♦ ISRO has developed an alternative for the imported Columbium material used for the nozzle divergent in the fourth stage of the PSLV launch vehicle. It has indigenously developed the nozzle divergent made of Stellite. This alternate material is a cobalt-based alloy with additions of Chromium, Nickel, Tungsten and Iron. 

♦ The tests conducted on the Stellite made nozzle divergent has proved that it can retain strength at high temperatures up to 1150 degree Celsius.

♦ The test was conducted at the ISRO Propulsion Complex in Mahendragiri in Tamil Nadu. The use of Stellite nozzle divergent in PSLV will save ISRO 90 percent of the cost incurred on imported Columbium.