can do this, but not the usual ones. Some of the low-melting ones can be gooey-seeming, off the top of my head.
It would take substantially less energy to make metal molten in space. As air pressure drops, the temperature needed for materials to change states becomes lower. That's why water boils much faster on a mountaintop than it does at sea level.
The metal would be manually workable at relatively low temperatures. Without air, you would need a tank of a gaseous substance to “blow” into the metal.
Melting point doesn't work like boiling point. Otherwise, what would we make rockets out of? They get really hot in a vacuum, but need to (and do) stay solid.
If you go to really high pressures like in an ocean trench or deeper, melting points will raise too (or lower, in water or silicon's case), but 1 vs. 0 atmospheres is negligible. I haven't seen it even mentioned in any vacuum engineering stuff.
While it’s true that the relationship between melting point and boiling point differ from material to material, the melting point always remains below the boiling point until the triple point.
The triple point is when the ambient pressure is low enough that a substance can be solid, liquid, and vapor in equilibrium at the same time.
As for engines, they burn at temperatures hot enough to melt the steel they are made of, even while on Earth. Engineers employ regenerative cooling to prevent the housing from melting at such high temperatures.
They still get very hot, though.
Another example: Every incandescent lighbulb. The filament is stupid hot in there, under a rough vacuum, and doesn't melt. I would be surprised if 1 bar even amounted to a full degree of change in melting/freezing point.
Water is volatile, and so it's a better example of variability at familiar scales. You'll notice the freezing point is pretty much vertical at 0C on the phase chart until 100s of bars. (And then gets lower because pressure pushes matter towards denser states, and ice I is, unusually, less dense than the liquid)
The triple point shows up when the boiling point lowers to meet the melting point, and liquid water ceases to exist as a stable substance. It's at ~0C.
Why would you need to go to space to try this? And since you're thinking in space, how would you cool it down?
Space is cold, the question is how would you keep it hot?
Space is cold, but since it's a vacuum (a great insulator) keeping things cool is a greater challenge.
Sure, but temperature is useless in a vacuum. The heat has nowhere to go. There is some ambient radiation in space, but not enough. Temperature regulation is a serious thing for astronauts.
Things still do cool in shaded space, though, it just takes longer. The James Webb took like a month or two to get down to cryogenic IIRC.
I have a feeling OP was worried about gravity, which isn't usually helpful here, but isn't actually a dealbreaker. Glass is heavy too.
I have not invented antigravity. If you have any pointers, I'm all ears. /s
Community Rules
Rule 1: Be respectful and inclusive.
Treat others with respect, and maintain a positive atmosphere.
Rule 2: No harassment, hate speech, bigotry, or trolling.
Avoid any form of harassment, hate speech, bigotry, or offensive behavior.
Rule 3: Engage in constructive discussions.
Contribute to meaningful and constructive discussions that enhance scientific understanding.
Rule 4: No AI-generated answers.
Strictly prohibit the use of AI-generated answers. Providing answers generated by AI systems is not allowed and may result in a ban.
Rule 5: Follow guidelines and moderators' instructions.
Adhere to community guidelines and comply with instructions given by moderators.
Rule 6: Use appropriate language and tone.
Communicate using suitable language and maintain a professional and respectful tone.
Rule 7: Report violations.
Report any violations of the community rules to the moderators for appropriate action.
Rule 8: Foster a continuous learning environment.
Encourage a continuous learning environment where members can share knowledge and engage in scientific discussions.
Rule 9: Source required for answers.
Provide credible sources for answers. Failure to include a source may result in the removal of the answer to ensure information reliability.
By adhering to these rules, we create a welcoming and informative environment where science-related questions receive accurate and credible answers. Thank you for your cooperation in making the Ask Science community a valuable resource for scientific knowledge.
We retain the discretion to modify the rules as we deem necessary.
