Realization of High Pressure Turbine Blades of a Small Turbo-Fan Engine through Investment Casting Process

Abstract

Turbo-fan gas turbine engines, or simply turbo-fan engines (STFEs), are used for powering both manned aircrafts and unmanned air vehicles (UAVs). The high-pressure turbine section of such engines use Ni-base superalloy cast rotor blades because of their good mechanical properties at high operating temperatures. The present paper provides the technical/technological details of the various aspects associated with development and manufacturing of high-pressure turbine blades (HPTBs) for utilization in an indigenously developed small turbo-fan engine. Vacuum investment casting process has been adopted for realization of the above equiaxed components using a Ni-base superalloy.


Some of the cast parts: (a) blades and (b) test bars.
… 


dSC plot for casting material indicating temperatures corresponding to γ' dissolution (1176°C), incipient melting (1237°C), solidus (1279°C) and liquidus (1334°C).
… 


Laser CMM inspection results on a wax pattern injected using the manufactured die.(a) 3D best fit wax pattern and dimensional deviation values (in mm) in aerofoil section and corresponding 2d sections (b) AB; (c) AC and (d) Ad (see Fig. 3(a)). The magnified inset in Fig. 11(d) clearly shows the actual profile (in red) with respect to the tolerance band (in green) and nominal profile (in blue). The deviations at various locations are mentioned in boxes.
… 


Specified tolerance values for various features of the component. TE refers to 'trailing edge' of the HPT blade
… 

 

Description