• Methods: Mechanical crushing (ball milling, jaw crushing), physical vapor deposition (PVD), chemical reduction (hydrogen reduction for iron powder), atomization (water/air atomization for alloy powders)
• Key Parameters: Powder particle size (micron-level, affecting forming density), purity, and morphology (spherical/irregular, influencing flowability)

Metal powders are blended with non-metallic additives (carbon, copper for hardness) and lubricants (zinc stearate for moldability) to achieve desired material properties.

• Compression Molding: High pressure (50-300 MPa) in molds to form "green compacts," suitable for simple symmetrical shapes
• Metal Injection Molding (MIM): Powder-binder mixture is injected into molds, debound, and sintered for complex precision parts (watch gears, medical devices)
• Isostatic Pressing: Uniform pressure via liquid (cold/hot isostatic pressing) for high-density materials (aerospace superalloy components)

Heating in a protective atmosphere (argon, hydrogen) or vacuum to 60-80% of the metal's melting point, bonding particles via atomic diffusion to improve density and strength. Critical parameters include temperature, holding time, and atmosphere control.

• Densification: Repressing/re-sintering; hot forging for mechanical properties
• Surface Treatment: Electroplating, painting, carburizing
• Machining: Minor cutting (drilling, grinding) for high precision

• High Material Efficiency: Near-net shaping reduces waste (<5%), lowering costs
• Complex Structure Fabrication: Directly forms parts with microholes, multi-material composites, or gradient properties (oil-impregnated bearings, gearboxes)
• High-Performance Materials: Refractory metals (tungsten, molybdenum), composites (metal-matrix ceramic reinforcements), porous materials (filters, heat sinks)
• Energy-Efficient: Lower energy use than casting/forging, ideal for mass production

• Porosity Impact: Sintered materials retain 5-20% porosity, requiring post-processing for density
• Mold Dependence: High-precision molds are costly and complex, suitable for medium-large scale production
• Size Constraints: Traditional molding limits part size (tens of cm); large components need isostatic pressing or 3D printing

• Iron/Copper-Based: 70%+ of applications, used for gears, bearings, and structural parts (automotive engine components)
• Refractory Metals: Tungsten, molybdenum alloys for aerospace high-temperature parts (rocket nozzles, satellite heat sinks)
• Special Alloys: Titanium alloys, superalloys (Inconel) for aircraft engine blades and medical implants
• Composites: Metal-ceramic (diamond saw blades), porous metals (energy absorption, catalyst supports)

• Automotive: Engine valve seats, transmission gears (30% weight reduction), turbocharger components
• Electronics: MIM-based smartphone camera brackets, 5G heat sinks, magnetic powders for inductors
• Aerospace: Hot isostatic pressed superalloy turbine disks, titanium structural parts
• Medical: Porous titanium implants, MIM dental frameworks
• New Energy: Lithium battery electrode powders, fuel cell bipolar plates