What Is Sintered Powdered Metal?

Powder metallurgy involves using metallic powders to produce finished or semi-finished shaped components. It is becoming an increasingly popular option for traditional casting to create application-specific metal parts.

However, while the compaction process performs most of the work, Compacting pressures will only attain up to about 90% of theoretical densities. PM compacting is a net shape or close to net shape process. Here is where sintering comes into play.

In this article, we will delve into the fundamentals of the sintering process in powder metallurgy, including its definition, benefits, and applications.

Definition of Sintering

Sintering is used to provide strength and a stabilizing agent to a material. The sintering of powdered metals is a process in which particles Physically bond under pressure to create a cohesive “green” shape and  when subjected to sintering temperature compacted particles then bond. Typically, the temperature at which the particles are sintered is below the melting point of the powder’s primary material.

Before the actual sintering process, choosing a powder composition that will produce the desired results is crucial. The powder mixture will contain essential elements — such as copper, iron, molybdenum, and nickel — plus other substances like lubricants and flow enhancers. These will help in improving the powder’s flow into the die. Then, the powder is pressed with extreme force and high pressure to fuse it.

After the powder has been compacted, the sintering process begins by transferring the parts through a highly controlled Hydrogen/ nitrogen atmosphere  furnace . The objective is to maintain a temperature just below the melting point of the metal, but not completely. Finally, the sintered components are prepared for additional finishing and or secondary heat treatments to achieve the desired properties.

Benefits of Sintered Powdered Metal Products

Sintering enables manufacturers to replace costly metalworking techniques — such as cutting, casting, and stamping — with a more economical alternative. Here are some additional benefits of sintered powdered metal products:

  • Environmentally friendly
  • Excellent tolerance control
  • Good performance properties in parts
  • Superior surface finishes
  • High levels of uniformity and purity
  • Reduced costs due to minimal material waste
  • Sound dampening
  • Self lubricating

Applications of Sintered Powdered Metals

Sintering has a wide range of applications in various industries. For example, sintered stainless steel is utilized as filtering material in applications requiring high thermal stability and the ability to regenerate the filter component. On the other hand, sintered silver and gold are frequently used to create small jewelry items.

This process is also one of the few feasible manufacturing techniques for metals with low melting points, including bronze, copper, molybdenum, tungsten, and osmium. Particularly, sintered bronze is used as a bearing material due to its porosity, enabling lubricants to flow through or remain trapped within it. Meanwhile, sintered copper is used as mainly heat sinks and corrosive environments

Sintered powdered metals are also utilized in the military and defense industries. Artillery and grenade launcher detonators and timers.  The process also works well for net shape gun parts such as front and rear sights. Sporting rifles contain many PM components due to there quality and reliability

Allied Sinterings for Quality Powdered and Sintered Metal Parts

Since 1959, Allied Sinterings has provided powdered and sintered metal products using powders and materials of the highest quality. Our proficiency with complex and intricate geometries enables us to serve numerous industries, including the automotive, medical, telecommunications, and industrial equipment sectors.

Contact us today to learn more about our capabilities or request a quote to get started with Allied Sinterings!


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