Nickel superalloys are selected for high-temperature gas turbine blades because of: a) High modulus. b) High creep strength. c) High maximum working temperature. d) b and c.

The correct option is : d) b and c.

Explanation:

A superalloy, also known as a high performance alloy, is a class of alloys that shows the following characteristics: high mechanical strength, surface stability, resistance to thermal creep and resistance to oxidation or corrosion at high temperatures.

Therefore, a nickel base superalloy is commonly used for the high temperature gas turbine blades because of high thermal creep strength and high maximum working temperature due to its stability at high temperatures.