Ti-8Al-1Mo-1V (Grade 20) Superalloy Casting Marine Turbine Blades Manufacturer
Introduction
Ti-8Al-1Mo-1V (Grade 20) is a near-alpha titanium alloy developed for high-temperature, corrosion-resistant applications requiring exceptional creep resistance and moderate strength. As an experienced superalloy casting manufacturer, we produce precision Ti-8Al-1Mo-1V turbine blades using vacuum investment casting, achieving ±0.05 mm dimensional accuracy and porosity under 1%.
These castings are ideal for marine turbine systems where components must endure long-term operation in hot, high-salinity environments while resisting oxidation, erosion, and distortion.
Core Technology: Vacuum Investment Casting of Ti-8Al-1Mo-1V
We use vacuum investment casting to produce Ti-8Al-1Mo-1V components with excellent surface finish, internal soundness, and oxidation control. The alloy is melted at ~1630°C and cast into 8–10 layer ceramic shell molds preheated to ~1000°C. Controlled solidification (cooling rate: 30–70°C/min) results in uniform equiaxed grain sizes (0.5–2 mm) with minimal shrinkage or alpha-case formation.
Material Characteristics of Ti-8Al-1Mo-1V (Grade 20)
Ti-8Al-1Mo-1V is a near-alpha alloy engineered for long-term use at elevated temperatures (up to 500°C), with good creep resistance, corrosion tolerance, and thermal stability. Key properties include:
Property | Value |
|---|---|
Density | 4.45 g/cm³ |
Ultimate Tensile Strength | ≥875 MPa |
Yield Strength | ≥820 MPa |
Elongation | ≥12% |
Creep Strength (1000h @ 500°C) | ≥160 MPa |
Operating Temperature Limit | Up to 500°C |
Corrosion Resistance | Excellent in marine environments |
These properties make Ti-8Al-1Mo-1V a suitable choice for turbine blades exposed to continuous salt spray, moisture, and elevated operating temperatures.
Case Study: Marine Turbine Blade Project
Project Background
A naval propulsion manufacturer required high-strength, heat-resistant turbine blades for a gas turbine-powered marine vessel. Ti-8Al-1Mo-1V was selected for its ability to resist oxidation and corrosion at elevated temperatures. We supplied vacuum-cast blades meeting MIL-STD material specifications, with HIP densification and CNC finishing for aerodynamic consistency and dimensional accuracy.
Typical Marine Turbine Blade Applications
High-Pressure Gas Turbine Blades (e.g., LM2500 Marine): Blades exposed to hot gas environments in shipboard propulsion modules where thermal creep and oxidation control are critical.
Intercooler Turbine Rotors: Lightweight, corrosion-resistant blades operating in moisture-laden exhaust zones within combined cycle marine gas systems.
Turbocharger Blades for Naval Engines: Fatigue-resistant castings designed for marine auxiliary gas turbines operating at variable rotational speeds.
Waterjet-Driven Microturbine Blades: Small, high-precision blades with optimized flow profiles for embedded propulsion systems in autonomous marine vehicles.
These blades provide structural integrity, weight efficiency, and long-term service life in harsh oceanic conditions.
Manufacturing Solutions for Marine Turbine Blades
Casting Process Wax patterns are assembled into ceramic shell molds. The alloy is vacuum cast at ~1630°C, with mold preheating at 1000°C to ensure full mold fill. Solidification is optimized to prevent shrinkage porosity and maintain fine-grain size across the airfoil.
Post-processing Hot Isostatic Pressing (HIP) is performed at 920°C and 100 MPa to eliminate microvoids and improve fatigue life. Solution aging follows to optimize microstructure and creep performance.
Post Machining Critical areas are finished using CNC machining to achieve aerodynamic contours and root interfaces. EDM is applied for tight tolerances and trailing edge details. Deep hole drilling creates coolant pathways and weight-reduction channels.
Surface Treatment Shot peening improves fatigue strength. Optional ceramic or aluminide coatings provide added oxidation resistance for extreme marine conditions. Surface passivation ensures long-term corrosion performance.
Testing and Inspection Each blade undergoes X-ray NDT, CMM inspection, and elevated-temperature mechanical testing. Metallographic analysis confirms proper grain structure, alpha-phase distribution, and oxidation layer thickness.
Core Manufacturing Challenges
Casting thin, high-aspect ratio airfoils without distortion or alpha-case formation.
Meeting ±0.05 mm tolerance for root, shroud, and leading-edge geometry.
Ensuring resistance to high-temperature oxidation and seawater corrosion over long durations.
Results and Verification
Dimensional accuracy within ±0.05 mm confirmed by 3D CMM.
Porosity <1% verified via X-ray and HIP analysis.
Mechanical strength ≥875 MPa and creep strength ≥160 MPa at 500°C.
Excellent corrosion resistance confirmed by ASTM G44 cyclic salt spray testing.
FAQs
Why is Ti-8Al-1Mo-1V (Grade 20) ideal for marine turbine blades?
What casting tolerances and surface finishes can you achieve?
How is alpha-case controlled during titanium casting?
Can your workshop customize turbine blades for specific propulsion designs?
What quality standards and inspection methods are applied to ensure marine compliance?
