There are three aspects to SCB tech
- Material : Exotic superalloys that withstand extremely high temperature and maintain mechanical properties.
- Design: Cooling is absolutely necessary as the jet fuel burn at temperatures higher than the melting point of the super alloy.
- Manufacturing: Proper casting, forging, machining, quality checks, the whole shebang.
A shortcoming in either of these will lead to warping of turbine blades, or "throwing" them away. Kaveri program for a very long time ran on imported blades from Snecma.
GTRE came up with design requirements which were revised based on material technology by DMRL
DMRL came up with with material technology, made SCB for Kaveri prototypes as pilot project and transferred it's production standards and processes to HAL.
HAL received the capability to manufacture SCB from Russia for AL-31. Plant machinery, training for workers, quality checks at every stage of manufacturing, capabilities that do not come overnight. HAL also made a few production prototypes of Kaveri HPT's single crystal blade.
Currently our SCB technologies are very limited, we are both restricted by our material technology in superalloys and corresponding design restrictions due to which the engine is forced to operate at a lower temperature than what was originally intended. We haven't even come to mass production issues yet, hopefully the good experience gained by making AL-31 at decent quality will make producing Kaveri less painful than what it might otherwise have been.
Says the guy who believes that HAL imports single crystal blades under the garb of raw materials under some secret 'agreement' because ze Russians take all our
monnies and never give ze technologies to ze innocent Yindians and our DPSU and defence lab guys poop out solid single crystal gold bars.
You know it all don't you, let me frame your version of events because sooner or later you will lead the thread down that line:-
"Ze Russians never gave us SCB tech, itz our hard working guys at DMRL and GTRE that developed the SCB tech indigenously and gave it to the HAL so that they can produce the AL-31 locally. The domestic SCB is 20% cheaper, 40% lighter, 60% more awesome and boosts the SFC by 100%. Kaveri engine also has 1000 mm RHA equivalent of armour between the LP compressor and HPT. Here, look at a human head stuck on a pike by the aboriginal people of Andaman islands. I am going to use its eyeballs as reference to measure the size of crystals in this SCB blade."