Invar 36,Alloy 36 Strip,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 Strip (UNS K93600) - Product Introduction** #### **Overview** Invar 36, also known as Alloy 36 or UNS K93600, is a premier nickel-iron alloy engineered for an exceptionally low Coefficient of Thermal Expansion (CTE). The "Strip" form of this alloy refers to a thin, flat-rolled product, typically supplied in coiled form, with a thickness generally less than 6mm (0.25 inches). This form factor is essential for high-volume precision applications in electronics and instrumentation, where ultra-thin, dimensionally stable, and fabricable material is required. #### **Key Characteristics of Alloy 36 Strip** * **Ultra-Low Thermal Expansion:** Exhibits a CTE of approximately **1.6 x 10⁻⁶/°C** between 20°C and 100°C, ensuring minimal dimensional change with temperature fluctuations. * **Precision Gauge Control:** Manufactured to tight thickness and width tolerances, crucial for automated stamping and assembly processes. * **Excellent Surface Finish:** Available with various surface finishes (e.g., cold-rolled, annealed, pickled) to meet specific application needs, such as plating or welding. * **High Formability:** In the annealed condition, the strip can be readily stamped, blanked, and formed into intricate components. --- #### **1. Chemical Composition** The unique properties of Invar 36 are achieved through a tightly controlled chemical composition. | 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. The magnetic permeability decreases and transitions to paramagnetic (non-magnetic) above its Curie temperature of ~279°C (534°F). | --- #### **3. Typical Mechanical Properties (Annealed Strip)** *Properties can vary based on the exact temper and thickness of the strip.* | Property | Value | | :--- | :--- | | **Tensile Strength** | 450 - 550 MPa (65 - 80 ksi) | | **Yield Strength (0.2% Offset)** | 250 - 310 MPa (36 - 45 ksi) | | **Elongation (in 2")** | 30% min | | **Hardness (Rockwell B)** | 70 - 85 HRB | | **Modulus of Elasticity** | 141 GPa (20.5 x 10⁶ psi) | --- #### **4. Product Applications** Alloy 36 strip is the preferred material for high-volume, precision-component manufacturing, particularly in the electronics industry. * **Electronics & Semiconductor Packaging:** * **Lead Frames:** The primary application. Used in high-reliability semiconductors, CPUs, and ICs where thermal stability prevents stress on silicon dies and wire bonds. * **Metal Cans & Lids:** For hermetic packaging of microelectronic and MEMS devices. * **Interposer Sheets and Shields:** Providing stable platforms within electronic assemblies. * **Display Technology:** * **Shadow Masks:** Critical perforated components in the deposition process for OLED displays, where dimensional stability ensures perfect color alignment. * **Precision Instrumentation & Controls:** * **Bimetallic Thermostats:** Serves as the low-expansion arm in thermal control strips and discs. * **Precision Scales and Pendulums:** Used in high-accuracy measuring instruments. * **Watch and Clock Components:** For gears and springs where timing accuracy is critical. * **Cryogenic Equipment:** * **Seals and Spacers:** Manufactured from strip and used in LNG systems and scientific cryostats. --- #### **5. International Standards** Invar 36 Strip is covered by several key international standards that specify requirements for strip and foil products. | 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 strip products, **ASTM F1684** is the most critical ASTM standard, often supplied with additional customer-specific requirements for temper, surface finish, and dimensional tolerances.* --- #### **Conclusion** Invar 36 (Alloy 36) Strip, UNS K93600, is a specialized, high-value material that enables modern microelectronics and precision engineering. Its unique combination of ultra-low thermal expansion, excellent formability, and availability in precise, thin gauges makes it indispensable for manufacturing components where microscopic dimensional changes are unacceptable. Sourcing strip that conforms to stringent international standards is essential for ensuring performance and reliability in these demanding applications.

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 2398 gallon liquid totes Special package is available on request.