>>12585386Counterpoint, titanium is common as fuck on Earth, and it's also got physical properties that make it much more desirable than almost any other metal for most applications (ie corrosion-proof bridges and boats, vehicle frames, drive shafts, the list goes on and on) BUT because it's energetically intensive and complex to produce from its native form, titanium is hardly used outside of specialized applications. Instead iron, a heavier metal with roughly equal strength and bad corrosion resistance outside of alloys makes up the second biggest fraction of gross building material mass produced on Earth annually (only beat by concrete itself).
On icy moons the same logic will apply to not just titanium but all metals. They will be rare. They will be energetically intensive to produce. They will be comparatively complex to produce. Therefore they will be expensive. Meanwhile, igneous rocks will make up the majority of rock in the icy crust, Igneous rock, particularly basalt, needs only to be melted and extruded through dies to produce strong fibers. These fibers can be spun and woven into blankets which, if mixed with liquid water and frozen, will produce a very strong and lightweight material that is completely fracture resistant and quite stiff when thick, yet flexible if thin. Its use will be limited to applications where it will not be exposed to temperatures approaching zero celsius, because water ice softens and weakens significantly before melting, but below negative 20 to 30 celsius water ice is very hard, and in fact at temperatures below -100 C it begins to approach the hardness of steel.
While still not as good as metals, it will clearly be good enough to be used even for certain types of vehicles, and definitely for most types of structure. Basically, water ice + fiber composites will take the place of concrete on icy moons, except it will also include all the applications we'd use concrete for if concrete also had high tensile strength.
