Compressor Wheels (turbojet/turbofan)

Compressor stages are subjected to repetitive thermal transients ranging from ambient to elevated operational temperatures near 900°C, particularly in multi-stage axial designs adjacent to combustor zones. Materials are selected based on their phase stability, oxidation resistance, and γ′ precipitate strengthening mechanisms. Nickel-based superalloys such as Inconel 713C, MAR-M247, and René-series alloys are deployed, often with controlled solidification and directional grain structures. Heat treatment cycles are defined to optimize creep resistance, thermal fatigue life, and phase homogeneity under sustained thermomechanical loads. 

Compressor blade aerodynamics depend on maintaining boundary layer stability, minimizing flow separation, and reducing profile drag. Sub-optimal surface finishes, tooling marks, or micro-cracks induce turbulent flow, decreasing stage pressure ratio and isentropic efficiency. Surface treatments involve abrasive flow machining and micro-polishing to achieve surface roughness values below 0.2 µm Ra across both suction and pressure sides of the blade. Critical flow paths are evaluated using CFD-driven feedback loops to ensure compliance with designed Mach number distributions and incidence angle constraints.