While traditional forms of metal manufacturing like forging and casting have been around for hundreds of years, there are some applications where the best option is powder metallurgy manufacturing.

In this article, we’ll look at how powder metallurgy works, including which parts are best suited to the process. We’ll also go through the many powder metallurgy benefits you’ll enjoy.

What Is Powder Metallurgy Manufacturing?

Powder metallurgy refers to the material used to manufacture parts. This process uses a metal powder produced through a process called atomization, where molten metal is broken down by a high-speed spray of fluid or inert gas, then solidified into a powder as it cools.

The powder is then poured into a mold and compressed until it reaches the desired shape and density.

There are a number of ways you can adjust this process, of course. You can create alloys by mixing metal powders, and you can introduce a number of other materials as well, including abrasive surfaces, carbide tips, and materials intended to increase friction, which is the case when manufacturing brake pads.

Parts can also be sintered, which involves heating the parts to temperatures just below the melting point. This adds strength and durability and can also affect porosity, which is a vital element in manufacturing self-lubricating parts like bearings.

Powder metallurgy manufacturing combines flexibility and cost savings with high precision and accuracy, making it ideal for applications that otherwise might cost time and money you can’t afford to spend.

Ideal Parts for Powder Metals

While powder metallurgy manufacturing is not ideal for all use cases, there are many situations in which it is by far the superior technique. Typically, these parts tend to be smaller and more intricate, and they may have additional properties, like being magnetic.

Using traditional means of fabricating these small and more detailed parts would typically require a great deal of millwork. The sheer volume of the machining aside, maintaining consistency in all details on such intricate parts would be a challenge.

Instead, powder metallurgy allows parts to be fabricated as close as possible to their finished form, improving consistency while eliminating extra work.

Benefits of Powder Metal Manufacturing

There are a number of powder metallurgy benefits that you just can’t achieve when manufacturing metal components by other methods. Here are some of the most significant ways you could gain from this process.

Cost-Effectiveness

One of the most important powder metallurgy benefits that companies will notice is that the process is quite cost-effective. This is due to a number of factors, including the following.

Less Machining

Because parts are fabricated as close as possible to the final expected dimensions, there is very little machining that needs to be done in order to clean up the piece, saving both time and money.

Less Scrap

In other metal manufacturing processes, there’s usually a great deal of wasted product, and while much of that is reclaimed and recycled, each step in the recycling process costs money.

With powder metallurgy, most parts incorporate over 97% of the raw material, virtually eliminating waste. This is because powder metallurgy makes use of additive manufacturing principles, rather than subtractive manufacturing.

Scalability for High Volume

Powder metallurgy is an easily replicable process, which means that you can manufacture parts at a high volume. In fact, the most cost-effective use of this method is to produce more than 10,000 of each part per year!

Superior Finish

The powder metallurgy process produces an excellent surface finish on your final parts, and they can also have secondary finishes applied after sintering to add more resistance to wear or corrosion or to improve the part’s strength.

One of the other powder metallurgy benefits is its superior porosity compared to traditional methods. Because the manufacturing process determines the density of the final product, it is possible to create a more porous finish that will absorb lubricants, allowing you to create self-lubricating parts.

Unique Materials

Because powder metallurgy works by using a solid metal powder, it allows you to produce a wide number of unique parts with special properties that are difficult to replicate with other methods.

For instance, you can create a number of alloys that would be difficult or impossible to recreate with traditional methods, such as materials made for electrical contacts or metals with extremely high melting points.

One of the first uses for powder metallurgy was actually to create the tungsten blocks used to make incandescent light bulb filaments.

Powder metallurgy also lets you create products with specific characteristics. A large number of magnets are manufactured in this way.

Steel parts that are required to work at high speeds can benefit from the extra durability and performance they get from the powder metallurgy process, too.

It’s also possible to mix other materials into the powder during the manufacturing process. The linings of brakes, for instance, have non-metallic materials added during the powder metallurgy process that increase the friction of the surface. These materials are deeply embedded in the metallic matrix, ensuring that the friction properties can remain constant.

High-Performance Parts

This last point, the superior performance offered by powder metallurgy manufacturing, is one of the most important benefits offered by the process.

The sintering process provides excellent strength and durability for parts of all types, and the self-lubricating properties of some applications have become industry standards.

Powder metallurgy can also create components for use in airplane engines using nickel or cobalt superalloys. These alloys are not able to be replicated by other manufacturing techniques.

The tremendous precision the powder metallurgy process offers allows manufacturers to control the microstructure of every part to ensure proper performance within expected temperature ranges.

Looking for More Information About Powder Metallurgy Benefits?

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Advantages of Powder Metallurgy (PM) and How It Compares To Other Manufacturing Methods

General Advantages of Powder Metallurgy

• A unique or complex shape that would be impossible, costly, or impracticable to manufacture using other metal forming technologies.
• Part-to-part reproducibility and repeatability with tight dimensional requirements over moderate to high volume applications.
• Long-term reliability in critical applications.
• Controlled porosity for self-lubrication
• Unique requirements that may be solved with the appropriate material selection and processing strategies.
• Specific strength, wear resistance, and surface finish requirements.
• Cost competitive through reduced material losses and eliminating or minimizing secondary operations such as machining.

Advantages of Powder Metallurgy vs. Casting

Casting is the process where molten metal is injected into a mold and allowed to harden to form the part. The materials used are normally non-ferrous, primarily aluminum, magnesium, and zinc alloys.

The decision to use a specific metal forming technology is dependent on part complexity, specific mechanical requirements and application, production volume and part life, and cost consideration.

Advantages of the selection of Powder Metallurgy over Die Casting include:

• Design flexibility utilizing casting is limited by the need for draft angles, parting line considerations, and wall thickness, whereas the powder metal process allows for complex shapes and intricate features, and, when appropriate, controlled porosity.
• The need for specific production volumes and part life are both excellent using the die-casting process or the powder metallurgy process; however, powder metal provides better material utilization, as there is very little waste generated.
• The investment in the die and the tools in the Die Casting process can be expensive, whereas the cost of the tools used in powder metal can range from very inexpensive to expensive depending on the part geometry, the material used, and size.

Advantages of Powder Metallurgy vs. Forging

Forging is the process of producing metal parts through mechanical deformation using compressive forces where the part is shaped without removing or adding material. Almost any type of metal or combination of metals can be forged. Selecting the correct material depends on the part's requirements in its application. The most common materials are stainless steel, titanium, carbon steels, and other metal alloys.

The decision to use a specific metal forming technology is dependent on part complexity, specific mechanical requirements and application, production volume and part life, and cost consideration.

Advantages of the selection of Powder Metallurgy over Forging include:

• Design flexibility utilizing forging is limited by the size of the press, and the ability to produce simple shapes, whereas the powder metal process allows for complex shapes and intricate features, and, when appropriate, controlled porosity.
• The need for specific production volumes and part life are both excellent using the forging process or the powder metallurgy process; however, PM provides better material utilization, as there is very little waste generated. Forging, although producing a strong final part, typically requires machining to provide an appealing finished product.
• The capital investment is significant in the forging process for the die and the press. Additionally, labor, tooling, and material costs may need to be considered. The cost of the tools used in powder metal can range from very inexpensive to expensive depending on the part geometry, material used, and size.

Advantages of Powder Metallurgy vs. Stamping

Stamping is the process of producing metal parts by pressing or punching metal sheet (or coiled metal) with a stamping press using a tool and die to form the part. Almost any type of metal or combination of metals can be forged. The selection of materials to use in this process is determined by the application, formability, welding requirements, corrosion resistance, strength, and cost.  The most common materials are aluminum, stainless steel, carbon steels, and copper and brass.

Advantages of the selection of Powder Metallurgy over Stamping include:

• Design considerations utilizing the stamping process include knowledge about how the metal will be deformed, as well as required radii, angles, and dimensional requirements. The powder metal process allows for complex shapes and intricate features not normally available through stamping.
• High-volume production is suitable for stamping and powder metal processes; however, stamping produces a considerable amount of excess material (scrap), where PM provides better material utilization, as there is very little waste generated. 
• The capital investment/ as well as high set-up costs are significant in the stamping process as stamping dies are expensive and increase in cost as the part becomes more complex. The cost of the stamping machines can also be costly, which further impacts the overall cost of production. The cost of the tools used in powder metal can range from very inexpensive to expensive depending on the part geometry, material used, and size.

Advantages of Powder Metallurgy vs. Machining

Machining is a general term that covers many processes to remove material from a solid metal blank to produce the desired part. Examples of common machining processes are CNC turning, laser cutting, water jet cutting, and milling. The decision to use the machining process and the material selected depends on the finished part's complexity, the application's dimensional and tolerance requirements, and the volume and timeframe needed to manufacture the finished component. Depending on the above considerations, materials used in the machining process include aluminum, brass, bronze, copper, carbon steel, stainless steel, tool steel, alloys, and in some cases, plastics.

As part of producing a finished part, a machining process is often used in combination with powder metallurgy, forging, die casting, and stamping. It is often considered a secondary operation to those metal-forming technologies.

Advantages of the selection of Powder Metallurgy over Machining include:

• Powder metallurgy allows for complex shapes and intricate detail in a less costly manner, as there is minimal waste and better material utilization. However, a machined part may have superior dimensional accuracy, tighter tolerance, and improved surface finishes. 
• Depending on the machining process selected, cutting tools are expensive, and the lead times are often long. The ability to meet high production volumes with a machining process is limited by the machining process selected.