Metal powder production of non-reactive materials

Recent market studies show a two-digit growth for metal powder consuming manufacturing technologies such as additive manufacturing or coating. Thus, expectations for availability and constant quality of metal powders are increasing. The company qualloy is addressing these market demands by offering buyers to find the needed powder based on their machine specifications.

Powder production

Different technologies for the production of metal powders were introduced to the market in recent years. The majority of non-reactive metal powders are produced by gas atomization.

To realize highest cleanness of the powder, the melting and refining of metals and alloys takes place under vacuum or inert gas atmosphere. The atomizing process with argon or nitrogen guarantees defined grain sizes and distribution of metal powders.

In a powder atomization plant, the raw material is melted in an induction furnace under vacuum or an inert gas atmosphere. The molten material usually flows through a tundish into the atomization unit. The atomization is done by the close-coupled nozzle. During the process grain sizes between 0 and 300 µm are achieved. To control and optimize the yield in desired particle fractions the control of the gas-to-metal ratio is mandatory. The process has a direct influence on the quality of the powder, e.g. on the oxygen content or the morphology of the particles.

Principle behind metal powder production

The basic principle behind metal powder production is the transfer of kinetic energy from a high-speed gas jet to a liquid metal stream. With free-fall atomization, the molten stream is disintegrated by a secondary jet about 100–300 mm below the primary nozzle whereas with close-coupled atomization plants, both nozzles are at roughly the same height.

Liquid metal is superheated in a storage tank, e.g. an inductively heated tundish, flows through a primary nozzle and is atomized by a high-pressure inert gas jet. The gas jet exits the coaxial secondary nozzle typically in an under-expanded state. The primary atomization zone is characterized by the disintegration of the metal stream as a result of the severe pressure drop directly below the nozzle system; this is where the metal stream becomes unstable and deformed and disintegrates into ligaments and droplets.The secondary atomization zone is characterized by the progressive breakup of large, unstable droplets into tiny, stable droplets. The droplets exit the atomization zone, sink downward, driven by gravity and supported by the gas flow, cool down and form the raw powder.

The startup qualloy simplifies the powder market. Sellers and buyers meet on their digital platform environment. The sourcing and selling process is significantly simplified for both buyers and sellers. Through the intelligent search algorithm, the user finds the powder for his printer and specification in the shortest possible time and can choose between different certified manufacturers in terms of quality, price and delivery time. Each user always finds his powder at the optimal price and delivery time with constant quality. This ecosystem allows switching freely between different powder manufacturers. If a powder has the same property profile, it can be purchased from different manufacturers without adjusting the process parameters. For the powders, qualloy gives a quality promise.

Conclusion

The basics of powder production using a close-couple-nozzle is presented in this article. The complexity of production and possibly unstable powder quality lead to a complex market situation. The complexity and intransparency leads to apparent dependencies and hurdles when changing powder producers. This often results in unreasonable powder prices. qualloy simplifies the market and opens up new possibilities for users to source high-quality powder for their requirements easily and at fair prices.