What is the outer hull of Enterprise (NCC-1701) supposed to be constructed from? Are the later vessels in the franchise made from the same material(s)? I'm hoping for a Gene R. answer, but if not, the next best example from the franchise would suffice.
Star Trek: The Next Generation: Technical Manual (Paperback) by Rick Sternbach, Michael Okuda indicate the hulls of Federation ships were a hollow structure reinforced with structural integrity force fields for faster than light travel and woven composite materials using duranium and tritanium/titanium alloys. This is the only publication I have which would have any level of canon reference.
The outer hull of NX-class starships were lined with duranium. (ENT: "The Xindi") - Memory Alpha
Tritanium will frequently reappear in Star Trek as a construction material for starship hulls. TOS Spock states that tritanium is 21.4 times as hard as diamonds.
Tritanium alloy was a widely-used construction material. The bulkheads of Enterprise were composed of tritanium. (ENT: "Dead Stop") In the 24th century, Federation starships, specifically Galaxy-class, Intrepid-class and Raven-type, also had tritanium bulkheads. (TNG: "Where Silence Has Lease"; VOY: "Year of Hell, Part II", "The Raven", "Repentance") - Memory Alpha
I seem to recall from blueprints back in the 60's that the ENTERPRISE hull was ferro-cement. . .an attainable product and workable in space. TOS had the ship built in orbit. . .