Turbocharger

Nozzle ring creep resistant nickel chrome alloy or moly chrome nickel steel or Nimonic alloy.
Turbine blades r nickel chrome alloy or Nimonic which has gud resistance to creep,fatigue and resistance.
Turbine casing is of cast iron
Compressor wheel is of aluminium alloy or titanium. Air casing is of Al alloy and in two parts.

Turbine blades are loosely fitted by fir tree method which gives positive fixing and min stress concentration at the conjunction of root and blade.
Root is slack fit to allow for differential expansion of root and blade and assists in damping vibr.
Binding wire or lacing wire is passed thru holes in the blades and damps the vibr due to friction btw the wire and blades. It can get damaged dur to fouling and corrosion and cracks can generate from the holes of binding wire also can be a problem.
Usually water cooled casings are necessary for turbo charger using come ball and roller bearings and integral Lube oil system.  Modern turbochargers with external lubricated journal bearings have uncooled casings
Adv
No thermal stresses
No chances of leaking
No hot Corr due to improper heating
No cold Corr due to excessive cooling
Greater overall