Mar-M247 Alloy

Mar-M247 is a precipitation-strengthened nickel-based cast superalloy developed for demanding high-temperature environments. Renowned for its exceptional creep resistance, thermal fatigue strength and oxidation resistance, it is extensively utilized in aerospace, industrial gas turbines and advanced power generation systems where structural reliability under extreme thermal stress is critical.

Designed specifically for high-temperature structural applications, Mar-M247 delivers excellent mechanical stability and long-term durability at service temperatures approaching 1100°C. Its carefully optimized alloy chemistry combines solid-solution strengthening with gamma-prime (γ') precipitation hardening, enabling superior resistance to creep deformation, thermal fatigue and mechanical wear during prolonged operation.

The alloy is widely employed in turbine blades, turbine wheels, combustion hardware and other hot-section components for aero-engines and industrial gas turbines. Featuring high tensile strength, excellent stress rupture life and reliable oxidation resistance, Mar-M247 maintains stable mechanical integrity throughout severe thermal cycles and high-load operating conditions.

The addition of cobalt, tungsten, tantalum and hafnium significantly enhances high-temperature strength and creep resistance, while chromium improves oxidation and hot-corrosion resistance. Carbon, boron and zirconium contribute to grain boundary strengthening, further improving fatigue life and structural stability under demanding operating conditions.

Nickel acts as the primary matrix element. Chromium improves oxidation resistance, cobalt and tungsten strengthen the alloy at elevated temperatures, while tantalum, titanium and aluminium promote strong gamma-prime precipitation hardening.

Chromium (Cr): 8.0-8.8

Cobalt (Co): 9-11

Molybdenum (Mo): 0.5-0.8

Tungsten (W): 9.5-10.5

Aluminium (Al): 5.3-5.7

Titanium (Ti): 0.9-1.2

Tantalum (Ta): 2.8-3.3

Hafnium (Hf): 1.2-1.6

Carbon (C): 0.13-0.17

Boron (B): 0.01-0.02

Zirconium (Zr): 0.03-0.08

Nickel (Ni): Balance

Mar-M247 exhibits outstanding high-temperature mechanical performance and structural stability. Its elevated melting range and strong elastic modulus enable reliable operation under severe thermal and mechanical loading conditions, while favorable thermal conductivity assists in dissipating heat efficiently within turbine environments.

The alloy’s microstructure contains a high volume fraction of gamma-prime (γ') precipitates uniformly distributed throughout the nickel matrix. These precipitates effectively impede dislocation movement, substantially enhancing creep strength, fatigue resistance and stress rupture life during long-term service.

Grain boundary strengthening elements such as hafnium, boron and zirconium further improve resistance to crack propagation and thermal fatigue. This makes Mar-M247 particularly suitable for cast turbine components operating under repeated thermal cycling and sustained high stress.

Excellent Creep Resistance

• Mar-M247 maintains outstanding creep strength at temperatures approaching 1100°C, making it highly suitable for turbine blades and rotating hot-section components exposed to continuous stress and elevated temperatures.

Superior Oxidation & Hot Corrosion Resistance

• Its chromium-rich chemistry provides excellent resistance to oxidation and corrosive combustion environments, ensuring prolonged component life under harsh operating conditions.

Exceptional Thermal Fatigue Performance

• The alloy performs reliably during repeated heating and cooling cycles, minimizing thermal cracking and preserving structural integrity in demanding turbine applications.

High Stress Rupture Strength

• Mar-M247 offers excellent long-term stress rupture life, significantly improving operational reliability and reducing maintenance intervals for aerospace and industrial turbine systems.

Outstanding Mechanical Strength

• Possessing high tensile and yield strength at elevated temperatures, the alloy withstands severe mechanical loading while maintaining dimensional stability and resistance to deformation.

Mar-M247 is primarily manufactured through precision vacuum investment casting, enabling the production of complex high-temperature components with excellent dimensional accuracy and metallurgical quality.

Directional solidification and equiaxed casting processes are commonly applied depending on service requirements. Directionally solidified Mar-M247 offers improved creep resistance and thermal fatigue properties for turbine blade applications.

Due to its high strength and work-hardening tendency, machining operations require rigid tooling, optimized cutting parameters and effective cooling methods. Carbide and ceramic cutting tools are commonly employed to achieve high machining efficiency and surface quality.

Heat treatment processes are critical for optimizing gamma-prime precipitation and achieving maximum mechanical performance. Proper solution treatment and aging significantly enhance creep strength and fatigue resistance.