18Ni-7Co-2.9Mo-2.1Ti Maraging Steel

This is a precipitation-hardening maraging steel, a high-strength iron-nickel alloy strengthened by intermetallic phases (primarily Ni₃Mo and related compounds) rather than by carbon content, making it extremely tough and weldable despite its high strength. Used predominantly in aerospace and defense applications—particularly landing gear, missile casings, and structural components in spacecraft—where the combination of exceptional strength, fracture toughness, and low distortion during heat treatment is critical. Engineers select maraging steels when conventional high-strength steels would sacrifice ductility or introduce welding difficulties; this alloy's low carbon content virtually eliminates brittleness and allows field repairs without embrittlement concerns.