ASTM A904-04

    Historical Standard: ASTM A904-04 Standard Specification for 50 Nickel-50 Iron Powder Metallurgy (P/M) Soft Magnetic Parts

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    ASTM A904

    1. Scope

    1.1 This specification covers the magnetic properties of 50 nickel-50 iron parts fabricated by powder metallurgy techniques and is intended for parts that require high magnetic permeability, high electrical resistivity, low coercive field strength, and low hysteresis loss. It differs from the wrought alloy specification (see Specification A 753) because these parts are porous. A number of magnetic properties such as permeability are proportional to the sintered density.

    1.2 This specification deals with P/M parts in the sintered or annealed condition. Should the sintered parts be subjected to any secondary operation that causes mechanical strain, such as machining or sizing, they should be resintered or annealed.

    1.3 The values stated in customary (cgs-emu and inch-pound) units are to be regarded separately as standard. The values given in parentheses are mathematical conversions to SI units, which are provided for information only and are not considered standard.


    2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

    ASTM Standards

    A34/A34M Practice for Sampling and Procurement Testing of Magnetic Materials

    A340 Terminology of Symbols and Definitions Relating to Magnetic Testing

    A596/A596M Test Method for Direct-Current Magnetic Properties of Materials Using the Ballistic Method and Ring Specimens

    A753 Specification for Wrought Nickel-Iron Soft Magnetic Alloys (UNS K94490, K94840, N14076, N14080)

    A773/A773M Test Method for dc Magnetic Properties of Materials Using Ring and Permeameter Procedures with dc Electronic Hysteresigraphs

    B328 Test Method for Density, Oil Content, and Interconnected Porosity of Sintered Metal Structural Parts and Oil-Impregnated Bearings

    B962 Test Methods for Density of Compacted or Sintered Powder Metallurgy (PM) Products Using Archimedes Principle

    E1019 Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys by Various Combustion and Fusion Techniques


    ICS Code

    ICS Number Code 77.160 (Powder metallurgy)

    UNSPSC Code

    UNSPSC Code 31381200(Sintered magnets and magnet assemblies)


    DOI: 10.1520/A0904-04

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