By NANOTRUN | 20 July 2021 | 0 Comments
Metal Powders for 3D Printing: Characteristics, Production, Processing, and Applications
Metal Powders for 3D Printing: Characteristics, Production, Processing, and Applications
3D Printing powders are metals that are reduced to fine particles and are the preliminary base materials for most 3D printing processes that produce metallic parts. 3D printing, also known as additive manufacturing (AM), is the manufacturing of parts and products in a layer-by-layer fashion. Both the characteristics of the 3D Printing powder and the type of the 3D printing process determine the properties of the end product. Powder characterization takes place depending on the way it is produced, which may result in different particle morphology and purity.
Here, you can learn about what characterizes metal powders, how they are produced, and what 3D printing methods and applications employ such powders.
Characteristics of metal powders
To guarantee accurate reproducibility in metal component production, metal powders have to display consistent characteristics. The primary characteristics are size distribution and morphology. Other technological and Physico-chemical characteristics include density, compressibility, sintering ability, chemical composition, green strength, surface area, flowability, and thermal properties.
One of the main assumptions for 3D printing powder is that they are nominally spherical and have a certain size distribution that allows them to be well packed, which results in a dense product with good and desired mechanical properties. In other words, the particle size – which determines the smallest possible layer height to achieve – and particle shape, in addition to the powder’s level of purity, play a crucial role in controlling the powder quality.
Production of metal powders for 3D printing
To produce metal 3D Printing powders with the desired characteristics and powder quality and depending on the required properties of the metallic components to be manufactured from the powder, the selection of the powder production process may differ.
Metal powders can be produced using several methods, some of which are solid-state reduction, milling, electrolysis, chemical processes, and atomization. Yet, because it produces the most geometrically convenient powders for 3D printing, atomization has been historically regarded as the best method for producing metal powders for AM.
Atomization can be performed through, but not limited to, three different processes: water atomization, gas atomization, and plasma atomization. Water atomization, however, results in particles with a highly irregular morphology as the particles solidify faster than their periodization time, which renders the process not suitable for specialized AM.
Gas Atomisation
In this process, the feedstock alloy, usually in ingot form, is melted in a furnace; usually, a vacuum-induced melting (VIM) furnace monitors interstitial elements. The furnace is positioned above the atomization chamber for direct material discharge into the atomizer. As the melt falls down through the chamber, high-pressure gas jets are sprayed to atomize the material, which solidifies as spherical powder particles, and is collected at the bottom. The gas medium used is usually an inert gas, such as nitrogen or argon, to minimize oxidation and contamination possibilities. Air could also be used as a gas medium. The particle size distribution (0-500 μm) can be modulated to a certain extent by adjusting the ratio of gas to melt flow rate. Some of the powder materials produced by gas atomization are nickel, iron, aluminum, and cobalt.
When processing reactive alloys, like Ti-6Al-4V, there is a high contamination risk if the material gets exposed to the atmosphere or crucible. One way to reduce that risk is by introducing the metal into the atomizer as a rod, melted by a surrounding induction coil prior to entry. This method is called electrode induction melting gas atomization (EIGA).
Plasma Atomisation
Here, the feedstock is fed into the atomization chamber in two possible forms, wire or powder form. In the chamber, co-axial plasma torches and gas jets melt and atomize the material at the same time, resulting in extremely spherical powder particles with a relatively finer size distribution (0-200 μm). Titanium is commonly produced by plasma atomization.
A more specialized method called plasma rotating electrode process (PREP) makes use of a rotating bar instead of a wire as the feed form, whereupon entry to the atomization chamber, the bar extremity is melted by the plasma torches, and the discharged melt solidifies before reaching the encompassing walls. This process results in powders of high purity, high sphericity, and fine particle sizes (0-100 μm). Titanium and exotic materials can be produced by PREP.
3D Printing Powder Supplier
TRUNNANO (aka. Luoyang Tongrun Nano Technology Co. Ltd.) is a trusted global chemical material supplier & manufacturer with over 12 years' experience in providing super high-quality chemicals and Nanomaterials. Currently, our company has successfully developed a series of materials. The 3D Printing Powder produced by our company has high purity, fine particle size and impurity content. Send us an email or click on the needed products to send an inquiry.
3D Printing powders are metals that are reduced to fine particles and are the preliminary base materials for most 3D printing processes that produce metallic parts. 3D printing, also known as additive manufacturing (AM), is the manufacturing of parts and products in a layer-by-layer fashion. Both the characteristics of the 3D Printing powder and the type of the 3D printing process determine the properties of the end product. Powder characterization takes place depending on the way it is produced, which may result in different particle morphology and purity.
Here, you can learn about what characterizes metal powders, how they are produced, and what 3D printing methods and applications employ such powders.
Characteristics of metal powders
To guarantee accurate reproducibility in metal component production, metal powders have to display consistent characteristics. The primary characteristics are size distribution and morphology. Other technological and Physico-chemical characteristics include density, compressibility, sintering ability, chemical composition, green strength, surface area, flowability, and thermal properties.
One of the main assumptions for 3D printing powder is that they are nominally spherical and have a certain size distribution that allows them to be well packed, which results in a dense product with good and desired mechanical properties. In other words, the particle size – which determines the smallest possible layer height to achieve – and particle shape, in addition to the powder’s level of purity, play a crucial role in controlling the powder quality.
Production of metal powders for 3D printing
To produce metal 3D Printing powders with the desired characteristics and powder quality and depending on the required properties of the metallic components to be manufactured from the powder, the selection of the powder production process may differ.
Metal powders can be produced using several methods, some of which are solid-state reduction, milling, electrolysis, chemical processes, and atomization. Yet, because it produces the most geometrically convenient powders for 3D printing, atomization has been historically regarded as the best method for producing metal powders for AM.
Atomization can be performed through, but not limited to, three different processes: water atomization, gas atomization, and plasma atomization. Water atomization, however, results in particles with a highly irregular morphology as the particles solidify faster than their periodization time, which renders the process not suitable for specialized AM.
Gas Atomisation
In this process, the feedstock alloy, usually in ingot form, is melted in a furnace; usually, a vacuum-induced melting (VIM) furnace monitors interstitial elements. The furnace is positioned above the atomization chamber for direct material discharge into the atomizer. As the melt falls down through the chamber, high-pressure gas jets are sprayed to atomize the material, which solidifies as spherical powder particles, and is collected at the bottom. The gas medium used is usually an inert gas, such as nitrogen or argon, to minimize oxidation and contamination possibilities. Air could also be used as a gas medium. The particle size distribution (0-500 μm) can be modulated to a certain extent by adjusting the ratio of gas to melt flow rate. Some of the powder materials produced by gas atomization are nickel, iron, aluminum, and cobalt.
When processing reactive alloys, like Ti-6Al-4V, there is a high contamination risk if the material gets exposed to the atmosphere or crucible. One way to reduce that risk is by introducing the metal into the atomizer as a rod, melted by a surrounding induction coil prior to entry. This method is called electrode induction melting gas atomization (EIGA).
Plasma Atomisation
Here, the feedstock is fed into the atomization chamber in two possible forms, wire or powder form. In the chamber, co-axial plasma torches and gas jets melt and atomize the material at the same time, resulting in extremely spherical powder particles with a relatively finer size distribution (0-200 μm). Titanium is commonly produced by plasma atomization.
A more specialized method called plasma rotating electrode process (PREP) makes use of a rotating bar instead of a wire as the feed form, whereupon entry to the atomization chamber, the bar extremity is melted by the plasma torches, and the discharged melt solidifies before reaching the encompassing walls. This process results in powders of high purity, high sphericity, and fine particle sizes (0-100 μm). Titanium and exotic materials can be produced by PREP.
3D Printing Powder Supplier
TRUNNANO (aka. Luoyang Tongrun Nano Technology Co. Ltd.) is a trusted global chemical material supplier & manufacturer with over 12 years' experience in providing super high-quality chemicals and Nanomaterials. Currently, our company has successfully developed a series of materials. The 3D Printing Powder produced by our company has high purity, fine particle size and impurity content. Send us an email or click on the needed products to send an inquiry.
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