Indian scientists repair aero-engine components using new cladding processes

Indian scientists have succeeded in repairing aero-engine components using newly developed laser cladding processes, the country’s Department of Science and Technology (DST) announced recently.

The scientists, from the DST’s International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), have been developing cladding processes for the repair of components made from nickel-based superalloys.

While these materials are widely used in aero-engine components, despite having exceptional properties they are prone to damage due to extreme operational conditions. In addition, manufacturing defects can occur during casting or machining, meaning tonnes of defective components have to be scrapped as a result.

As part of their work, the ARCI scientists indigenously developed powders suitable for additive manufacturing from unused scrap metal using an inert gas atomizer. These powders can then be used in cladding to refurbish defective parts.

In addition to aero-engine components the team is also able to refurbish pinion housing assemblies, critical components in helicopters used for power transmission to the main rotor. This is achieved by machining out any damaged layers and rebuilding them using laser cladding, followed by some final machining.

A post-clad heat treatment method has also been developed by the researchers in order to minimise microstructural inhomogeneity and ensure minimal substrate property variation.

The components repaired using the new processes were found to be free from distortion and exhibited excellent performance. The team is also able to repair and refurbish parts from other industrial sectors, such as diesel engine cylinder heads made of grey cast iron, and shafts used in refineries. Their work has been published in Transactions of The Indian Institute of Metals.