Precipitation Strengthened Nickel Alloys
Precipitation-hardened nickel alloys (also called age-hardened nickel alloys) are very high-performance materials at elevated temperatures (up to 700–800°C or higher), which can achieve exceptional strength, creep resistance, and long-term thermal stability through an age hardening process. This is achieved by adding elements such as aluminium (Al), titanium (Ti), and sometimes niobium (Nb) which form intermetallic precipitates of gamma prime or gamma double prime (e.g., γ′ or γ″ phases) that obstruct dislocation movement, thereby significantly strengthening the alloy especially in creep-dominated environments. Precipitation-hardened alloys offer much higher strength and better high-temperature mechanical properties than solid solution strengthened alloys, but typically require more complex heat treatments (e.g., through solution annealing followed by aging).
Goodwin have developed a precipitation hardened nickel alloy called alloy G130 which has enhanced creep performance over materials such as alloy 625 and 617, while maintaining excellent manufacturability in thick sections and heavy section through section mechanical performance. This material is included in the standard ASTM A494 as grade CY2Co with a UNS number of N07130.
