Current aerospace trends have placed a premium on engine performance and fuel efficiency; and, since performance and fuel efficiency both increase as the gas temperature inside the engine increases - this has created a need for complex aerodynamic turbine airfoils that operate at higher service temperatures.
Hot section airfoils must be able to maintain their structural integrity in an environment of extreme temperatures and corrosive gases. Their manufacture requires the use of special super alloys that are resistant to high temperature, oxidation, corrosion, and stress levels. The complex shapes required of these components can be achieved only with advanced investment casting technology. The dimensional control must be precise.
Demand for such airfoils has led to two advances on the grain structure of airfoil castings: directionally solidified (DS) and single crystal casting. Both advances are attempts to increase the high-temperature threshold of airfoil applications by altering the grain structure of the metal. (Grain boundaries are the weak link in cast parts.)
DS blades and vanes are solidified in a way that essentially orients all grain boundaries in the alloy in a single direction. As a result of this longitudinal grain alignment, both ductility and resistance to thermal fatigue is improved. Thus enhancing component life for our customers.
Single crystal castings eliminate grain boundaries altogether, as parts are produced that consist of a single crystal. The current method employed to produce these castings requires the most stringent control of the solidification cycle and the entire investment casting process.
PCC Airfoils, a leading producer of these components, has developed highly automated casting furnaces and investment casting processes for the manufacture of blades and vanes. Significant process development at PCC Airfoils with ceramic cores, solidification technology, computer modeling and inspection methods assures our continued strength in this market. PCC Airfoils, LLC consists of multiple manufacturing sites in the United States, Mexico, and England.
