P.A. Lykov

Selective Laser Melting of Copper

In this work the selective laser melting (SLM) of pure copper powder was studied. Because of low laser radiation absorption and high thermal conductivity it is very difficult to organize stable SLM process for copper. Five 10x10x5 mm specimens were fabricated by using different process parameters (scanning speed, point distance, exposure time, scanning strategy). The structure of fabricated specimens was studied by scanning electron microscopy of polished cross-sections. The tensile test was carried out for SLM regime with the lowest porosity.

Composite Micropowders for Selective Laser Sintering

A method is proposed for obtaining composite micropowders. The technology includes the atomization of liquid metal by a gas jet and modification of the micropowder in a planetary mixer in the presence of carbon nanopowder. The particles of the composite micropowders produced by this method are close to spherical in shape. The fact that some parts of the particles’ surface are covered with graphite and some are not shows that it might be possible to obtain a sintered product which has adequate strength and a structure that contains carbon impregnations. The proposed technology makes it possible to produce a wide range of composite powders suitable for use in selective laser sintering.

Influence of SLM Process Parameters on Porosity of Nickel Base Heat Resistance Alloy EP648

In this research EP648 nickel base heat resistance alloy was used for Selective Laser Melting (SLM). This alloy can be used for producing details at high mechanical and thermal load by SLM for aerospace, automotive, shipbuilding and energy industries. To define the influence of SLM process parameters on EP648 4x4x4 mm cubic specimens were fabricated with different process parameters (scanning speed, laser power, layer thickness). The porosity of fabricated specimens was determined by scanning electron microscopy of polished cross-sections.

Influence of Powder Characteristics on Processability of AlSi12 Alloy Fabricated by Selective Laser Melting

Selective laser melting (SLM) is one of the additive manufacturing technologies that allows for the production of parts with complex shapes from either powder feedstock or from wires. Aluminum alloys have a great potential for use in SLM especially in automotive and aerospace fields. This paper studies the influence of starting powder characteristics on the processability of SLM fabricated AlSi12 alloy. Three different batches of gas atomized powders from different manufacturers were processed by SLM. The powders differ in particle size and its distribution, morphology and chemical composition. Cubic specimens (10 mm × 10 mm × 10 mm) were fabricated by SLM from the three different powder batches using optimized process parameters. The fabrication conditions were kept similar for the three powder batches. The influence of powder characteristics on porosity and microstructure of the obtained specimens were studied in detail. The SLM samples produced from the three different powder batches do not show any significant variations in their structural aspects. However, the microstructural aspects differ and the amount of porosity in these three specimens vary significantly. It shows that both the flowability of the powder and the apparent density have an influential role on the processability of AlSi12 SLM samples.

The Manufacturing of the AlSi12-Al2O3 Composite Powder for Additive Production Methods

The technology of composite micropowders’ obtaining that allows the production of a wide range of composite powders suitable for use in additive technologies is proposed. The technology includes modification of the metal powder surface with the mechanochemical treatment. The production modes for the AlSi12-Al2O3 composite powder are determined.

Parameter optimization for selective laser melting of TiAl6V4 alloy by CO2 laser

TiAl6V4 alloy is one of the widely used materials in powder bed fusion additive manufacturing technologies. In recent years selective laser melting (SLM) of TiAl6V4 alloy by fiber laser has been well studied, but SLM by CO2-lasers has not. SLM of TiAl6V4 powder by CO2-laser was studied in this paper. Nine 10×10×10 mm cubic specimens were fabricated using different SLM process parameters. All of the fabricated specimens have a good dense structure and a good surface finish quality without dimensional distortion. The lowest porosity that was achieved was about 0.5%.

Gas Atomization of the Liquid 82N7HSR Nickel Base Alloy to Produce Micropowder for Additive and Coating Technologies

In this paper an atomization of the Ni-based alloy 82N7HSR in a gas jet was studied. During the series of experiments different combinations of 3 main technological parameters (melting temperature, type of spraying gas, gas pressure in the spray nozzle) were considered. The size and shape of powder particles were studied by scanning electron microscopy and the optical granulomorphometer Occhio 500nano. The suitability of obtained powders 82N7HSR for usage in additive technologies and coating technologies was estimated.