Powder metallurgy (PM) is a metalworking process that forms parts by compacting fine metal powders into a desired shape, then heating them in a sintering furnace to bond the particles together. The result is a strong, durable part with high precision and minimal waste.

Powder metallurgy is widely used in the automotive, appliance, industrial, and medical sectors because it allows manufacturers to create complex geometries that would be costly or impossible with traditional machining.

The powdered metal process follows four essential steps:

1. Powder Production: Metal powders are created through atomization, reduction, or electrolysis.
   
   
2. Blending & Mixing: Powders are combined with lubricants or alloying elements for consistency.
   
   
3. Compaction: Powders are pressed in a die under high pressure using hydraulic or mechanical presses.
   
   
4. Sintering: Parts are heated in a controlled-atmosphere furnace, bonding particles without fully melting them.
   
   

Secondary operations, such as machining, coating, or surface treatment, may also be applied for enhanced performance.

The powder metallurgy process offers several advantages:

• Material efficiency: Minimal scrap compared to machining.
  
  
• Cost savings: Economical for high-volume production.
  
  
• Design flexibility: Near-net shapes reduce or eliminate machining.
  
  
• Unique properties: Porosity allows for oil impregnation or filtration.
  
  
• Consistency: Tight tolerances and repeatability across large runs.
  
  

These benefits make PM ideal for industries requiring reliable, cost-effective parts.

Powder metal parts typically achieve a density of 75-95% of wrought material density, depending on compaction pressure, sintering, and material choice. Advanced processes such as copper infiltration or hot isostatic pressing can increase density for applications requiring maximum strength.

Controlled porosity in powder metal parts isn’t a limitation; it’s a design advantage. Porosity enables:

• Oil impregnation for self-lubricating bearings.
  
  
• Filtration applications where fluids or gases must flow through.
  
  
• Improved bonding with coatings or secondary treatments.
  
  
• Reduced weight while maintaining adequate strength.
  
  

For example, a powder metallurgy contact tip can use porosity to manage heat dissipation and lubricant flow, extending service life.

Yes, sintered powder metal parts can be welded, but the process requires special care. Porosity and alloy composition can affect weld strength, so proper preparation and welding techniques are critical. If a part is powder-coated, the coating must be removed before welding to ensure integrity.

To reduce risks, manufacturers often run sample welds or perform nondestructive testing (NDT) on components before production welding. This helps confirm if the part will withstand real-world stresses once in service.

Metal steam treating is a surface treatment that oxidizes the outer layer of sintered metal components. This process:

• Increases surface hardness.
  
  
• Improves wear resistance.
  
  
• Enhances corrosion resistance.
  
  

Steam treating is commonly applied to gears, bearings, and other parts exposed to harsh conditions.

Yes. Powder metallurgy is highly effective for prototyping new designs or testing alternative materials. Prototyping allows engineers to:

• Validate part geometry and tolerances.
  
  
• Test material performance in real-world applications.
  
  
• Adjust designs before full-scale production.
  
  

Prototyping with PM is cost-effective and accelerates the design validation process.

Atlas Pressed Metals manufactures a wide range of part sizes, with capabilities influenced by press stroke length, tonnage capacity, and furnace dimensions. While powder metallurgy (PM) has been typically well-suited for small to mid-sized components, advancements in press and tooling technology have expanded our size capabilities.

Typical part specifications include:

• Weight: From 0.68g (0.0015 lbs) up to 6800g (15 lbs)
  
  
• Diameter: 3mm to 250mm
  
  
• Length: 3mm to 76mm
  
  
• Shapes: Structural, spherical, flanged, single-level, and multi-level
  
  
• Gear Geometries: Flanged, multi-level, helical, and grooved
  
  

These ranges allow us to support a diverse array of applications across industries, delivering precision and performance in every part.

Tooling typically includes dies, punches, and core rods designed for precision compaction. Tooling life depends on:

• Material hardness.
  
  
• Press cycle time.
  
  
• Lubrication and maintenance practices.
  
  

With proper care, PM tooling can last for hundreds of thousands, or even millions, of cycles, making it cost-efficient for high-volume production.

Several factors affect cost, including:

• Press cycle time: Faster cycles lower per-part costs.
  
  
• Sintering furnace used: Energy type and run time matter.
  
  
• Material selection: Different alloys vary in price and performance.
  
  
• Part complexity: Intricate shapes may require advanced tooling or secondary operations.
  
  

PM often outperforms machining on cost at scale, particularly for complex geometries.

• Hydraulic Pressing: Offers slower but highly precise compaction. Ideal for complex parts and prototypes.
  
  
• Mechanical Pressing: Provides faster cycle times and efficiency for high-volume runs.
  
  

Both methods produce consistent results, and the choice depends on part design, production volume, and tolerance requirements.

Designing a new PM part typically follows these steps:

1. Concept & Feasibility: Collaborate on requirements.
   
   
2. Material Selection: Choose based on strength, wear, and cost.
   
   
3. Tooling Design: Develop dies, punches, and compaction tools.
   
   
4. Prototype Production: Validate design and material performance.
   
   
5. Full Production: Scale manufacturing with confidence.

Converting an existing part to powder metallurgy involves:

1. Analysis of Current Part: Geometry, load requirements, and performance expectations.
   
   
2. Design Adjustments: Modify for PM-friendly features.
   
   
3. Material Selection: Match or improve performance vs. wrought/machined part.
   
   
4. Prototyping: Test functionality before full rollout.
   
   
5. Production: Achieve cost savings, reduce waste, and improve high-volume efficiency.