Inconel 718 Superalloy Equiaxed Grain Casting Compressor Turbine Vane Manufacturer
Introduction
Compressor turbine vanes operate in harsh thermal and mechanical environments, where resistance to fatigue, oxidation, and creep is critical. These static components must retain dimensional accuracy and mechanical integrity under high-cycle fatigue and elevated temperatures. Inconel 718, a precipitation-hardened nickel-chromium superalloy, is ideal for compressor turbine vanes thanks to its excellent tensile strength, corrosion resistance, and long-term thermal stability.
Neway AeroTech is a specialized manufacturer of Inconel 718 compressor vanes using equiaxed grain casting under vacuum investment casting conditions. Our casting and CNC machining services are optimized for aerospace, power generation, and marine gas turbine platforms.
Core Technology of Equiaxed Casting for Inconel 718 Turbine Vanes
Wax Pattern Production Airfoil and platform geometries are replicated via high-precision wax injection molding with ±0.05 mm dimensional tolerance.
Ceramic Shell Mold Construction 6–8 mm thick refractory shell molds are built using stucco and slurry coatings to ensure casting strength and dimensional accuracy.
Vacuum Induction Melting Inconel 718 is melted at ~1380°C under vacuum (≤10⁻³ Pa) for excellent chemical homogeneity and gas purity.
Equiaxed Grain Solidification Molten alloy is poured into preheated molds and solidified with uniform thermal gradients to produce equiaxed grain structures (ASTM 5–7).
Shell Removal and Cleaning Shells are removed by mechanical blasting and leaching to maintain airfoil edge quality and surface finish.
Heat Treatment Solution and aging treatment is performed to precipitate γ′ and γ″ phases for high creep and fatigue strength.
CNC Finishing and EDM Critical faces, bolt holes, and cooling slots are completed via CNC machining and EDM.
Inspection and Testing Dimensional inspection, X-ray NDT, and ultrasonic testing confirm part quality and process conformance.
Inconel 718 Material Properties for Turbine Vanes
Max Operating Temperature: ~700°C
Tensile Strength: ≥1240 MPa
Yield Strength: ≥1030 MPa
Creep Rupture Strength: ≥180 MPa at 650°C (1000 hours)
Corrosion Resistance: Excellent in combustion and marine environments
Grain Size: ASTM 5–7 (equiaxed)
Phase Stability: Strong γ′/γ″ response after aging
Case Study: Inconel 718 Vanes for Compressor Section of Aero-Derivative Turbine
Project Background
Neway AeroTech was contracted to supply equiaxed Inconel 718 vanes for a 40 MW aero-derivative gas turbine. The vanes were installed in the rear compressor stages and subjected to continuous high-pressure air, temperatures near 650°C, and aerodynamic vibration. Client specifications required tight dimensional tolerances, no porosity, and reliable creep performance over extended service cycles.
Applications
Rear-Stage Compressor Vanes: Operate under elevated pressure and temperature, requiring fatigue resistance and dimensional stability.
Transition Duct Vanes: Guide airflow from compressor to combustor, experiencing moderate thermal gradients and vibration.
Marine Turbine Static Blades: Used in salt-laden environments where corrosion resistance and weldability are essential.
Industrial Gas Turbine Compressor Stators: Support high-load startup and shutdown cycles under heavy-duty service schedules.
Manufacturing Process for Inconel 718 Compressor Vanes
CFD-Assisted Mold Design CFD modeling ensures proper gating and flow paths to avoid porosity, shrinkage, and segregation.
Vacuum Investment Casting Execution Inconel 718 is cast into ceramic molds under vacuum and controlled cooling conditions for equiaxed microstructure.
Post-Casting Heat Treatment Solution and aging cycles ensure optimal precipitation of strengthening phases (γ′ and γ″) and relieve residual stress.
Precision Machining Surfaces, holes, and platform faces are completed using CNC and EDM to meet final tolerances.
Final Inspection and Testing Dimensional inspection via CMM, and X-ray and ultrasonic NDT ensure full compliance with aerospace-grade standards.
Key Manufacturing Challenges
Preventing hot cracking in thin trailing edges
Controlling dimensional accuracy during solidification and machining
Achieving uniform γ′/γ″ phase precipitation after heat treatment
Ensuring weld repair compatibility if required in the field
Results and Verification
Grain size ASTM 6 maintained across blade cross-sections
Tensile strength verified >1240 MPa at room temperature
Final dimensional tolerances within ±0.03 mm
Creep and fatigue performance exceeded client thresholds
100% NDT pass rate for all production batches
FAQs
What makes Inconel 718 ideal for compressor turbine vanes?
How does equiaxed casting improve vane durability?
Can Inconel 718 cast vanes be welded or repaired?
What are typical tolerances for CNC-finished vane platforms?
What non-destructive testing is used for vane certification?
