INCONEL Alloy MA 754,Nickel-Chromium Alloy; UNS N07754，1

### **Product Introduction: INCONEL® Alloy MA 754 (UNS N07754)** **INCONEL® Alloy MA 754** is a unique **nickel-chromium-based oxide dispersion strengthened (ODS)** superalloy. Unlike conventional superalloys that are strengthened by precipitation hardening or solid solutioning, MA 754 derives its exceptional high-temperature strength from a uniform dispersion of fine, stable yttrium oxide (Y₂O₃) particles throughout the matrix. This is achieved through a specialized **Mechanical Alloying (MA)** powder metallurgy process. This structure provides an outstanding combination of very high tensile and creep-rupture strength, exceptional resistance to high-temperature oxidation, and excellent fatigue properties. It is specifically designed for long-term service in highly stressed applications at temperatures ranging from 1000°C to 1300°C (1800°F to 2400°F), where conventional alloys would soften and fail. --- ### **International Standards & Material Equivalents** This specialized alloy is primarily defined by aerospace and general material standards. | Standard Type | Standard Number | Designation / Product Form | | :--- | :--- | :--- | | **UNS (USA)** | **N07754** | **INCONEL Alloy MA 754** | | **AMS (Aerospace)** | **AMS 5892** | Bar and Wire (Solution Heat Treated and Recrystallized) | | **ASTM** | B849 | Bar | | **Proprietary** | - | Often supplied to manufacturer's own stringent specifications. | > **Note:** INCONEL® is a registered trademark of Special Metals Corporation. The key identifier is **UNS N07754**. The "MA" prefix explicitly denotes its **Mechanical Alloying** manufacturing process. --- ### **Chemical Composition** The composition provides a corrosion-resistant nickel-chromium matrix, while the yttrium oxide is the key to its dispersion strengthening. | Element | Content (%) | | :--- | :--- | | **Nickel (Ni)** | 78.0 min. | | **Chromium (Cr)** | 18.0 - 23.0 | | **Iron (Fe)** | 1.0 max. | | **Yttrium Oxide (Y₂O₃)** | 0.3 - 0.7 | | **Aluminum (Al)** | 0.3 max. | | **Titanium (Ti)** | 0.5 max. | | **Carbon (C)** | 0.05 max. | | **Silicon (Si)** | 0.5 max. | | **Manganese (Mn)** | 0.5 max. | | **Tungsten (W)** | 0.5 max. | | **Molybdenum (Mo)** | 0.5 max. | --- ### **Physical Properties** The physical properties reflect its high-temperature capability. | Property | Value | | :--- | :--- | | **Density** | 8.31 g/cm³ (0.300 lb/in³) | | **Melting Point** | ~1375 °C (~2500 °F) | | **Thermal Conductivity** | 14.5 W/m·K (at 20°C) | | **Electrical Resistivity** | 1.25 μΩ·m (at 20°C) | | **Modulus of Elasticity** | 217 GPa (31.5 x 10⁶ psi) | | **Coefficient of Thermal Expansion** | 14.5 μm/m·°C (20-1000°C) | | **Magnetic Response** | Essentially non-magnetic | --- ### **Mechanical Properties (Typical for Recrystallized Condition - AMS 5892)** The alloy exhibits remarkable strength retention at temperatures where other alloys soften drastically. | Property | Value (Room Temperature) | Value (at 1093°C / 2000°F) | | :--- | :--- | :--- | | **Tensile Strength** | 965 MPa (140 ksi) | 83 MPa (12 ksi) | | **Yield Strength (0.2% Offset)** | 690 MPa (100 ksi) | 69 MPa (10 ksi) | | **Elongation** | 15% | 25% | | **Hardness** | 28 HRC | - | --- ### **Key Characteristics & Advantages** 1. **Exceptional High-Temperature Strength and Creep Resistance:** The stable yttria particles inhibit dislocation motion and grain boundary sliding at temperatures up to 85% of its melting point, providing superior creep rupture life compared to conventional superalloys. 2. **Outstanding Oxidation Resistance:** The high chromium content forms a protective, adherent chromium oxide (Cr₂O₃) scale, providing excellent resistance to oxidation and scaling in air and other oxidizing atmospheres. 3. **Controlled, Coarse Grain Structure:** The final product is processed to have a coarse, elongated grain structure, which is optimal for high-temperature creep and stress-rupture properties. 4. **Excellent Thermal Fatigue Resistance:** Withstands repeated heating and cooling cycles better than conventional cast or wrought alloys due to its high strength and microstructural stability. 5. **Key Limitation:** **It is not weldable** by conventional fusion welding techniques. The intense heat destroys the controlled coarse grain structure and the uniform yttria dispersion, leading to severe loss of properties in the heat-affected zone. Joining is typically limited to mechanical fastening or specialized diffusion bonding. --- ### **Product Applications** INCONEL Alloy MA 754 is specified for the most demanding static, high-temperature components. * **Aerospace & Jet Engines:** * **Turbine vane segments and rings.** * **Afterburner components,** such as seal supports and spray bars. * **Blade shrouds** and other hot-section static structures. * **Industrial Gas Turbines:** * **Stationary vane components.** * Combustion chamber liners and support elements. * **Nuclear Industry:** * Core component support pins and other fixtures in advanced reactor designs. * **Heat Treating Industry:** * **Furnace fixtures,** radiant tubes, and trays for high-temperature sintering and heat treatment. ### **Summary** **INCONEL Alloy MA 754 (UNS N07754)** is a specialized **oxide dispersion strengthened (ODS)** superalloy that represents the pinnacle of high-temperature materials technology for static applications. Its unique **yttria-strengthened microstructure**, created via mechanical alloying, provides unparalleled **creep strength and oxidation resistance at temperatures above 1000°C**. While its **inability to be welded** limits its application, it remains an irreplaceable material for critical, highly-stressed components in the hottest sections of jet engines, industrial turbines, and high-temperature industrial furnaces, where no other material can offer comparable long-term performance and stability.

Packing of Standard Packing: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 3305 gallon liquid totes Special package is available on request.