Alloy 49, also known as Invar 49, is a nickel-iron alloy characterized by its low coefficient of thermal expansion. While its expansion rate is slightly higher than Alloy 48, it is still highly suitable for precision applications where minimal thermal distortion is crucial. Alloy 49 is recognized under various designations, including NILO 49, UNS K94890, DIN 1.3912, and A49. These designations indicate its adherence to international standards and specifications.

The alloy is composed of approximately 49% nickel and the remainder is iron. This composition results in very low thermal expansion, making Alloy 49 ideal for environments where precise dimensional stability is required despite changes in temperature.

Alloy 49 Sheet | Plate

Alloy 49 sheets and plates are available in a range of thicknesses and sizes, designed to offer exceptional dimensional stability and flatness. These products are used in high-precision applications such as aerospace engineering, advanced manufacturing, and high-tech instrumentation, where exact dimensions are critical for performance.

Alloy 49 Round Bar | Rod

Alloy 49 round bars and rods come in various diameters and lengths, suitable for machining into specific parts. These components are essential for applications requiring high accuracy and minimal thermal expansion, such as precision mechanical assemblies and structural components used in demanding environments.

Alloy 49 Strip | Coil

Available in strips and coils, Alloy 49 is utilized in applications requiring flexibility and continuous material. These forms are valuable in the manufacture of components like springs, connectors, and precision instruments where both flexibility and low thermal expansion are necessary. They are commonly used in sectors like automotive, electronics, and precision engineering.

Alloy 49 Applications

• Alloy 49 is used in research equipment and devices where maintaining exact measurements and stability across varying temperatures is essential for experimental accuracy.

Alloy 49 Properties

• Coefficient of Thermal Expansion: Approximately 1.2 x 10^-6 /°C, making Alloy 49 well-suited for applications requiring low thermal expansion with high precision.
• Density: About 8.2 g/cm³, which balances strength and weight, making it suitable for a variety of industrial uses.
• Thermal Conductivity: Approximately 14-16 W/m·K, offering moderate heat conductivity while ensuring dimensional stability.
• Magnetic Properties: Alloy 49 is generally ferromagnetic, which may be advantageous or require careful management depending on the application’s need for magnetic properties.
• Mechanical Properties: Alloy 49 combines good mechanical strength and ductility, designed for dimensional stability rather than maximum mechanical strength.

Machining Alloy 49

• Cutting: Alloy 49 can be cut using standard tools. Employ sharp tools and adjust cutting speeds to minimize tool wear and achieve smooth cuts.
• Drilling: High-speed steel (HSS) drills or carbide-tipped bits are recommended for drilling Alloy 49. Proper lubrication and cooling are crucial to extend tool life and ensure accurate holes.
• Turning: Carbide inserts are preferred for turning Alloy 49. Consistent feed rates and effective heat management are essential to maintain dimensional accuracy during turning operations.
• Milling: Alloy 49 can be milled using conventional methods. Utilize carbide end mills and cooling fluids to manage heat and avoid dimensional changes during the milling process.
• Grinding: Grinding Alloy 49 can achieve tight tolerances and fine finishes. Use appropriate abrasive wheels and coolant to ensure a high-quality surface finish while maintaining dimensional stability.

Chemical Composition

• Carbon (C): Max 0.035%
• Manganese (Mn): Max 0.8%
• Silicon (Si): Max 0.5%
• Phosphorus (P): Max 0.02%
• Sulfur (S): Max 0.008%
• Nickel (Ni): Min 47%, Max 50%
• Iron (Fe): Balance