Mondaloy is a specialized nickel-based superalloy created in the mid-1990s by metallurgists Monica Jacinto Reza and Dallis Hardwick at Rocketdyne. It was engineered to solve a major aerospace challenge: resisting high-pressure, high-temperature gaseous oxygen environments without burning or requiring heavy protective coatings.

Nickel content: Comprises roughly 55–75% nickel by weight.

Alloying elements: Includes cobalt, chromium, aluminum, and titanium.

Burn resistance: Withstands oxygen-rich staged combustion (ORSC) without structural failure.

No coatings needed: Eliminates the fragile, crack-prone protective coatings used on conventional metals.

Key Uses: AR1 Engine: Used in about 12 components such as preburners, turbine rotors, and manifolds exposed to hot gaseous oxygen. Hydrocarbon Boost Technology Demonstrator: Tested by the U.S. Air Force Research Laboratory for reusable rocket engine architectures.