Materials database

Weldable high-strength 7xxx aluminium — unique because most 7xxx alloys have poor weldability. Low Cu content gives better SCC resistance than 7075. Good mechanical property recovery after welding. Used for railway carriages, military bridges, mobile cranes, aircraft freight containers, and structural transport components.

Ultra-high-strength Al-Zn-Mg-Cu alloy — Zn 7.2-8.4%, higher than 7075 (5.1-6.1%). T73 temper: UTS 510-570 MPa with improved stress corrosion resistance over T6. Used for aircraft structural forgings (landing gear, wing spars), missile components, and high-strength fasteners. Developed for thick-section forgings where 7075-T6 SCC resistance is insufficient.

High-strength aerospace aluminium developed by Alcoa for thick-plate applications. Zr addition (instead of Cr) reduces quench sensitivity for superior properties in thick sections. T7451 temper gives excellent SCC resistance + fracture toughness. Used for fuselage frames, bulkheads, wing spars, and thick structural aerospace components.

The classic high-strength aerospace aluminium alloy. Al-Zn-Mg-Cu composition provides the highest strength of all common aluminium alloys in T6 temper. Poor weldability and limited corrosion resistance. Used for aircraft structures, M16 rifle receivers, rock climbing gear, and precision mold plates.

THE aerospace aluminum — Al-Zn5.6-Mg-Cu precipitation-hardened to the highest strength of any common aluminum alloy. T6 strength rivaling mild steel at 1/3 the density. Poor weldability and corrosion resistance vs 5xxx/6xxx. Used for aircraft wing skins, fuselage frames, high-stress structural components, and competitive cycling/climbing equipment. Often Alclad for corrosion protection.

High-purity damage-tolerant Al-Zn-Mg-Cu alloy — controlled Fe+Si (<0.22% total) for maximum fracture toughness. T7351: UTS 490-530 MPa with KIc ~33 MPa√m (vs ~26 for 7075-T6). THE alloy for fatigue-critical fuselage skins where crack growth rate matters most. Used for lower wing skins, fuselage skins of wide-body aircraft (Boeing 747/777), and any primary structure requiring damage tolerance.