Aero engine practice for blade anchorage is with fir tree roots which would be much too fancy for this turbine.

The steam turbine alternative is with a round anchorage formed on the end of a short stalk, an easier alternative in this case. The blades should have a little radial freedom, ie not held rigidly, and kept in place with plates either side of the root to prevent them 'walking out' of the turbine disc.

Regards Brian

Mike, if you were able to mil slots around the disc, could you mill the blades themselves from the disc, and then either form them curved with a pair of dies fitted to a mole wrench / vise grip pliers or leave them straight as cut? This construction would eliminate blade to disc joints and any issues with dissimilar materials. Just food for thought.

If you make he blades separate and glue them in, even with pins, I would suggest a sturdy blast shield to stand behind during testing. Unintended high velocity spontaneous disassembly is likely. Compressed air turbines can rotate at spectacularly high rpm. I worked with dental drill air turbines in industry for a while. I know of which I speak.