The Four Steps of the Powder Production Line

Powder Production Line includes four distinct steps: blending and mixing, pressing, sintering, and cooling. Each of these steps requires specialized equipment to achieve positive results.

There are various methods to produce metal powders, namely atomization, solid-state reduction, and chemical treatments. Each method is designed to fit the specific needs of each workpiece.

Raw Materials

Raw materials are the building blocks of matter. They have driven the imaginations of philosophers, scientists, and artists for millennia. For manufacturers, however, they have a more concrete existence as powders. Powder processing technology conditions these primary materials to produce a vast range of products, from chemicals and pharmaceuticals to ceramics and metals.

Metal powders can be made by crushing, granulation, or atomization. Different atomization methods produce distinct particles of varying sizes and shapes. The particles must also be free of contaminants such as impurities and agglomerates, as well as having the right characteristics for their specific applications. This includes grain shape (spherical, irregular, or granulated), particle size distribution, and density.

Another important aspect is the tendency of the particles to oxidize and their sintering behavior. Some of these factors can be controlled by the type of powder processing technology used, as well as the sintering and melting conditions.

For example, plasma atomization produces high-quality powders that have more uniform dimensions and a narrower particle size distribution than traditional gas atomization techniques. These advantages make it easier for companies to achieve operational goals like meeting quality targets and minimizing downtime. The best way to do this is to use equipment that’s built for the job. This ensures that your machines work properly, and your operation runs smoothly.

Processes

The first step in the powder production process involves preparing raw metal. This includes blending, mixing, and grinding. The type of processing used will depend on the material being produced and its final use. The resulting powders can then be used in various ways, including injection molding and sintering.

The most common method for producing metal powders is gas atomization. This process uses high pressure gases or fluids to disperse a thin flow of melted alloy Powder Production Line into droplets that then rapidly solidify. The result is a fine, spherical powder with a high degree of purity and cleanliness.

In addition, a variety of chemical powder treatments can be used to enhance certain properties. For instance, oxide reduction can be used to produce low-melting powders with narrow particle size distributions and high purity. This method can also be used to produce amorphous powders, which have high pre-sinter strength and are easy to machine.

Plasma atomization is another popular metal powder production process. This technology produces very clean, spherical powders that are perfect for Additive Manufacturing. It has a high rate of throughput and is highly efficient. In addition, it can produce a range of different metals and alloys, including supersaturated solids, intermetallic compounds, and amorphous materials. It can even be used to make metal matrix composites. The process is environmentally friendly and generates very little waste. This makes it a cost-effective and environmentally sound alternative to traditional fabrication methods.

Properties

The physical properties of metal powders can have a significant impact on metallurgical production processes. These characteristics can be affected by the alloy composition, particle size and shape, morphology and surface chemistry. They can also be influenced by the handling, storage and gas used for further processing.

One of the biggest benefits of powdered metal is that it allows for greater precision and consistency in components. With superior net-shaping and tolerance adherence, a higher level of accuracy in parts is possible that reduces machining needs and leads to shorter production times with increased repeatability.

Another important property is the density of the powder. Bulk density is the ratio of the mass of the powder to the volume of the bulk, including the space between the particles. This can affect a wide range of powders’ functional properties, from flowability to sintering behavior.

The final quality of the powder is a combination of all the above factors and can only be realized with the right industrial gases. Linde offers a wide variety of gases, supply schemes and equipment to help producers achieve the best possible results in their powder production lines.

Applications

With the use of powder metallurgy, metal components can be made with greater accuracy and repeatability than those produced filling machinery using traditional ingot metallurgy. The metal alloys used in AM are processed into a fine, grain-like powder, which can then be used to build a part with laser sintering or other processes such as binder jetting and HIP (hot isostatic pressing). This allows the part producer to include features like reliefs, threads, undercuts and voids in the design of the component.

The metal powder must have a specific chemical analysis and size distribution to ensure that it is suitable for the process being used to make the component. Most powders have a range of major, minor and trace elements specified for each alloy type. The fact that there is no liquid phase in PM processing compared to ingot metallurgy has a significant impact on the microstructure and properties of the powders.

The AM machine user needs to know the powder supplier has a reliable production plant and a track record of consistent quality. It is also useful to understand the blending processes the powder manufacturer uses, and the criteria for combining heats into batches. This allows critical applications to be built with a blend of powders if one heat is out of specification. This can avoid problems when there is a build issue and prevents the use of unsuitable materials in the finished part.