Invar 36,Super Invar 32-5,UNS K93050,E FORU

### **Super Invar 32-5 / UNS K93050** **Ultra-Low Thermal Expansion Iron-Nickel-Cobalt Alloy for Extreme Precision Applications** --- #### **1. Overview** **Super Invar 32-5** is an advanced iron-nickel-cobalt alloy that exhibits an exceptionally low coefficient of thermal expansion (CTE), approximately one-third that of standard Invar 36. This enhanced property makes it ideal for applications requiring extreme dimensional stability over temperature variations. The alloy achieves its superior performance through precise control of nickel content and strategic cobalt additions, which optimize the temperature range for minimal thermal expansion around room temperature. --- #### **2. Chemical Composition (Weight %)** The typical chemical composition of Super Invar 32-5 is outlined below. The balance is Iron (Fe). | Element | Content (%) | Key Function | | :--- | :--- | :--- | | **Iron (Fe)** | Balance | Forms the primary matrix of the alloy. | | **Nickel (Ni)** | 31.5 - 32.5 | Primary element responsible for the ultra-low thermal expansion characteristics. | | **Cobalt (Co)** | 4.5 - 5.2 | Fine-tunes the thermal expansion properties and extends the low CTE temperature range. | | **Manganese (Mn)** | 0.20 - 0.40 | Enhances workability and acts as a deoxidizer during manufacturing. | | **Silicon (Si)** | 0.10 - 0.20 | Improves fluidity during processing while maintaining low expansion properties. | | **Carbon (C)** | 0.02 max | Kept at minimal levels to prevent aging effects and ensure long-term stability. | | **Chromium (Cr)** | 0.10 max | Controlled impurity. | | **Copper (Cu)** | 0.10 max | Controlled impurity. | | **Aluminum (Al)** | 0.05 max | Controlled to maintain consistent material properties. | | **Sulfur (S)** | 0.008 max | Minimized to prevent hot shortness and ensure purity. | | **Phosphorus (P)** | 0.008 max | Kept at trace levels to maintain ductility and stability. | --- #### **3. Physical Properties** | Property | Value / Condition | | :--- | :--- | | **Density** | 8.13 g/cm³ (0.294 lb/in³) | | **Melting Point** | ~ 1425 °C (2597 °F) | | **Mean Coefficient of Thermal Expansion** | 20 - 100°C (68 - 212°F): **0.5 x 10⁻⁶/°C** (0.28 x 10⁻⁶/°F)
20 - 200°C (68 - 392°F): **1.2 x 10⁻⁶/°C** (0.67 x 10⁻⁶/°F)
20 - 300°C (68 - 572°F): **2.0 x 10⁻⁶/°C** (1.11 x 10⁻⁶/°F) | | **Thermal Conductivity** | 10.7 W/m·K (74 Btu·in/hr·ft²·°F) at 20°C (68°F) | | **Specific Heat Capacity** | 515 J/kg·K (0.123 Btu/lb·°F) at 20°C (68°F) | | **Electrical Resistivity** | 0.79 μΩ·m at 20°C (68°F) | | **Modulus of Elasticity (Young's Modulus)** | 143 GPa (20.7 x 10⁶ psi) at 20°C (68°F) | | **Curie Temperature** | ~ 270 °C (518 °F) | | **Magnetic Properties** | Ferromagnetic below Curie temperature | --- #### **4. Mechanical Properties (Typical for Annealed Condition)** | Property | Value at Room Temperature | | :--- | :--- | | **Tensile Strength** | 480 MPa (70 ksi) | | **Yield Strength (0.2% Offset)** | 310 MPa (45 ksi) | | **Elongation (in 50 mm / 2 in)** | 32% | | **Reduction of Area** | 68% | | **Hardness (Rockwell B)** | 75 HRB | | **Vickers Hardness** | 155 HV | --- #### **5. International Standards** Super Invar 32-5 conforms to the following international specifications: * **ASTM:** * **F1684:** Standard Specification for Iron-Nickel and Iron-Nickel-Cobalt Alloys for Low Thermal Expansion Applications * **UNS:** K93050 * **ISO:** * **ISO 19960:** Iron-nickel low expansion alloys * **JIS:** * **JIS G 2311:** Iron-nickel thermal expansion alloys * **Aerospace Standards:** * Various manufacturer specifications for precision components --- #### **6. Product Applications** Super Invar 32-5 is essential in applications requiring the highest level of dimensional stability: * **Precision Aerospace Systems:** * Space telescope structural components * Satellite metrology frames * High-resolution imaging system mounts * Optical bench structures * **Scientific Instruments:** * Interferometer components * Laser measurement system frames * Atomic clock reference structures * Fundamental physics research equipment * **Semiconductor Manufacturing:** * Photolithography mask frames * Wafer stepper components * Precision measurement equipment * Clean room instrumentation * **Metrology and Calibration:** * Primary length standards * Ultra-precision gauge blocks * Calibration reference frames * Standards laboratory equipment * **Advanced Optical Systems:** * Telescope mirror supports * Optical delay lines * Laser gyroscope components * High-precision optical mounts --- #### **7. Key Characteristics & Advantages** * **Ultra-Low Thermal Expansion:** CTE as low as 0.5 x 10⁻⁶/°C, approximately one-third that of standard Invar 36 * **Exceptional Dimensional Stability:** Maintains precise dimensions under temperature variations * **Optimized Composition:** Cobalt addition extends the low CTE temperature range * **Superior Performance:** Outperforms standard Invar alloys in critical temperature ranges * **Good Mechanical Properties:** Balanced strength and ductility for precision applications * **Excellent Long-Term Stability:** Minimal aging effects for permanent installations * **Proven Reliability:** Trusted for the most demanding scientific and aerospace applications * **Manufacturing Versatility:** Can be machined and fabricated using specialized techniques --- **Disclaimer:** *The values provided are typical and for informational purposes only. For critical applications, always consult the official material data sheets from the supplier and relevant design codes. Super Invar requires specialized heat treatment and handling procedures to achieve optimal dimensional stability properties.*

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 1684 gallon liquid totes Special package is available on request.