Alloy 404,Monel 404 Other/Similar Specs,,E FORU

British Specs:，American Specs:，German Specs:

### **Product Datasheet: Alloy 404 / Monel® 404** **A Low-Cost, High-Conductivity Nickel Alloy with Controlled Low Permeability** --- #### **Overview** Alloy 404 (commonly known by its trade name **Monel 404**) is a non-age-hardenable, binary nickel-copper alloy specifically engineered for specialized electronic and electrical applications. Its primary characteristics include a uniquely low and stable magnetic permeability, excellent electrical conductivity, and good brazing characteristics. It is designed as a cost-effective alternative to pure nickel in applications where these properties are critical. The alloy's composition is carefully controlled to minimize cobalt and iron content, which are common impurities that can increase magnetic permeability. This makes Alloy 404 an ideal choice for vacuum tubes, transmitting tubes, and other high-frequency electronic components. --- #### **Key Features & Advantages** * **Controlled Low Magnetic Permeability:** Maintains a permeability of less than 1.005, even after severe cold working, making it essentially non-magnetic. * **Excellent Electrical Conductivity:** Higher conductivity than many other nickel-copper alloys, suitable for electrical components. * **Good Thermal Conductivity:** Effective for heat dissipation. * **Superior Brazing Characteristics:** Excellent for use with high-temperature brazing alloys in hydrogen atmospheres without risk of embrittlement. * **Good Corrosion Resistance:** Resists atmospheric corrosion, fresh water, and steam, typical of nickel-copper systems. * **Cost-Effective:** A more economical option compared to pure nickel for specific electronic applications. --- #### **Chemical Composition (Weight % - Typical)** The composition is tightly controlled to achieve its specific magnetic and electrical properties. | Element | Content (%) | | :--- | :--- | | **Nickel (Ni)** | 52.0 - 57.0 | | **Copper (Cu)** | Balance | | **Manganese (Mn)** | 0.10 max | | **Iron (Fe)** | 0.25 max | | **Silicon (Si)** | 0.10 max | | **Carbon (C)** | 0.15 max | | **Sulfur (S)** | 0.024 max | | **Cobalt (Co)** | 0.10 max | | **Magnesium (Mg)** | 0.05 - 0.15 | *Note: The low iron and cobalt content is critical for its low magnetic permeability.* --- #### **Physical Properties** | Property | Value / Condition | | :--- | :--- | | **Density** | 8.91 g/cm³ (0.322 lb/in³) | | **Melting Point** | 1300 - 1350 °C (2370 - 2460 °F) | | **Electrical Resistivity** | ~29 μΩ·cm at 20°C | | **Thermal Conductivity** | ~29 W/m·K at 20°C | | **Thermal Expansion Coefficient** | 13.9 μm/m·K (20-100°C) | | **Magnetic Permeability** | **< 1.005** (Annealed and Cold Worked) | | **Curie Temperature** | < -100 °C (-148 °F) | --- #### **Mechanical Properties (Typical)** Properties can vary with form and temper. **Sheet & Strip (Annealed)** * **Tensile Strength:** 380 - 480 MPa (55 - 70 ksi) * **Yield Strength (0.2% Offset):** 140 - 240 MPa (20 - 35 ksi) * **Elongation (in 2"):** 35 - 45% **Sheet & Strip (Hard Temper)** * **Tensile Strength:** 550 - 620 MPa (80 - 90 ksi) * **Yield Strength (0.2% Offset):** 515 - 585 MPa (75 - 85 ksi) * **Elongation (in 2"):** 2 - 10% --- #### **International Standards** Alloy 404 is covered by several international standards, which may specify slightly different forms or tempers. * **ASTM (USA):** * **ASTM B164:** Standard Specification for Nickel-Copper Alloy Rod, Bar, and Wire. * **ASTM F96:** Standard Specification for Electronic Grade Alloys (Covers sheet, strip, and foil). * **UNS (Unified Numbering System):** **N04404** * **AMS (Aerospace Material Specification):** **AMS 4571** (Bar, Forging, and Ring) * **ISO (International Organization for Standardization):** Not as widely standardized as other Monel alloys, but specifications are often agreed upon between supplier and customer based on ASTM requirements. --- #### **Product Applications** Alloy 404 is predominantly used in the electronics and electrical industries where its specific properties are essential. * **Electron Tubes & Vacuum Tubes:** Anodes, grids, and other internal structures where low magnetic permeability is critical to prevent interference with the electron beam. * **Waveguides & RF Components:** Used in components for radar and communication systems. * **Transistor Housings & Electronic Packaging:** Provides a hermetic seal and shields sensitive components. * **Leads & Terminals:** For glass-to-metal seals in hermetic connectors and feedthroughs due to its matched thermal expansion with certain glasses. * **Brazing Preforms:** Used as a filler metal base for joining components. * **Cryogenic Applications:** Maintains toughness and low permeability at very low temperatures. --- #### **Other / Similar Specifications & Alloys** While Alloy 404 is unique, it is part of a family of nickel-copper alloys. It's important not to confuse it with its more common counterparts. | Alloy Name | Key Characteristics | Primary Difference from Alloy 404 | | :--- | :--- | :--- | | **Monel® 400 (Alloy 400)** | Excellent general corrosion resistance in a wide range of environments. | Contains ~1.5% Fe, making it slightly magnetic and unsuitable for low-permeability applications. | | **Monel® R-405 (Alloy R405)** | Similar to Alloy 400 but with added sulfur for improved machinability. | Higher sulfur content; not designed for low-permeability or high-purity brazing. | | **Monel® K-500 (Alloy K-500)** | Age-hardenable version with higher strength and hardness. | Contains aluminum and titanium; can be magnetic after aging; used for shafts, valves, and fasteners. | | **Pure Nickel (Alloy 200/201)** | Very high electrical and thermal conductivity, excellent corrosion resistance. | More expensive and can have higher magnetic permeability than the carefully controlled Alloy 404. | --- **Disclaimer:** *Monel® is a registered trademark of Special Metals Corporation (a PCC company).* The information provided herein is for reference purposes only. Properties are typical and may vary based on product form, size, and processing. For critical applications, consultation with the material supplier and verification of properties for the specific lot is recommended.

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 2947 gallon liquid totes Special package is available on request.