Invar 36,Alloy 36 Sheet,UNS K93600,E FORU

British Specs:，American Specs: ASTM F1684 MIL-S-16598 Tooling plate ASTM B388 Sheet & strip ASTM B753 K93050 Free-cut Invar，German Specs:WS 1.3912

### **Invar 36 / Alloy 36 Sheet (UNS K93600) - Product Introduction** #### **Overview** Invar 36, also known as Alloy 36, is a nickel-iron alloy celebrated for its uniquely low coefficient of thermal expansion (CTE) within a range of approximately -100°C to 300°C. The name "Invar" is derived from "invariable," signifying its exceptional dimensional stability under temperature fluctuations. The sheet form of this alloy is critical for applications requiring thin, stable, and fabricable components that resist thermal growth. #### **Key Characteristics of Alloy 36 Sheet** * **Exceptionally Low Thermal Expansion:** CTE is typically **1.6 x 10⁻⁶/°C** between 20°C and 100°C, making it virtually stable over this range. * **High Formability:** The sheet can be readily stamped, deep-drawn, and formed into complex shapes in the annealed condition. * **Good Weldability:** Can be welded using common techniques like TIG, MIG, and resistance welding. * **Work Hardening:** Like most nickel alloys, it work-hardens rapidly during forming, which may require intermediate annealing steps for severe deformations. --- #### **1. Chemical Composition** The precise balance of nickel and iron is responsible for the alloy's low expansion properties. | Element | Content (%) | | :--- | :--- | | **Nickel (Ni)** | 36.0% min | | **Iron (Fe)** | Balance | | **Carbon (C)** | 0.10% max | | **Manganese (Mn)** | 0.60% max | | **Silicon (Si)** | 0.40% max | | **Phosphorus (P)** | 0.025% max | | **Sulfur (S)** | 0.025% max | | **Cobalt (Co)** | 0.50% max | | **Chromium (Cr)** | 0.25% max | --- #### **2. Physical Properties** | Property | Value / Description | | :--- | :--- | | **Density** | 8.11 g/cm³ (0.293 lb/in³) | | **Melting Point** | ~1427°C (2600°F) | | **Thermal Expansion Coefficient (CTE)** | **1.6 x 10⁻⁶/°C** (20-100°C)
2.7 x 10⁻⁶/°C (20-300°C) | | **Thermal Conductivity** | 10.5 W/m·K (at 20°C) | | **Specific Heat** | 515 J/kg·K (at 20°C) | | **Magnetic Properties** | Ferromagnetic at room temperature. Becomes non-magnetic above its Curie temperature of ~279°C (534°F). | --- #### **3. Typical Mechanical Properties (Annealed Sheet)** *Properties are indicative and can vary with sheet thickness.* | Property | Value | | :--- | :--- | | **Tensile Strength** | 517 MPa (75 ksi) | | **Yield Strength (0.2% Offset)** | 276 MPa (40 ksi) | | **Elongation (in 2")** | 30% | | **Hardness (Rockwell B)** | 70 - 85 HRB | | **Modulus of Elasticity** | 141 GPa (20.5 x 10⁶ psi) | --- #### **4. Product Applications** Alloy 36 sheet is essential in industries where thin, dimensionally stable components are required. * **Electronics & Semiconductors:** * **Lead Frames:** For high-reliability semiconductor packages. * **Shadow Masks:** Critical components in the manufacturing of OLED displays to ensure color precision. * **RF/Microwave Packaging:** Housing and lids for sensitive components where hermeticity and stability are key. * **Aerospace & Defense:** * **Composite Molding Tools:** Sheets are formed into tools and mandrels for curing carbon-fiber composites. Its low CTE matches that of the composite, preventing part distortion during the high-temperature cure cycle. * **Laser and Optical Systems:** Mounts, bases, and structural frames for precision optical systems in satellites and aircraft. * **Energy Sector:** * **Seals and Spacers:** Used in power generation turbines and cryogenic equipment. * **LNG Applications:** Components within liquefied natural gas systems. * **Precision Instrumentation:** * **Bimetallic Strips:** The low-expansion element in thermostats and other thermal control devices. * **Scientific Instrument Frames:** Ensuring measurement accuracy by minimizing thermal drift. --- #### **5. International Standards** Invar 36 Sheet is covered by several international standards governing its chemical and mechanical properties. | Standard Body | Standard Designation | Title / Scope | | :--- | :--- | :--- | | **UNS** | **K93600** | Unified Numbering System | | **ASTM** | **ASTM F1684** | Standard Specification for Iron-Nickel and Cobalt-Nickel Alloy **Sheet, Strip, and Plate** | | **AMS** | **AMS 7725** | Alloy 36, Sheet, Strip, and Plate (Aerospace Material Specification) | | **EN / Euronorm** | **EN 1.3912 / Ni36** | Wrought Steel Products | | **DIN** | **DIN 1.3912 / Ni36** | German Institute for Standardization | | **JIS** | **JIS NCF 2 / NILO 36** | Japanese Industrial Standards | | **GB** | **GB 4J36** | Chinese National Standard | *Note: For sheet and strip products, **ASTM F1684** is the most commonly referenced ASTM standard.* --- #### **Conclusion** Invar 36 (Alloy 36) Sheet, UNS K93600, is a high-performance material solution for challenges posed by thermal expansion. Its availability in sheet form enables the design and manufacture of lightweight, complex, and highly stable components that are vital for the accuracy and longevity of advanced systems in aerospace, electronics, and precision engineering. Proper selection and fabrication according to the relevant international standards are crucial for optimal performance.

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 2397 gallon liquid totes Special package is available on request.