What other materials apart from conventional nickel and steel superalloys can be used as a first stage turbine blade material? Steel and nickel chromium alloys have been prominent and most used as turbine blade material although there are other materials such as tantalum carbides, tungsten and many more which I have no knowledge of. But these materials are not being used or even planned on being used in the near future why is that?
Do the cons of these materials beat the pros of the ni-cr superalloys?
Turbine blades must withstand high tensile stresses at their blade roots and be resistant to cyclic stresses from fluctuating fluid dynamic loads- all of this at very high temperatures, and over great numbers of thermal cycles. This argues in favor of metallic blades and against ceramics in this application, because they perform better against fracture in tension and fatigue crack propagation.