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HAL gets DRDO-developed Single Crystal Blades for helicopter engines
New Delhi, April 27, 2021
The public sector Hindustan Aeronautics Limited (HAL) has received single-crystal blades for helicopter engines developed by the Defence Research and Development Organisation (DRDO).
The single-crystal blades technology was developed by DRDO which supplied 60 of these blades to HAL as part of their indigenous helicopter development programme for helicopter engine application.
It was part of a programme taken up by the Defence Metallurgical Research Laboratory (DMRL), a premium laboratory of DRDO, to develop five sets (300 in number) of the single-crystal high-pressure turbine (HPT) blades using a nickel-based superalloy. The supply of the remaining four seats will be completed in due course, the Defence Ministry said in a press release.
Helicopters used in strategic and defence applications need compact and powerful aero engines for their reliable operation in extreme conditions. To achieve this, state-of-the-art single-crystal blades with complex shape and geometry, manufactured out of Nickel-based superalloys capable of withstanding high temperatures of operation are used.
Very few countries in the world such as the USA, UK, France and Russia can design and manufacture such Single Crystal (SX) components.
The DMRL undertook this task based on its expertise gained during the development of such a technology for an aero-engine project earlier, the release said.
Complete vacuum investment casting process to realise the blades, including die design, wax pattering, ceramic moulding, the actual casting of components non-destructive evaluation (NDE), heat treatment and dimensional measurement, has been established at DMRL.
The special ceramic composition had to be formulated for making strong ceramic moulds that can withstand the metallostatic pressure of liquid CMSX-4 alloy at 1500°C and above during casting operation. The challenge of maintaining the required temperature gradient has also been overcome by optimising the casting parameters.
A multi-step vacuum solutionism heat treatment schedule for complex CMSX-4 superalloy to achieve the required microstructure and mechanical properties has also been established. Stringent non-destructive evaluation (NDE) methodology for the blades along with the technique for determining their crystallographic orientations has been developed.
Defence Minister Rajnath Singh congratulated the DRDO, HAL and the industry involved in the development of critical technology.
Secretary Department of Defence R&D and Chairman DRDO Dr G Satheesh Reddy appreciated the efforts involved in the indigenous development of this vital technology.