{"id":1487,"date":"2023-12-18T04:55:35","date_gmt":"2023-12-18T04:55:35","guid":{"rendered":"https:\/\/am-printing.com\/?p=1487"},"modified":"2023-12-18T04:56:46","modified_gmt":"2023-12-18T04:56:46","slug":"high-temperature-iron-powder-20231218","status":"publish","type":"post","link":"https:\/\/am-printing.com\/ja\/high-temperature-iron-powder-20231218\/","title":{"rendered":"\u9ad8\u6e29\u9244\u7c89"},"content":{"rendered":"\n

High temperature iron powders<\/a> refer to specialized metallic iron powders designed to operate at elevated temperatures beyond 700\u00b0C without rapidly oxidizing or losing strength. These advanced materials expand the usable temperature range of iron while retaining magnetic properties, making them critical for modern applications including electromagnetic devices like motors, actuators, sensors and transformers.<\/p>\n\n\n\n

Overview of High Temperature Iron Powder<\/strong><\/h2>\n\n\n\n

High temperature iron powders are produced by thermally stable insulative coatings on iron particles, alloying additions, or other proprietary methods to impart oxidation and corrosion resistance for sustained performance in warmer environments.<\/p>\n\n\n\n

These powders retain high saturation induction and low core losses at 400-700\u00b0C, unlike conventional iron which suffers from rapid deterioration of magnetic properties beyond 300\u00b0C. Their thermal endurance allows miniaturized electromagnetic components to handle higher power densities.<\/p>\n\n\n\n

Types of High Temperature Iron Powder<\/strong><\/h2>\n\n\n\n

Several distinct material technologies exist for imparting thermal stability:<\/p>\n\n\n\n

Type<\/strong><\/th>Description<\/strong><\/th><\/tr><\/thead>
Silicon coated iron<\/td>Iron particles encapsulated by thin silica layer<\/td><\/tr>
Alloyed iron powder<\/td>Small additions of Al, Si, Cr increase temperature resistance<\/td><\/tr>
Annealed carbonyl iron<\/td>Improved insulation minimizes eddy current losses<\/td><\/tr>
High purity iron<\/td>99.5%+ iron content raises operating ceiling<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Silicon coated, alloyed and high purity iron powders dominate the landscape of commercially available high temperature grades. Each approach has relative advantages and limitations.<\/p>\n\n\n\n

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Composition of High Temperature Iron<\/strong><\/h2>\n\n\n\n

While the base composition is >90% iron for most high temperature grades, various alloying additions or coatings are used to curb oxidation around 500-600\u00b0C. Some typical compositions are:<\/p>\n\n\n\n

Material<\/strong><\/th>Composition<\/strong><\/th><\/tr><\/thead>
Silicon coated iron<\/td>96-98% Fe, 2-4% SiO2 coating<\/td><\/tr>
Alloyed iron<\/td>Up to ~3% Cr, 2% Al, 1% Si<\/td><\/tr>
High purity iron<\/td>99.5%+ iron, 0.01% C, low oxygen<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Maintaining high iron content is vital for enabling elevated Curie temperatures while additions protect powders against rapid air oxidation. Balancing magnetic performance and temperature resistance is key.<\/p>\n\n\n\n

Properties of High Temperature Iron Powder<\/a><\/strong><\/h2>\n\n\n\n

Key properties of high temperature iron powders are:<\/p>\n\n\n\n

Property<\/strong><\/th>Typical Value<\/strong><\/th><\/tr><\/thead>
Saturation induction<\/td>1.7-2.1 Tesla up to 500\u00b0C<\/td><\/tr>
Resistivity<\/td>~1.0-1.4 x 10<sup>-7<\/sup> \u03a9m<\/td><\/tr>
Curie temperature<\/td>750 \u2013 1050\u00b0C<\/td><\/tr>
Thermal conductivity<\/td>25-35 W\/mK<\/td><\/tr>
Density<\/td>7.1 \u2013 7.4 g\/cm3<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Exceptional saturation magnetization persistence versus temperature paired with electrical resistivity form the foundation for high efficiency in motors, transformers, inductors etc.<\/p>\n\n\n\n

Characteristics of High Temp Iron Powders<\/strong><\/h2>\n\n\n\n

Critical characteristics differentiating commercially available high temperature iron powders include:<\/p>\n\n\n\n

Characteristic<\/strong><\/th>Significance<\/strong><\/th><\/tr><\/thead>
Temperature resistance<\/td>Oxidation protection determines upper limit<\/td><\/tr>
Saturation induction<\/td>Magnetic strength heavily influences efficiency<\/td><\/tr>
Resistivity<\/td>Higher is better for minimizing eddy current losses<\/td><\/tr>
Particle size distribution<\/td>Affects powder pressing and sintered density<\/td><\/tr>
Compactability<\/td>High green\/sintered density improves properties<\/td><\/tr>
Flowability<\/td>Impacts ease of powder handling during processing<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Balancing thermal stability and magnetic performance defines the quality and value proposition of these premium powders.<\/p>\n\n\n\n

Applications of High Temperature Iron<\/strong><\/h2>\n\n\n\n

The unique properties of high temperature iron powders make them ideally suited for:<\/p>\n\n\n\n

High Temperature Iron Applications<\/strong><\/p>\n\n\n\n

Category<\/strong><\/th>Applications<\/strong><\/th><\/tr><\/thead>
Automotive<\/td>Ignition coils, traction motors, sensors<\/td><\/tr>
Aerospace<\/td>generators, actuators, relays<\/td><\/tr>
Power<\/td>Grounding transformers, reactors, energy meters<\/td><\/tr>
Electronics<\/td>Magnetic amplifier cores, inductor cores<\/td><\/tr>
Chemical<\/td>Reactors vessels, high temperature reactors<\/td><\/tr>
Equipment<\/td>Wind turbines, heavy electrical systems<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Exceptional thermal persistence of magnetic flux density combined with design flexibility using powder metallurgy enables next generation electric machine designs across transportation, energy and industrial systems.<\/p>\n\n\n\n

Specifications of High Temperature Iron Powder<\/strong><\/h2>\n\n\n\n

High temperature iron powders must meet exacting standards concerning properties and powder characteristics:<\/p>\n\n\n\n

Parameter<\/strong><\/th>Typical Specification<\/strong><\/th>Test Standard<\/strong><\/th><\/tr><\/thead>
Apparent density<\/td>2.7 \u2013 4 g\/cm3<\/td>ASTM B243<\/td><\/tr>
Tap density<\/td>3.6 \u2013 5 g\/cm3<\/td>ASTM B527<\/td><\/tr>
Compacted density<\/td>6.8 \u2013 7.4 g\/cm3<\/td>MPIF 42<\/td><\/tr>
Induction (500\u00b0C)<\/td>> 1.4 Tesla<\/td>ASTM A773<\/td><\/tr>
Resistivity (500\u00b0C)<\/td>> 7×10<sup>-6<\/sup> \u03a9m<\/td>ASTM B43<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

International testing standards help qualify magnetic performance, densification response and electrical properties following exposure to elevated operating temperatures around 500\u00b0C.<\/p>\n\n\n