Lot of discussion on Indian Defence forums surrounding the turbine development for the Light Combat Aircraft, after Aero India 2009.
Gas Turbine Research Establishment(GTRE)has got most of the thrust out of the Kaveri indigenous engine but one of the reasons holding them back from getting the last few100 newtons seems to be single crystal blade technology.
There are of course a few other factors, none of them in the least insurmountable. It seems that most efforts to develop a
jet engine fail at the last few hurdles, most are able to make it up to getting the basic chassis and thrust going even making an airframe and flying it with a GE or Rolls Royce engine.But increasing the thrust to provide enough afterburner thrust for the airframe or making the airframe light enough for the weaker engine all require high-end materials science. The Chinese for example have failed to produce a powerful engine so far. This last step of optimization and blade technology is so high tech that no one wants to share it.
Designing a jet engine from scratch isnt easy and all the powers which have one went through a significant development and design cycle plus had adequate funding.
GTRE has done well to get it so far.They were faced with sanctions, almost no external aid and simply thrown aside when it came to funding. But now they have got the Kaveri to the initial specifications of the IAF. But it seems the LCA airframe is quite heavy to allow it to perform as well with the Kaveri as with other engines.

I am glad that they are prepared to take help from Snecma to speed up things. Especially since the LCA has now completed 1000 sorties and deserves to finally have its Indian legs in place.

Today conventionally manufactured aircraft turbine blades are the norm and the high temperatures inside a turbine of a jet engine can start problems at crystal boundaries of such aerofoils. Especially stress and slippage under load to increased chemical activity can weaken them quickly.
So Pratt & Whitney set out in the early 1960s, to eliminate grain boundaries from turbine airfoils altogether, by inventing techniques to cast single-crystal turbine blades and vanes. Here is what a single crystal looks like:

Here is a single crystal blade..there are supposed to be no boundaries:
The beige single crystal blades on this GE 9H turbine
As I understood it...
manufacturing them isnt easy as expected(or China would have its own GE & Rolls Royce engine at 1/5th the price out in the black market by now) It involves solidifying the crystal from a special alloy solution gradually so the solidification front gradually advances from top to bottom and the solid part is gradually pulled out of the vessel.
Well Godspeed GTRE !