Thanks to its internal laboratory, equipped with advanced technologies and highly specialized technicians, LEGOR GROUP endorses its Clients in the development of the production processes, to guarantee superior quality results for the making of custom additive manufacturing powders.

Technological Properties Analysis

  • Particles Morphology and Size Distribution

    Particles morphology describes the geometric shape of the particles and it highly depends on the productive technology adopted (atomization, grinding, electrochemical processes, etc.).

    When dealing with Additive Manufacturing technology a strong preference goes to powders obtained through gas-atomizing processes, because they allow to obtain highly spherical particles.

    Particles morphology can be observed using a Scanning Electron Microscope (SEM); this high-magnification laboratory microscope allows to investigate the geometric properties of the powder such as quantify its roundness and observe the possible presence of defects (particles clusters, satellites, empty particles, etc.).

    In case of highly spherical powders, every single powder particle can be assimilated to a perfect sphere of which we can measure the diameter. The particles size distribution are usually measure by means of a Laser Diffraction Analyzer that uses a laser beam and advanced mathematical algorithm in order to calculate the particles size distribution, the mean particles diameter and other geometrical parameters useful for characterized the powder. The typical powders size distribution for Additive Manufacturing application is unimodal with a grain size between 10 and 45 micron but other particles size range could be adopted in function of the specific process, machine, material and final application.

    Powders morphology and size distribution are very important technological parameters because they contribute to define the powder flowability, therefore its layering capability (e.g. the easiness of being layered). Determination of particle size profile of the powders can be useful as quality control for new materials or for monitoring material feedstock after powders recovery.

  • Flowability

    Powders characterized with a high flowability give better results, in terms of homogeneity and repeatability, during the layer formation; this means that high flowability powders can reduce the presence of defects in the final built object.

    The particles shape influences the flowability and is therefore an important properties during the deposition of a layer. Particles with a spherical shape flow better that irregular particles, such as, course particles with a narrow size distribution flow better than fine particles with wide size range. Fine particles has also the tendency to create agglomerates reducing in this way the ability to flow. Anyway, flowability cannot be considered a direct property of the material since it results both from the material’s physical properties but also from some external factors as the system adopted to measure it, material density, friction, surface area, moisture, etc.

    Flowability is usually measure using a special funnel having a calibrate orifice called Hall Flowmeter and expressed as sec/50g; other method keep in account the compressibility (ratio between Tap Density and Apparent Density) of the powder as an indicator of its tendency to flow (Hausner ratio and Carr index). Determination of flowability of powders can be useful for quality control in case of new material or for monitoring material feedstock after powders recovery.

  • Apparent density

    Apparent density defines the grams of loose powders within a stated volume, it is measured through careful analysis and is expressed as g/cm3.

    The apparent density is strongly affected by particles size but other powders characteristics such as metal density, particles morphology, surface area and so on, must be considered. Apparent density generally decrease when present an high fraction of fine particles such as when the particles shape becomes less spherical and more irregular.

    For Additive Manufacturing powders, with unimodal distribution and high spherical shape, the free-flow apparent density is about 45-60% of the bulk material density.

    Determination of apparent density of powders can be useful as quality control for new materials bathes or for monitoring materials feedstock after powders recovery.

  • Tap density

    Tap density is defined as the powders density when the vessel, where the powders are placed, is vibrated (tapped) under a specific condition.

    Vibrational movements of loose powder induces lower friction between particles increasing the powder packaging; tap density is therefore higher in comparison to apparent density. Tap density is mainly correlated to the shape and size distribution of the particles.

    Tap density is measured using a graduate glass cylinder of appropriate capacity and accuracy; the cylinder is tapped by means of mechanical device at the rate of 200-300 taps per minute until the maximum powders packaging is achieved.

    Determination of tap density of powders can be useful as quality control incase of new materials batches or for monitoring feedstock powders after their recovery.

Chemical Properties Analysis

  • Chemical Composition (macro/micro elements and impurities)

    Determination of the chemical composition via wet method using emission spectroscopy with plasma torch (ICP-EOS). Analysis of both the macro-elements and impurities.

  • O/N analysis

    Determination by combustion analysis of chemical elements such as oxygen and nitrogen (data not obtainable by means of ICP-EOS).

  • C/S analysis

    Determination by combustion analysis of chemical elements such as carbon and sulfur (data not obtainable by means of ICP-EOS).

Physical Properties Analysis

  • Bulk Density

    Determination of the density of the sample using Archimedes' method.

  • Porosity

    Determination of the porosity distribution area of metallographic section of the specimen by processing images obtained by optical microscopy (LOM).

  • Melting Range

    Determination of the melting range of the material by means of differential thermal analysis (DTA).

  • Color Measurement

    Determining spectrometric CIELab color coordinates of metallographic section of the specimen.

  • Roughness

    Determination of roughness (eg value of Ra[m] Rz [m]) on the specimen. Possibility of testing in different conditions of surface finishing (eg: after blasting and / or shot peening).

  • Hardness and other Mechanical Tests

    Determination of the main mechanical characteristics of the material via pull test (eg: load at break, yield stress, elongation). Ability to run the test in different states metallurgical (eg after heat treatment).


Scanning electron microscope with microanalysis probe
Inductively coupled plasma optical emission spectrometer
Thermal and gravimetric analysis
Potentiometric determination of silver in compliace with the UNI EN 315337:1997 standard
Vickers microdurometer
Tensile test machine
Facilities for metallographic preparation
Metallographic microscopes
Colorimetric analyses
Elementary analysers
Determination of single elements (O, N, C, S)
Climatic chambers
Corrosion resistance tests
Laser granulometer
Determining of granulometric profile of powders


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