M247: A Nickel-Based Superalloy for High-Temperature Applications
M247 is a nickel-based superalloy renowned for its outstanding mechanical strength, creep resistance, and oxidation resistance at elevated temperatures. It is widely used in demanding applications such as gas turbines, aerospace engines, and industrial components.
Composition and Features of M247
Elemental Composition
| Element | Typical Percentage | Role and Contribution |
|---|---|---|
| Nickel (Ni) | ~60% | Provides the base for thermal stability and corrosion resistance. |
| Chromium (Cr) | ~8.0–10.0% | Enhances oxidation and corrosion resistance. |
| Cobalt (Co) | ~9.0–10.0% | Improves high-temperature strength. |
| Aluminum (Al) | ~5.0–6.0% | Contributes to oxidation resistance and γ' phase strengthening. |
| Titanium (Ti) | ~0.5–1.0% | Provides additional γ' phase strengthening. |
| Molybdenum (Mo) | ~0.5–1.0% | Enhances creep resistance. |
| Tantalum (Ta) | ~2.0–3.0% | Improves strength and oxidation resistance. |
| Carbon (C) | ~0.15–0.20% | Increases hardness and wear resistance. |
| Boron (B) | ~0.01–0.02% | Enhances grain boundary strength. |
Key Properties of M247
| Property | Value | Significance |
|---|---|---|
| Density | ~8.6 g/cm³ | High density supports strength and durability. |
| Melting Point | ~1370–1390°C | Suitable for high-temperature environments. |
| Oxidation Resistance | Excellent | Performs reliably in oxidative conditions. |
| Creep Resistance | Superior | Ensures long-term performance under stress. |
| Fatigue Resistance | High | Withstands cyclic thermal and mechanical loads. |
Applications of M247
| Application | Industry | Details |
|---|---|---|
| Gas Turbine Blades | Aerospace | Delivers exceptional thermal and mechanical stability. |
| Combustor Components | Power Generation | Withstands extreme heat and oxidative conditions. |
| Turbocharger Wheels | Automotive | Ensures durability under high-speed operations. |
| Industrial Valves | Energy | Resists wear and oxidation in high-temperature environments. |
Specifications and Standards of M247
| Specification | Details |
|---|---|
| Form | Castings, bars, and powder. |
| Heat Treatment | Solution and aging treatments enhance strength and stability. |
| Standards | Conforms to AMS, ASTM, and ISO standards. |
Advantages and Limitations of M247
| Advantages | Limitations |
|---|---|
| Exceptional mechanical and creep resistance. | High density increases component weight. |
| Superior oxidation resistance at high temperatures. | Requires advanced manufacturing processes. |
| Reliable performance under cyclic thermal stress. | Limited machinability due to hardness. |
Frequently Asked Questions (FAQs)
What is M247 commonly used for?
M247 is extensively used in gas turbines and aerospace engines for components exposed to extreme heat and stress.
Why is cobalt included in M247?
Cobalt enhances the alloy's high-temperature strength and stability.
How does M247 resist oxidation?
The combination of chromium and aluminum forms a protective oxide layer, preventing degradation.
Is M247 suitable for welding?
While weldable, it requires specialized techniques to maintain its mechanical properties.
What makes M247 ideal for gas turbines?
Its high creep resistance, thermal stability, and oxidation resistance ensure reliable performance in turbine environments.
Conclusion
M247 is a high-performance superalloy designed to meet the challenges of extreme environments. Its robust properties make it an essential material for aerospace, energy, and industrial applications, where reliability and durability are paramount.