Alloy 48,Nilo 48 Rod,UNS K94800,E FORU

British Specs:，American Specs: ASTM F30，German Specs:

### **Alloy 48 (Nilo 48) - Rod Product Overview** **Alloy 48**, commercially known as **Nilo 48**, is a controlled expansion iron-nickel alloy specifically engineered for matched sealing with hard glasses such as borosilicate and alumina-silicate types. The **Rod** form provides solid, cylindrical stock material for machining precision components that require excellent thermal expansion compatibility with hard glass. * **UNS Designation:** **K94800** * **Common Names:** Nilo 48 Rod, Glass Sealing 48 Rod --- #### **1. Chemical Composition** Precisely controlled chemistry ensures consistent thermal expansion properties in rod form. | Element | Percentage (%) | Role in the Alloy | |:---|:---|:---| | **Nickel (Ni)** | 47.5 - 48.5 | Controls CTE characteristics and Curie point | | **Iron (Fe)** | Balance | Base structural element | | **Manganese (Mn)** | 0.10 - 0.30 | Enhances hot workability during rod production | | **Silicon (Si)** | 0.10 - 0.30 | Improves glass wetting characteristics | | **Carbon (C)** | 0.05 max | Limited to prevent embrittlement | | **Sulfur (S)** | 0.02 max | Controlled impurity | | **Phosphorus (P)** | 0.02 max | Controlled impurity | --- #### **2. Physical Properties** Specialized properties optimized for rod applications and hard glass sealing. | Property | Value / Condition | Notes | |:---|:---|:---| | **Density** | 8.22 g/cm³ (0.297 lb/in³) | | | **Melting Point** | ~1430 °C (2605 °F) | | | **Rod Diameter Range** | 3.0 mm to 150 mm | Standard sizes available | | **Thermal Expansion Coefficient** | 20-300°C: 8.5-9.2 μm/m·°C
20-400°C: 9.0-9.7 μm/m·°C | Matches borosilicate glass expansion | | **Curie Temperature** | ~480 °C (895 °F) | Critical for CTE matching with hard glasses | | **Thermal Conductivity** | 15.2 W/m·K at 20°C | | | **Electrical Resistivity** | 0.48 μΩ·m at 20°C | | --- #### **3. Mechanical Properties** Typical properties for rod in annealed condition. | Diameter Range (mm) | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Hardness (HRB) | |:---|:---|:---|:---|:---| | 3.0-12.0 | 520-590 | 280-350 | 30-40 | 68-83 | | 12.0-25.0 | 520-590 | 280-350 | 30-40 | 68-83 | | 25.0-50.0 | 510-580 | 270-340 | 30-40 | 65-80 | | 50.0-150.0 | 500-570 | 260-330 | 25-35 | 65-80 | --- #### **4. Product Specifications & Applications** **Rod Specifications:** * **Diameter Tolerances:** ±0.1 mm for diameters <25 mm, ±0.2% for diameters >25 mm * **Straightness:** ≤1 mm per meter length * **Surface Finish:** 3.2 μm Ra (125 μin) standard, 1.6 μm Ra (63 μin) available * **Length:** Standard 3-4 meters, custom lengths available * **Condition:** Annealed, descaled, and polished **Primary Applications:** * **Lead-in Pins and Posts:** Machined electrodes and support pins for hard glass electronic envelopes * **Hermetic Feedthroughs:** Precision-machined connectors for high-reliability systems * **Optical Component Mounts:** Lens holders and positioning rods in scientific instruments * **Vacuum System Components:** Machined flanges and connectors for high-vacuum applications * **Power Tube Components:** Anode and grid supports in high-power electronic tubes * **Semiconductor Equipment:** Machined parts for wafer processing equipment * **Medical Device Components:** Precision parts for implantable devices and diagnostic equipment * **Aerospace Electronics:** Critical components for avionics and satellite systems --- #### **5. International Standards** Comprehensive standardization for rod products. | Standard Type | Standard Number | Title / Specification | |:---|:---|:---| | **ASTM** | **ASTM F15** | Standard Specification for Iron-Nickel Sealing Alloys | | **UNS** | **K94800** | Unified Numbering System Designation | | **AMS** | AMS 7722 | Aerospace Material Specification for Rod and Bar | | **ASTM** | ASTM B48 | Standard Specification for Rod and Bar | | **DIN** | DIN 1745 | Metallic Materials for Glass-to-Metal Seals | | **ISO** | ISO 9711 | Metallic Materials for Glass-to-Metal Seals | --- #### **6. Machining & Processing Characteristics** **Machinability:** * **Machinability Rating:** 40% (compared to free-cutting brass at 100%) * **Recommended Tools:** High-speed steel or carbide with positive rake angles * **Cutting Speed:** 30-45 m/min for turning operations * **Feed Rate:** 0.1-0.3 mm/rev * **Coolant:** Recommended for optimal surface finish **Heat Treatment:** * **Annealing Temperature:** 850-900°C in protective atmosphere * **Stress Relief:** 650-750°C after heavy machining * **Cooling Rate:** Controlled cooling for optimal microstructure **Surface Preparation:** * **Glass Sealing Surface:** Requires clean, oxide-free surface * **Plating Options:** Copper, nickel, or gold plating available * **Pre-oxidation:** Controlled oxidation for immediate glass sealing --- #### **7. Quality Assurance** * **Chemical Analysis:** Heat certification to specified composition * **Dimensional Verification:** 100% diameter and straightness checking * **Surface Inspection:** Visual and dimensional surface quality assessment * **Mechanical Testing:** Tensile and hardness testing per ASTM standards * **Metallurgical Quality:** Grain size control (ASTM 5-7 typical) --- **Summary** **Alloy 48 (Nilo 48) Rod (UNS K94800)** provides a robust, machinable form of this specialized hard glass sealing alloy. Its precisely controlled thermal expansion characteristics, combined with excellent mechanical properties and consistent dimensional quality, make it ideal for manufacturing precision components in aerospace, medical, semiconductor, and high-reliability industrial applications. The rod's ability to be machined into complex components while maintaining perfect thermal expansion matching with hard glasses ensures reliable performance in the most demanding sealing applications. Compliance with **ASTM F15** and other international standards guarantees material consistency and performance reliability across all manufacturing processes.

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 2496 gallon liquid totes Special package is available on request.