Armor/Hull:
The standard armor scheme of UNSCN warships has been greatly improved since the Human-Covenant War, especially with the adoption of the Covenants own armoring and forging methods and technologies, along with advanced materials developed from the study of Forerunner and Archeohomina composites.
The standard internal superstructure of UNSCN ships is an 'airframe' made entirely out of durallium, a high entropy alloy composed of atomically 'blended' carbon, manganese, diamondoids, chromium, nickel, iron, titanium, coltan, molybdenum, and tungsten, supported by a series of tightly packed carbon nanotube structural support struts and shock-hardening liquid-bonded Octagon battleplate cross bracings that act as a sort of substructure, improving structural integrity and compartmentalizing much of the ships internals.
From here, the superstructure would serve the 'skeleton' of the ship from which the rest of the armor, hull and decking is built upon.
As for the armor itself, this was separated into layers by insulating polymer matrix composite cages of aerogel, nanocrystal, and high temperature resistant-thermal absorbing elastics, creating gaps in-between the armor plates that were filled with carbon nanotube weaving, actively cooled ablative liquid crystal, and encapsulated foam healing agents that could seal minor hull breaches automatically.
Going onto the rest of the armor layers, these were a metal matrix composite of titanium, zirconium, molybdenum, osmium, steel, tantalum, vanadium, carbon, and nanodiamond, using continuous carbon fibers as the reinforcing phases. This MMC was formed through layering the atomic structures of these materials, like the durallium, at specific orientations and thicknesses on the sub-Micron level, allowing them to be grown atom by atom using advanced nanomachine forges.
Named the Octagon Battleplate, this fully dense MMC formed the primary armor plating of UNSCN warships, having incredible toughness, structural strength, thermal properties and a quaint amount of corrosion resistance.
The outer armor itself was laminated with an EARN applicant. Made out of energy absorbent regenerative non-newtonian nanomaterials, this formed a superconducting layer that absorbed directed energy attacks and safely dispersed across a wider section of the hull, lowering chances of a breach. This allowed greatly better protection against heavy energy weapons without adding much mass or additional maintenance.
Finally, spread throughout each layer of the armor and the gaps were a network of micro-gravimetric emitters, creating localized gravitational fields that absorb the force generated by weapon impacts and redirects them away from the armor, diffusing the attacks.