Single Crystal Alloy Gas Turbine Blade Heat Treatment Service Provider

Core Heat Treatment Processes for SX Turbine Blades

SX alloys are extremely sensitive to heat input. Our thermal treatment programs are specifically engineered to preserve crystal orientation and control phase transformation.

• Directional solidification stress relief at 1150–1180°C for 4–6 hours

• Aging treatment at 850–950°C for γ′ phase refinement and strength tuning

• Slow ramp rates (≤2°C/min) to prevent local recrystallization

• Vacuum and argon atmosphere to avoid oxide layer formation on hot section surfaces

All processes comply with NADCAP and OEM specifications for SX component treatment.

Common Single Crystal Alloys and Their Applications

These alloys are optimized for creep life, oxidation resistance, and directional solidification performance.

Case Study: Heat Treatment of CMSX-4 HPT Blade Set

Project Background

A client provided CMSX-4 turbine blades with critical crystal orientation and platform flatness requirements. We applied a two-stage thermal cycle: stabilization at 1160°C for 5 hours followed by double aging (871°C and 760°C). Microstructural analysis confirmed complete γ′ precipitation and no recrystallized grains.

Treated Components and Industry Applications

Each blade was evaluated for phase balance, γ′ size, and orientation preservation.

SX Blade Heat Treatment Challenges

1. Risk of recrystallization in thin-wall regions due to local overheating

2. γ′ phase control impacts creep resistance and service life

3. Differential cooling stress induces distortion if ramp rates are not uniform

4. Vacuum contamination can degrade surface oxidation resistance

5. Orientation shift or stray grains must be avoided during ramp-up

Technical Solutions for Thermal Processing of SX Blades

• Stabilization hold at 1150–1170°C to reduce internal stress from casting

• Primary aging at 871°C, secondary at 760°C to refine γ′ precipitate morphology

• Argon backfill in vacuum furnaces to limit oxidation and microstructural attack

• Quench rate control ≤10°C/min for platform flatness and dimensional preservation

• Post-process CMM inspection and SEM validation

Results and Verification

Execution of Heat Treatment

Furnaces operated under ±2°C control using multi-zone thermocouples. Time-temperature parameters were logged and matched to CMSX-4 and PWA 1484 process specifications. Components were visually inspected and cleaned post-cycle.

Metallurgical Results

γ′ volume fraction exceeded 60% in post-aging blades. No grain boundary coarsening observed. SEM analysis confirmed absence of recrystallized zones and stray grains.

Final Inspection

CMM verified platform distortion <0.02 mm. X-ray inspection validated internal integrity. SEM confirmed γ′ structure, carbide distribution, and clean grain boundaries.

FAQs

1. What temperature range is used for CMSX-4 blade heat treatment?

2. Can single crystal blades be aged without introducing stray grains?

3. What atmosphere is used for high-temperature SX alloy processing?

4. How do you ensure no recrystallization during treatment?

5. Do you offer HIP plus heat treatment for PWA 1484 blades?