DRDO develops single crystal blades for helicopter engine applications

New Delhi: Defense Research and Development Organization – DRDO has developed single crystal blade technology and has supplied 60 blades of these to Hindustan Aeronautics Limited – HAL as part of the indigenous helicopter development program for helicopter engine applications. It is part of a program initiated by DRDO’s premium laboratory Defense Metallurgical Research Laboratory (DMRL), in which five sets of single crystal high-pressure turbine (HPT) blades using a nickel-based noble composite metal (up to 300 in number) ) Are being developed. The supply of the remaining four sets will be completed in due time.

Helicopters used in strategic and defense applications require compact and powerful aero-engines for their reliable operation in extreme conditions. To achieve this objective, state-of-the-art single crystal blades with complex shapes and geometries, which are manufactured from nickel-based noble alloys capable of withstanding high temperatures of operation, are used. Very few countries of the world such as USA, UK, France and Russia have the capability to design and manufacture such single crystal (SX) parts.

DMRL had previously done this work on the basis of expertise gained during the development of such technology for the aero-engine project. The complete vacuum investment casting process to fabricate the blades, including dye design, wax pattering, ceramic molding, actual casting of parts non-destructive evaluation (NDE), heat treatment and dimensional measurement, has been installed at DMRL.

Special ceramic components had to be prepared to produce a strong ceramic mold, which can withstand the pressure of a liquid CMSX-4 alloy at temperatures of 1500 ° C and above during the casting operation. The challenge of maintaining the required temperature fluctuations has also been overcome by optimizing casting parameters. A multi-step vacuum solution heat treatment schedule has also been established for complex CMSX-4 noble alloys to achieve the necessary microstructure and mechanical properties. In addition, a rigorous non-destructive evaluation (NDE) method for blades as well as a technique for determining crystallographic orientations of these have been developed.

Defense Minister Rajnath Singh has congratulated DRDO, HAL and the industry involved in the development of critical technology.

Dr. G. Satish Reddy, Secretary, Research and Development in the Department of Defense, and Chairman of DRDO also congratulated the achievement and appreciated the efforts of the people involved in the indigenous development of this important technology.