New coatings lengthen life of cutting tools for jet-engine alloys by 60% to over 200%

Scientists at the International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Hyderabad, have found that the best protective coating for cutting tools depends on the alloy being machined, and that the right choice can greatly extend tool life.

ARCI is an autonomous research centre of the Department of Science and Technology. The work concerns nickel-based superalloys such as Inconel 718 (IN718), IN625 and IN617, used in aircraft engines, power plants and petrochemical systems. They are strong and hard, which makes them difficult to cut: they harden quickly, conduct heat poorly and react chemically with tools, so tools wear fast and costs rise.

What they tested

The team deposited two nanocomposite coatings, titanium aluminium silicon nitride (TiAlSiN) and chromium aluminium silicon nitride (CrAlSiN), on tungsten carbide tools using cathodic-arc physical vapour deposition. They then tested the tools in milling the three alloys.

The results

• IN718: TiAlSiN improved tool life by about 80% compared with an uncoated tool.
• IN625: TiAlSiN improved tool life by about 60%.
• IN617: CrAlSiN raised tool life by more than 200%.

"There is no single coating that performs best for every superalloy," the release says. The findings give a scientific basis for choosing a coating alloy by alloy.

Why tools fail

A major cause of damage was repeated adhesion of the workpiece material to the tool; when the stuck layer breaks away it pulls out tiny fragments and causes chipping. Chipping and progressive wear were the main failure modes. The coatings delayed this damage.

The release describes laboratory research and does not say when industry might adopt the coatings.

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Source: official release by the Ministry of Science & Technology, issued through the Press Information Bureau, Government of India (04 NOV 2026 5:21PM by PIB Delhi). Read the full official text: Advanced protective coatings to improve machining of critical superalloys can help aerospace, energy & petrochemical sectors.