{"id":2466,"date":"2023-11-21T03:44:33","date_gmt":"2023-11-21T03:44:33","guid":{"rendered":"https:\/\/met3dp.com\/?p=2466"},"modified":"2023-11-21T03:45:14","modified_gmt":"2023-11-21T03:45:14","slug":"mim-additive-manufacturing-20231121","status":"publish","type":"post","link":"https:\/\/met3dp.sg\/zh\/mim-additive-manufacturing-20231121\/","title":{"rendered":"MIM \u5feb\u901f\u6210\u578b\u5236\u9020"},"content":{"rendered":"\n

mim additive manufacturing<\/a> refers to an industrial process to produce small, complex metal parts at high volumes. A composite metal powder feedstock is molded into a green-state shape using injection molding equipment, debound, and then sintered to achieve full density.<\/p>\n\n\n\n

MIM leverages the geometric flexibility of polymer injection molding and green-forming with the performance capability of metal alloys. With additive manufacturing processes expanding options, this guide covers MIM compositions, properties, applications, specifications, process flows, suppliers, tradeoffs, and FAQs.<\/p>\n\n\n\n

\"mim<\/figure>\n\n\n\n

Composition of MIM Alloys<\/h2>\n\n\n\n

Many compositions are available as MIM feedstocks:<\/p>\n\n\n\n

Material<\/th>Common Alloys<\/th>Overview<\/th><\/tr><\/thead>
Stainless steel<\/td>316L, 17-4PH, 420<\/td>Corrosion resistant, high hardness, for medical uses<\/td><\/tr>
Tool steel<\/td>H13, P20<\/td>High strength, heat resistance, for molded tooling<\/td><\/tr>
Aluminum alloy<\/td>2024, 6061, 7075<\/td>Lightweight, high strength-to-weight ratio<\/td><\/tr>
Titanium alloy<\/td>Ti-6Al-4V<\/td>Lightweight with corrosion resistance and high strength for aerospace uses<\/td><\/tr>
Nickel alloy<\/td>Inconel 625 and 718<\/td>Heat\/corrosion resistance suited for turbo machinery<\/td><\/tr>
Tungsten<\/td>WHA, WC<\/td>Extremely high density perfect for balancing applications<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Both standard and custom formulations are available depending on needs.<\/p>\n\n\n\n

Properties of mim additive manufacturing<\/a><\/h2>\n\n\n\n

In addition to composition tailored to performance requirements, key resulting properties include:<\/p>\n\n\n\n

Property<\/th>Description<\/th><\/tr><\/thead>
Density<\/td>Ranges from near pure metal density to greater than 95% theoretical density<\/td><\/tr>
Tensile strength<\/td>250 MPa to over 1300 MPa depending on reinforcement strategies<\/td><\/tr>
Hardness<\/td>Up to 70 HRC achieved based on alloy choice<\/td><\/tr>
Corrosion resistance<\/td>Varying resistance levels possible based on compositions selected<\/td><\/tr>
Surface roughness<\/td>As molded <6 \u03bcm Ra up to <0.2 \u03bcm Ra after plating\/polishing<\/td><\/tr>
Complex geometry<\/td>Molding allows intricate shapes unachievable with other processes<\/td><\/tr>
Feature resolution<\/td>Small slots, holes, threads down to ~100 \u03bcm \u00bb achievable<\/td><\/tr>
Wall thickness<\/td>As low as ~0.25 mm walls molded based on geometry<\/td><\/tr>
Tolerances<\/td>Tighter tolerances than metal AM, typical \u00b10.3% of dimensions<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

These capabilities make MIM suitable for end-use precision components.<\/p>\n\n\n\n

Applications of MIM Additive Manufacturing<\/h2>\n\n\n\n

MIM\u2019s geometric flexibility and tailored composition suit various industries:<\/p>\n\n\n\n

Industry<\/th>Component Examples<\/th><\/tr><\/thead>
Automotive<\/td>Gears, rocker arms, turbocharger components<\/td><\/tr>
Aerospace<\/td>Turbine blades, impellers, nozzle guide vanes<\/td><\/tr>
Firearms<\/td>Triggers, safeties, slides, ejectors, muzzles<\/td><\/tr>
Medical\/Dental<\/td>Scalpel handles, forceps, skull plates, crowns<\/td><\/tr>
Oil and Gas<\/td>Valve parts including bodies, stems, actuators<\/td><\/tr>
Micro Electronics<\/td>Shields, connectors, pins, spacers, actuators<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

MIM also helps create tooling inserts capable of mass production molding\/forming operations.<\/p>\n\n\n\n

MIM Feedstock Specifications<\/h2>\n\n\n\n

Feedstock properties require careful control for tolerance and feature capability:<\/p>\n\n\n\n

Parameter<\/th>Typical Specification<\/th>Test Method<\/th><\/tr><\/thead>
Powder particle size<\/td>3 \u2013 20 \u03bcm<\/td>Laser diffraction<\/td><\/tr>
Powder loading<\/td>>55 vol%<\/td>Thermogravimetric analysis<\/td><\/tr>
Powder apparent density<\/td>2.5 \u2013 4 g\/cm3<\/td>Hall flowmeter<\/td><\/tr>
Tap density<\/td>>4 g\/cm3<\/td>Tapping volumeter<\/td><\/tr>
Viscosity curve<\/td>Shear rate dependent<\/td>Capillary rheometry<\/td><\/tr>
Pellet size distribution<\/td>2 \u2013 4 g sensitive to shape<\/td>Sieving<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

These specifications promote mold flow while ensuring green-body and sintered strength.<\/p>\n\n\n\n

Overview of the MIM Manufacturing Process<\/h2>\n\n\n\n
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  1. Develop composite feedstock with desired powder + binder system<\/li>\n\n\n\n
  2. Pelletize feedstock for precision volumetric shot control<\/li>\n\n\n\n
  3. Injection mold parts with tight tolerances and surface finish<\/li>\n\n\n\n
  4. Chemically debind and remove polymer content<\/li>\n\n\n\n
  5. Sinter pellets at >92% theoretical density<\/li>\n\n\n\n
  6. Machine features as needed if geometry allows<\/li>\n\n\n\n
  7. Apply supplementary plating, heat treating, coating, etc. if necessary<\/li>\n\n\n\n
  8. Quality assurance testing and validation for production<\/li>\n<\/ol>\n\n\n\n

    This continues to be optimized for reliability at high volumes.<\/p>\n\n\n