Columbium material

In a significant stride towards self-reliance, the Indian Space Research Organisation (ISRO) has successfully developed an indigenous alternative to the imported Columbium material used in the nozzle divergent of the fourth stage of the PSLV (Polar Satellite Launch Vehicle).

• The new nozzle divergent is made of Stellite, a cobalt-based alloy comprising chromium, nickel, tungsten, and iron.
• Stellite has demonstrated excellent high-temperature strength retention, withstanding temperatures up to 1150°C. ISRO conducted a series of four hot tests—including a final successful test on April 8th, lasting 665 seconds—at its Propulsion Complex in Mahendragiri, Tamil Nadu. These tests confirmed the material’s suitability for operational deployment.
• The adoption of Stellite is expected to reduce costs by up to 90% compared to imported Columbium-based components. This innovation not only enhances cost-efficiency but also reduces dependence on foreign materials.
• In addition to the nozzle advancement, ISRO’s Mahendragiri facility has also successfully completed hot tests of the human-rated Vikas Engine, a critical component of the upcoming Gaganyaan human spaceflight mission.

About Columbium (Niobium)

• Columbium, now commonly known as Niobium, was discovered in 1801 by English chemist Charles Hatchett in an ore named columbite.
• Known for its strength, high melting point, chemical resistance, and low neutron absorption, niobium is widely used in the nuclear industry and has been the material of choice for early space power systems and rocket nozzles, particularly in its C-103 alloy form.