Chennai, Apr 18 (UNI) The Indian Space Research Organisation (ISRO) on Friday

said the fourth stage PSLV engine test with Stellite Nozzle Divergent (a cobalt based

alloy) was successful and it would help in saving 90 per cent of costs.

In an update, ISRO the liquid engines being flown in the fourth stage of PSLV (PS4)

use nozzle divergent made up of imported Columbium (C103) material.

An alternate material, Stellite (KC20WN), was proposed for the nozzle divergent

realization to achieve Atmanirbharatha along with associated cost savings.

Stellite is a cobalt based alloy with additions of Chromium, Nickel, Tungsten and

iron. It is a material which retains good strength at high temperatures up to 11500C

and hence becomes a suitable material for high temperature applications.

As part of the qualification programme, three hot tests were already completed on

two hardware in the first phase, it said.

"On April 08, 2025, the final test of the qualification programme was successfully

completed through a hot test for a long duration of 665 seconds at the test facility

in ISRO Propulsion Complex, Mahendragiri",ISRO said.

The use of this alloy has resulted in cost savings to the extent of 90 per cent,it said.

UNI GV 1800