What are the preferred choices of materials in gas turbine j

What are the preferred choices of materials in gas turbine jet engines for the
following components:
(i) Fan blades (for a turbofan type engine), rotating at around 3,000 rpm
(ii) Turbine blades, rotating at around 10,000 rpm at a temperature up to
1400°C.
Explain the requirements from the material in order to operate at these extreme
conditions and any special treatments that the components may receive for this
purpose.

Solution

Fan blades operate in extreme temperature and weather conditions. The blades rotate at 3300 rpm and are subjected to high centripetal forces as high as 900 KN. Modern blades are made from titanium alloys such as Ti-6Al-4V. One method used for manufacturing fan blades uses two blade skins shaped from molten titanium in a hot press. Once shaped the blades are removed and welded to a mate, with a hollow cavity in the centre. This cavity is then filled with a titanium honeycomb structure for increased strength.

Turbine blades experience extreme conditions with speed as high as 10000 rpm along with huge centrifugal stress The operating temperature is around 1400⁰C and the material is prone for creep. The blades and discs are made from nickel based super alloys such as 54Ni22Cr12.5Co8.5Mo1.2Al and 55Ni22Cr5Co3Fe14W2Mo0.35Al0.10C0.015B. Each blade is also coated in an advanced ceramic material designed to shield them from the high temperatures produced.