Indian researchers perfect manufacture of additive used in aircraft engine repair

Indian scientists have for the first time repaired components of an aero-engine using additive manufacturing or a 3D printing technique called the Directed Energy Deposition (DED) process that can significantly reduce repair costs and overhaul time. They have developed indigenously powders suitable for the additive manufacturing process, an official statement said on Tuesday.

Nickel-based superalloys are widely used in aero-engine components. Despite having exceptional properties, they are prone to damage due to extreme operational conditions. Manufacturing defects during the casting or machining process are another major cause of rejection, and tonnes of such unused components are scrapped due to minor defects.

A team of scientists from the Hyderabad-based International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), an autonomous R&D Centre of the Department of Science and Technology, indigenously developed powders suitable for additive manufacturing using the inert gas atomiser available at the institute, by melting unused scrap material. Utilising this, ARCI is developing the Laser-DED process for the repair of aero-engine components made of Ni-based superalloy.

Further, the ARCI team has developed a technology to refurbish the pinion housing assembly (critical component in helicopters used for power transmission to the main fan) by machining out the damaged layer and rebuilding it using the laser cladding process, followed by final machining. Laser cladding and Laser-DED (both processes) are the same. In general, termaser cladding is used for two-dimensional deposition (surface coating), and termlaser-DED is used for the manufacture of three-dimensional parts. A patent has been filed for the same.

These laser-clad repaired prototypes were found to be free from distortion and exhibited excellent performance. The team has also developed repair and refurbishment technologies for other industrial sectors, such as refurbishing diesel engine cylinder heads made of grey cast iron and refurbishing shafts used in the refinery. This work has been published in the journal Transactions of The Indian Institute of Metals .

The technology developed by ARCI can be best realised in the aerospace sector due to the expensive materials used, manufacturing costs, and stringent quality checks, the statement said.

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