Active Standard ASTM A839 | Developed by Subcommittee: A06.02
Book of Standards Volume: 03.04
Historical (view previous versions of standard)
This specification covers parts produced from pressing and sintering of iron-phosphorus powders. The specification does not cover parts produced by metal injection molding. These parts are used in magnetic applications requiring higher permeability and electrical resistivity and lower coercive field strength than routinely attainable in parts produced from unalloyed iron powder. Two powder types are covered: Type I containing nominally 0.45% phosphorus, and Type II containing nominally 0.8% phosphorus. Apart from chemistry, parts produced to this specification shall have a minimum sintered density and maximum allowable coercive field strength. The minimum sintered density shall be 6.8 g/cm3 (6800 kg/m3) in the magnetically critical section of the part. Three grades with increasing maximum allowable coercive field strength are defined for each powder type. Detailed appendices showing the effect of sintering conditions on the magnetic and mechanical properties of parts made from both powders are included in this specification.
This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
1.1 This specification covers parts produced from iron-phosphorus powder metallurgy materials. These parts are used in magnetic applications requiring higher permeability and electrical resistivity and lower coercive field strength than attainable routinely from parts produced from iron powder.
1.2 Two powder types are covered; Type I containing nominally 0.45 % phosphorus, and Type II containing nominally 0.8 % phosphorus.
1.3 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.
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that 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.
A34/A34M Practice for Sampling and Procurement Testing of Magnetic Materials
A596/A596M Test Method for Direct-Current Magnetic Properties of Materials Using the Ballistic Method and Ring Specimens
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
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 Number Code 77.160 (Powder metallurgy)
UNSPSC Code 31381200(Sintered magnets and magnet assemblies)