3D printing produces very little waste compared to traditional manufacturing methods that use material reduction. Also, the direct forming features of this manufacturing method reduces the amount of equipment needed in the production. Metal powder is used as the raw material in metal 3D-printing. Its properties have a strong relationship with the quality of final products. The main requirements for metal powder 3D-printing are chemical composition and particle shape. They also include particle size, particle distribution as well as fluidity.<br /><br />
chemical composition<br />
Impurities and metal elements are the most important chemical constituents of raw materials. Fe, Ti N, A Cu Co Cr and precious metals such as Ag, au are the most commonly used metal elements. Impurities can include Si (Mn), C, S, and P in reduced ferr, as well other impurities that are mixed with raw materials or powder production.<br />
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During the formative process, impurities could react with matrix and change its properties, resulting in negative effects to the product. Powders can melt unevenly when dopants are present, and this can cause defects in the product. The high oxygen content in powders can cause metal powders to not only oxidize easily and form oxide films but also spheroidize. This affects product density and quality.<br />
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It is therefore necessary to strictly monitor the impurities, doping and raw material powders in order to ensure the quality. For 3D printers, it is important to use metals powders that are high in purity.<br /><br />
Particle Size and Distribution, Particle Shape<br />
1.Shape requirements. Common shapes are spherical and subspherical particles, as well as flaky, irregular, and needle shapes. Irregular shaped particles have more surface area and this is conducive to sintering. The powder with a high degree of sphericity, however, has a good flow and uniform powder feed which can improve the density and consistency of the final product. For 3D printing, powder particles are required to be spherical.<br />
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Particle size and particle distribution of powders. The results reveal that the powders melt by absorbing directly the energy of the laser or the electron East scanning. The more energy is absorbed by the particles, the smaller they are, and higher temperatures promote sintering. Additionally, powders with a small size have fewer gaps between them, a high loose density and a high density of the parts after they are formed. This is conducive to increasing the strength of products and improving their surface quality. The powder will tend to agglomerate if the particle size is small. This can affect the uniformity and transportation of powder.<br />
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For the best forming effects, the fine powder and coarsen powder should be mixed together in a specific proportion. The particle size and distribution of particles should also be chosen carefully.<br /><br />
Requirements on the Processing Performance of Powder<br />
The technical properties of powders includes bulk density and compacting density. Fluidity, recycling performance, and recycling ability are also included.<br />
1. When powder is naturally accumulated, it’s loose packing density. Vibrating densities are the densities after vibration. Powders with high bulk density, low porosity are produced by powders that have good spheres and a wide particle distribution. The parts formed from these powders will also be dense and of good quality.<br />
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2. Liquidity. The fluidity affects powder uniformity, or stability in powder feeding. A powder with poor fluidity will result in an uneven layer thickness, uneven melting in the scanning zone and a poor forming of the product. Powders with high fluidity are easy to fluidize and deposit evenly, while the powder usage rate is high. These factors contribute to the improvement of dimensional accuracy, surface consistency, and compactness for 3D-printed parts.<br />
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3. Cyclic performance. The powder in the bed that was not melted after 3D printing is still usable and can be recovered by screening. Under long-term temperatures above 100°C, however, the powder will change its performance.<br />
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Tech Co., Ltd., a stainless steel powder manufacturer, has over 12 years of experience in research and product development. You can contact us by sending an inquiry if you are interested in high quality Metal Stainless Steel Metal Powder.<br />
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