The National Aerospace Laboratories has initiated research and development on Nickel–Titanium–Hafnium high temperature shape memory alloys. These alloys are designed to exhibit low thermal hysteresis, making them highly suitable for advanced actuation systems operating under elevated temperature conditions.

Two alloy compositions have been successfully prepared. The first is Ni50 Ti30 Hf20, and the second is Ni24 Ti30 Hf20 Cu6, both expressed in atomic percentages. These alloys were produced on a 450 gram scale batch using the vacuum process arc-melting technique, which ensures purity and uniformity in the alloy structure.

High temperature shape memory alloys are critical for aerospace and defence applications. Their ability to undergo reversible phase transformations under thermal cycling allows them to function as actuators in extreme environments, including jet engines, spacecraft mechanisms, and advanced turbine systems. 

The addition of hafnium enhances transformation temperatures, while copper improves ductility and reduces hysteresis, making these alloys more reliable for repeated use.

In parallel, substantial work has been undertaken on the creep behaviour of IN718 superalloy. This nickel-based alloy is widely used in aerospace due to its excellent strength and corrosion resistance at high temperatures.

The study focused on samples subjected to post-weld heat treatment, a process that restores microstructural integrity after welding and enhances mechanical performance.

The creep behaviour analysis is particularly relevant for the combustion chamber outer casing of gas turbine engines. This component experiences prolonged exposure to high thermal and mechanical stresses, making creep resistance a vital property.

By conducting detailed evaluations after post-weld heat treatment, NAL aims to ensure that IN718 can deliver extended service life and reliability in demanding operational conditions.

IN718 superalloy is already a cornerstone material in aerospace, nuclear, and energy sectors. Its application in turbine engines includes discs, casings, and blades, where resistance to creep, fatigue, and oxidation is essential.

The current research strengthens its role in India’s indigenous gas turbine development programs, reducing dependence on imported materials and enhancing self-reliance in strategic technologies.

These parallel initiatives highlight NAL’s commitment to advancing indigenous materials science for aerospace propulsion. The development of Ni-TiHf shape memory alloys opens pathways for innovative actuation systems, while the creep studies on IN718 superalloy ensure durability and safety in turbine engine casings.

Together, they represent a significant step in India’s efforts to build a robust domestic ecosystem for advanced aerospace materials.

Agencies