Alloy 27，Glass sealing 27 Alloy ，,E FORU

British Specs:，American Specs:，German Specs:

### **Product Introduction: Alloy 27 / Glass Sealing 27 Alloy** **Premium Cobalt-Nickel-Iron Alloy for Reliable Glass-to-Metal Sealing Applications** **Alloy 27**, also known as **Glass Sealing 27 Alloy**, is a specialized cobalt-nickel-iron alloy specifically engineered for critical glass-to-metal sealing applications. This controlled expansion alloy is designed to match the thermal expansion characteristics of certain types of glass and ceramics, ensuring reliable, hermetic seals in electronic components, semiconductor devices, and precision instruments. With its excellent thermal compatibility and proven reliability, Alloy 27 has become the material of choice for applications where seal integrity is paramount under varying thermal conditions. --- #### **1. Chemical Composition (Weight %)** | Element | Content (%) | | :--- | :--- | | **Cobalt (Co)** | 26.5 - 27.5 | | **Nickel (Ni)** | 26.5 - 27.5 | | **Iron (Fe)** | Balance | | **Manganese (Mn)** | 0.50 max | | **Silicon (Si)** | 0.50 max | | **Carbon (C)** | 0.15 max | | **Chromium (Cr)** | 0.20 max | | **Aluminum (Al)** | 0.10 max | | **Copper (Cu)** | 0.20 max | | **Zirconium (Zr)** | 0.10 max | | **Sulfur (S)** | 0.015 max | | **Phosphorus (P)** | 0.015 max | * **Precision Chemistry:** The carefully balanced ratio of **Cobalt** and **Nickel** (approximately 27% each) provides the unique thermal expansion characteristics required for matched glass sealing applications. --- #### **2. Physical Properties** | Property | Value | | :--- | :--- | | **Density** | 0.290 lb/in³ (8.03 g/cm³) | | **Melting Point** | 1425-1450°C (2600-2640°F) | | **Specific Heat** | 0.105 Btu/lb-°F (440 J/kg-°K) | | **Thermal Conductivity** | 10.5 Btu-ft/hr-ft²-°F (18.1 W/m·K) | | **Mean Coefficient of Thermal Expansion** | 5.0-6.5 x 10⁻⁶/°C (20-450°C) | | **Modulus of Elasticity** | 20 x 10⁶ psi (138 GPa) | | **Electrical Resistivity** | 35.0 μΩ·cm at 20°C | | **Curie Temperature** | 430°C (806°F) | --- #### **3. Mechanical Properties** | Property | Annealed Condition | | :--- | :--- | | **Tensile Strength** | 75-95 ksi (517-655 MPa) | | **Yield Strength (0.2% Offset)** | 45-65 ksi (310-448 MPa) | | **Elongation** | 30-40% | | **Hardness** | Rb 75-85 | | **Shear Modulus** | 7.5 x 10⁶ psi (51.7 GPa) | --- #### **4. Product Applications** **Primary Applications in Glass-to-Metal Sealing:** * **Electronics & Semiconductor:** - Transistor and IC package headers - Diode and rectifier packages - Microwave tube components - Ceramic-to-metal seal applications * **Aerospace & Defense:** - Hermetic connectors and feedthroughs - Sensor packaging - Laser tube components - Navigation system components * **Medical Devices:** - Pacemaker and implantable device enclosures - Medical sensor packaging - Diagnostic equipment components * **Industrial Applications:** - High-reliability electrical connectors - Power semiconductor packages - Optical device packaging - Vacuum tube components **Key Performance Characteristics:** - Excellent thermal expansion match with borosilicate glasses - Good wetting characteristics with sealing glasses - High strength and durability in sealed assemblies - Good oxidation resistance at sealing temperatures - Reliable hermetic seal formation --- #### **5. International Standards & Specifications** **Material Standards:** - **ASTM F15:** Standard Specification for Iron-Nickel-Cobalt Sealing Alloys - **UNS:** **K94610** - **MIL-DTL-23488:** Military specification for glass-to-metal sealing alloys - **ISO 13123:** Metallic materials — Method of test for the thermal expansion characteristics - **JIS C2531:** Japanese Industrial Standard for iron-nickel-cobalt sealing alloys - **GB/T 15013:** Chinese National Standard for glass-to-metal sealing alloys **Product Specifications:** - **Wire Diameters:** 0.005" to 0.250" (0.127mm to 6.35mm) - **Strip/Sheet Thickness:** 0.001" to 0.125" (0.025mm to 3.175mm) - **Rod Sizes:** 0.125" to 2.000" (3.175mm to 50.8mm) - **Surface Finish:** Bright annealed, pickled, or special finishes --- #### **6. Glass Sealing Performance** **Compatible Glass Types:** - **Borosilicate Glasses** (Corning 7052, 7040, etc.) - **Aluminosilicate Glasses** - **Special Sealing Glasses** with matched expansion characteristics **Sealing Process Parameters:** - **Sealing Temperature:** 800-1000°C (1470-1830°F) - **Atmosphere:** Hydrogen, vacuum, or inert gas - **Surface Preparation:** Critical for successful sealing - **Oxidation Control:** Essential for proper glass wetting --- #### **Why Choose Our Alloy 27 Products?** * **Precision Manufacturing:** Strict control of chemical composition and processing parameters * **Consistent Performance:** Reliable thermal expansion characteristics batch-to-batch * **Quality Assurance:** Comprehensive testing including thermal expansion analysis * **Technical Expertise:** Deep understanding of glass-to-metal sealing requirements * **Global Compliance:** Meets international standards and customer specifications * **Proven Reliability:** Extensive track record in critical sealing applications **Contact our technical team** to discuss your specific glass sealing requirements. We provide comprehensive solutions and technical support for your most demanding hermetic sealing applications, from material selection to processing recommendations.

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 2742 gallon liquid totes Special package is available on request.