One of the most important indicators of any gas turbine unit is its service life and reliability. In many respects, it is the impeller blades that determine these indicators, as they are the most heavily loaded element. During the operation of the unit, the working blades are subjected to cyclic, dynamic and static loads. In addition, working in an aggressive environment, the blades are highly susceptible to corrosion. Also, due to constant temperature changes, high thermal stresses occur in the blades.

It is in connection with the above that the working blades have no analogues among the parts that are manufactured by casting.

The temperature at which the working blades are operated is 800-1250°C. Therefore, when operating at such high temperatures, the main deformations and failures occur due to insufficient heat strength of the metal.

Today, the main material from which impellers are made is nickel-based alloys. Such alloys have a complex structure and phase composition. It is the structure that determines the main properties – fatigue resistance, ductility, and heat resistance.

The main direction in which metallurgists are moving is to improve production technologies and, as a consequence, to increase fatigue resistance.

One of the areas of focus is casting blades with a single-crystal structure. With this technology, there are no material structure boundaries and, consequently, reliability and service life are increased.