Compressor Blade Requirements
Gas turbine compressor blades operate in a demanding environment combining high rotational speeds (creating centrifugal tensile stress in the blade), aerodynamic loading from the pressurized gas stream, vibratory excitation from upstream and downstream blade row interactions, foreign object damage (FOD) risk, and moderate temperatures that increase through the compressor stages. Inconel 718 is used in the higher-pressure (hotter) compressor stages where temperatures exceed the capability of titanium alloys (approximately 750°F) but remain below the range requiring dedicated turbine-section alloys.
Manufacturing Approach
CastAlloy produces Inconel 718 compressor blades through closed-die forging to develop the grain flow pattern that maximizes fatigue life, followed by multi-axis CNC machining to achieve the precise airfoil profiles, platform dimensions, and root form geometries required for proper seating in the compressor disc. Surface finishes on the airfoil directly impact aerodynamic efficiency, so we achieve finishes of 32 Ra microinches or better on airfoil surfaces. Root forms (fir-tree, dovetail) are machined to tolerances of plus or minus 0.001 inches or tighter to ensure proper load distribution.
Quality Assurance
Compressor blades undergo 100% fluorescent penetrant inspection for surface defects, dimensional verification of airfoil profile and root form on CMM, surface roughness verification, weight sorting to minimize rotor imbalance, and frequency testing to verify natural frequencies fall outside operating excitation ranges. We provide full AS9100-compatible documentation. Request a quote for compressor blade production.