Question

A superalloy gas turbine component was originally designed to operate at temperatures up to 760 °C and exhibited a stress rupture life of 900 h under this operating condition. An updated design calls for a thermal barrier coating (TBC) to be added to the same component to allow engine operation under the same conditions, but with an increase in reliability. If an increase in rupture life to 1800 h is desired, what temperature differential between the inside and outside of the component must be achieved by the addition of the TBC? Also discuss various strengthening mechanisms for the creep resistant superalloys. What could be the effect of grain size and orientation on the creep properties of the alloy. What benefits could be obtained if a single crystal component is produced?