Category Archive: Metal Manufacturing

Top Steel Grades for Manufacturing Miniature Components

Nickel vs. Stainless Steel

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Sintering uses pressure and heat to form powdered metal materials into a 80-95% solid mass without fully melting the metal. As the metal granules are pressed together, they begin to bond together the irregular particles to form a “green” compact. These compacts interconnected particles are then sintered to melt the particles together giving the component strength. Powdered metallurgy processes afford the ability to create small net shape parts with complex geometries while generating little waste.

Allied Sinterings, Inc. offers numerous varieties of powdered steel for creating small and miniature parts using the sintering process. This blog will highlight the two most common steel grades we utilize in this manufacturing process – stainless steel and nickel steel.

Advantages of Stainless Steel Components

A steel alloy containing more than 10.5% chromium is considered stainless steel. As one of the most widely used materials, stainless steel is a common base metal for powdered metal processes. The material offers numerous properties that make it an ideal material for producing powdered miniature components. Powdered stainless steel is available in multiple 300 series and 400 series grades.

Some of the beneficial properties of powdered stainless steel include:

  • Corrosion resistance. The chromium within the stainless steel alloy reacts with oxygen to create a protective film on the surface of the metal that protects against corrosive elements.
  • Improved strength. Stainless steel offers good strength and can support significant weight.
  • Durability. Stainless steel’s high corrosion resistance, excellent strength, and broad temperature range make it highly durable in an expansive range of environments.
  • Highly recyclable. As a 100% recyclable material, stainless steel is the most recycled material in the world. Demand remains high enough to outpace the availability of recycled materials, but about 60% of all new stainless steel is generated from recycled material.
  • Wide temperature range. The functional temperature range of stainless steel varies widely based on the specific alloy. Some austenitic alloys used in natural gas applications perform well in temperatures as low as -161°C. Many common grades of stainless steel will maintain their oxidation resistance under exposure to temperatures as high as 870°C, and some specialty alloys can tolerate even higher temperatures.

Sintered stainless steel serves many different types of applications. The medical industry uses powdered metallurgy to develop precision stainless steel parts for critical medical devices. Automotive and industrial equipment often incorporate small, sintered parts, such as gears, as crucial components of larger products. The growing telecom industry turns to sintered stainless steel miniature components for highly complex devices.

The Benefits of Nickel-Steel Alloys

Adding nickel to steel alloys provides a variety of benefits, including:

  • Good formability. The ductile nature of nickel-steel alloys makes them highly formable, which can be beneficial for powdered metals that need additional finishing or machining after the sintering process.
  • Improved strength/toughness. Adding nickel to a steel alloy imparts enhanced strength into the metal while improving resistance to cracking.
  • Good weldability. Nickel improves the weldability of steel by decreasing brittleness and improving welding bonds.
  • Resistance to high operating temperatures. Nickel improves the stability of the protective oxide layer in steel, which helps the layer better tolerate prolonged exposure to high temperatures.

steel componentsNickel steel and nickel stainless steel alloys see broad usage because of their versatility and availability. The pharmaceutical and chemical industries use sintered nickel alloy components within a variety of process equipment. Applications concerned with cleanliness, such as medical or food and beverage facilities, often utilize sintered nickel steel alloy components for their hygienic properties. The aerospace industry prefers nickel alloys for miniature parts for their high strength and ability to operate in a wide temperature range.

Custom Miniature Parts from Allied Sinterings

Stainless steel and nickel steel alloys have become very popular in powdered metallurgy, though selecting the appropriate type of metal for your needs can be difficult. Your sintering provider can help you determine the powdered metal material best suited to your design and specifications.

At Allied Sinterings, we specialize in custom miniature parts for commercial, industrial, and consumer markets. Using state-of-the-art technology in our environmentally controlled facility, our highly experienced technicians can handle virtually any custom powdered metal request, from assemblies and sub-assemblies to precision components for medical devices and process equipment. We can manage low- or high-volume production, offer short lead times on orders over 500 pieces, and can support rush orders when needed.

To see how we can support your project, please contact us today.

What Is Powdered Metal Manufacturing?

Assorted partsAn Overview on Powdered Metal Parts & the Powder Metallurgy Process

Powdered metals are alloys processed into a fine, grain-like powder through one of several processes. Primarily made from stainless steel, brass, copper, iron, or bronze, these metals can be blended with other alloys to achieve the desired material properties and characteristics for a particular application. Offering greater flexibility in material usage and mechanical properties, powdered metal parts can be highly customized and easily reproduced while yielding high-strength, cost-effective components.

Manufacturing High Strength Parts

Powder metallurgy (PM) refers to the manufacturing process by which powdered metals or metal blends are formed to desired specifications through a unique combination of heat and compression to create parts and components that offer improved strength over traditionally forged alternatives. The process is shorter than other manufacturing techniques, with primary steps including the following:

  1. Metals are powdered through solid-state reduction, atomization, electrolysis, or chemical treatments like oxide reduction and thermal decomposition.
  2. Powders are blended with other metals, alloying agents, and lubricants to reduce friction and increase fluidity while yielding a homogeneous mix that will be fed into a rigid toolset for processing.
  3. The metal blend is compacted into the appropriate geometry using dies, punches, hydraulic presses, or other consolidation measures.
  4. Compacted pieces are sintered in a controlled atmosphere using extremely high temperatures to metallurgically bond the particulates.
  5. Parts are subjected to secondary operations depending on the requirements of their final application.

The PM process is recognized as being environmentally friendly as it produces harmless bi-products of nitrogen and hydrogen while also limiting production waste by utilizing more than 97% of the material that enters the process.

Heat Treatments & Finishing Options

After sintering, parts may undergo additional heat treatments or finishing to increase material strength and hardness, improve corrosion resistance, boost part tolerance, enhance surface finish, and more. Secondary operations include things such as:

  • Heat treating: quenching and tempering, steam treating, furnace brazing, etc.
  • Machining: drilling and tapping, turning, milling, or grinding
  • Impregnation: oil or resin
  • Finishing: deburring, tumbling, burnishing, coating or plating, welding, etc.

The Benefits of Powdered Metal Manufacturing

Benefits Of Powdered Metal Manufacturing For High Quality, High Strength Metal Parts To Precision Tolerances

The PM process offers a host of advantages over traditional metal manufacturing practices like forging or die-casting. These benefits include:

  • Cost-effectiveness: PM reduces energy consumption, improves material utilization, and contains fewer steps than other manufacturing approaches, all of which help lower the impact on the bottom line by trimming costs up to 70%.
  • Higher degree of customization: From the creation of unique alloy and lubricant blends designed to meet the material properties of a specific application to the ability to easily produce complex geometries like irregular curves and radial projections, key-ways, splines, counter bores, bosses, axial projections and more, PM allows for greater part customization than other metal manufacturing methods.
  • Minimal machining requirements: With a superior ability to achieve close tolerances, less machining is necessary to produce a final product.
  • Superior surface finish: Net-shaping and tolerance adherence contribute to a reduction in machining needs, which in turn improves surface finish.
  • Repetitive accuracy: The process is suited to moderate- to high-volume production with excellent repetitive accuracy.
  • Materials can be further tailored: Secondary operations allow components to undergo any additional treatments necessary to draw out the material properties most critical for an application’s success, like ductility or hardness.

Custom Powdered Metal Parts From Allied Sinterings

Powdered metal parts provide many advantages that improve part quality and uniformity, shorten production times, and cut down project cost over other manufacturing methods. Allowing for extensive customization and providing repetitive accuracy, powdered metal parts are appropriate in various applications.

At Allied Sinterings, Inc., we apply state-of-the-art powered metal technology to the manufacturing of assemblies, sub-assemblies, medical devices, tools, circuit breakers, and more using custom-blended and brass powders, copper-infiltrated materials, steel, and copper steel. With three sintering furnaces and 42 high-precision presses, an in-house tool room, and a complete tumbling/finishing department, our environmentally controlled facility can manufacture precision parts with outside diameters up to 1.25″, heights up to 1″, and tolerances of ±0.001″.

For more information on custom powdered metal parts or our PM capabilities, contact us today.