Thread by @vaimaniki

Tender from HAL for outsourcing of Single Crystal Blade castings for HPT and LPT. Interesting. My best guess is this is for Adour 871 engines which power IAF's Hawk AJT fleet.

Not the first tender from HAL related to Single Crystal Blades. There was one similar tender for SCB, which I suppose meant for HPT of HTSE-1200 few years back and then a follow up tender for TBC coatings for the same.

And interestingly, GTRE has floated tender for machining and TBC quoting for SC blades and vanes meant for HP Turbine early 2019. Which engine it is meant for exactly, is anyone's guess. Kaveri engine as of now is known to be using DS blades only.

Even more interestingly, GTRE is looking for 3D printed HPT Nozzle Guide Vanes out of In718 using DMLS technology.

In Single Crystal Blade technology, the investment casting of SC is one piece of puzzle. From stock casting to final blade needs two more critical technologies

1. Laser drilling for cooling holes 2. Thermal Barrier Coating (TBC). While DMRL has been making SCB castings for a decade now, we lacked these key technologies. But it looks like some steady progress is happening on TBC at least. DMRL indicated preliminary success in

Electron Beam Physical Vapour Deposition (EBPVD) based Yttrium Stabilized Zirconium 7YSZ coating in 2017 (this is the cutting edge tech). Now, in 2019 they are looking to estb a pilot facility for EBPVD based TBC application. ARCI also working in EBPVD and seems to have made good

progress. It is likely that ARCI was the one which did TBC for HAL's HTSE-1200 HPT blades and vanes. Whether DMRL is following separate path or its in collabaration with ARCI is not clear. But definitely steady progress on TBC technology. It seems multiple instances of tech dev

is happening in key technology areas like SCB, TBC, Composites and so on. Much is going on in the background, but real test is to productionise and operationalise the technologies. We can definitely develop all those "super-secret" technologies given proper push from the top.

Correction - HPT is for a TurboShaft engine which means most likely - HTSE-1200. The LPT blades are for TurboFan are definitely for Adour 871, as far as I can see.

TBC coatings*