Dr. M. Govindaraju,Dr. R. Vaira Vignesh & Dr. B. Venkataraman were funded by the AR&DB and DRDO

PI

Dr. M. Govindaraju
Associate Professor
Amrita School of Engineering, Coimbatore
m_govindaraju@cb.amrita.edu
+917207359461

Co-PH

Dr. R. Vaira Vignesh
Assistant Professor (Selection Grade) – Research Track
Department of Mechanical Engineering
Amrita School of Engineering, Coimbatore
r_vairavignesh@cb.amrita.edu
9944446208

Co-PI

Dr. B. Venkataraman
Distinguished Professor
Department of Mechanical Engineering
Amrita School of Engineering, Coimbatore
b_venkataraman@cb.amrita.edu
9866134453

The Funding Period is 31 May 2024 to 31 May 2027.

Outcomes

The outcomes of this project have significant applicability for missile systems and defense applications under DRDO’s Advanced Systems Laboratory. Specifically, the impact includes:

1. Enhanced performance of high-temperature joints in critical missile components by improving joint strength and reliability at temperatures up to 1400℃.
2. Increased lifespan and safety of defense systems by reducing thermal expansion mismatch between ceramics and metals.
3. Improved brazing techniques that can be scaled for the production of lightweight, high-strength components used in aerospace and defense sectors.

Project Focus

This project focuses on the development of advanced brazing techniques to join C(f)-SiC
composites with metallic parts, specifically Inconel alloy. The research will study joining advanced ceramics and composites to metallic parts, a critical challenge in the aerospace and defense industries.

Effective composite-to-metal bonding in high-temperature environments is critical for defense and aerospace systems, such as missile components and propulsion systems. The research addresses challenges associated with mismatched Coefficients of Thermal Expansion (CTE), intermetallic phase formation, thermal cycling stability, and long-term performance under operational conditions.

The project will develop optimized brazing joints using various braze alloys, coatings, and
interlayers to enhance joint strength, stability, and thermal endurance. It includes exploring
refractory metal-based interlayers (such as tantalum, molybdenum, tungsten, and niobium) and evaluating high-temperature performance up to 1400℃. A combination of thermal cycling tests, flame/arc exposure tests, and microstructural analyses will be conducted to ensure the joints meet stringent aerospace standards.

This research has significant scientific and practical importance, addressing several gaps in existing literature. The project will expand upon existing research by conducting component-level testing, thereby providing a comprehensive database of optimized brazing parameters for the sponsoring agency. The proposed methodology covers material selection, joint configuration, brazing cycle optimization, and performance evaluation at both the coupon and component levels. The project will create detailed guidelines for joint design, metallurgical characteristics, and performance parameters, providing the sponsoring agency with valuable insights for future aerospace applications.

The outcomes of this research will directly support Advanced System Laboratory, Hyderabad (Defence Research and Development Organization). By optimizing brazing parameters and conducting real-world application-oriented tests, the project aims to ensure reliable, high-performance ceramic-metal joints for critical defense applications.

Emerging areas where this work will contribute include:

1. Ceramic-metal joining technology for missile components
2. Advanced brazing methods for thermal and structural stability in extreme environments
3. Lightweight, heat-resistant composite structures for hypersonic vehicles and propulsion systems
4. Development of new brazing alloys and interlayer coatings for optimized joint performance

Impact in Other Areas

The brazing techniques and joint configurations developed in this project can be extended to other critical areas including:

1. Nuclear reactors – Graphite and ceramic-metal joints for nuclear applications.
2. Automotive sector – High-performance carbon-ceramic brake systems.
3. Gas turbines and jet engines – Thermal barrier coatings and high-temperature joints.
4. Medical field – Biocompatible ceramic-metal joints for implants and prosthetics.