I know we are already developing. Issue when we will have commercial ready engines ?
Do you know what is our issue? We want everything at the click of finger.
Turbine blades are 'One of the important aspect' of an engine, not 'The only aspect'.
Russia is making engines for so long. But are those commercially viable? By making a SCB or DSCB you can't claim that you are going to make a commercial ready engine.
For example, if today we built a stable 50 kn engine and want to built a 90 kn thrust one, what would be the way forward?
The Russian way is to increase the number of spools. We could go on and do the same. But the down side would be increase in weight. The same happened with Kaveri. So making a crystal blade is not enough. We have to study and design the spool itself to increase the pressure. There comes the spool design along with crystal blade technology.
But increasing the pressure on spool means increasing the vibration on shaft. So along with spool designing we have to work on shaft designing.
These are the issues we faced with Kaveri. There are multiple facet of a commercially viable engine to be taken care of even before making a prototype.