Crystalline 4- to 5-nm gold nanoparticles supported on graphite and oxidized silicon have been obtained by the impregnation method. Specific features of the adsorption and interaction of H2 and O2on...

This review discusses the main methods for producing spherical powder particles of corrosion-resistant steels as a material widely used in all industries. Also the examples of products made by modern additive methods are described. Currently, spherical powder particles of corrosion-resistant steels are used in the following additive methods: selective laser melting, selective laser sintering, direct laser sintering, and electron beam melting. Each of these methods has its own requirements for the characteristics of spherical powder particles of corrosion-resistant steels. The review provides a brief description of the principles of operation of each method and the requirements for spherical powder particles of corrosion-resistant steels. It also considers a detailed description of each method of additive manufacturing with a description of the principle of operation and specific examples of obtaining spherical particles of corrosion-resistant steel powders with indication of their properties (morphology, structural features, chemical composition, fluidity, bulk density). A comparative analysis was carried out with a description of disadvantages and advantages of each method. Examples of the use of spherical particles of corrosion-resistant steel powders for the manufacture of products by various additive methods (including post-processing) are given with description of the final products characteristics. Based on the data presented, a conclusion was made about the preferred methods for obtaining spherical particles of corrosion-resistant steel powders for specific additive methods used in modern industry. The review considers the following methods for producing spherical powder particles: water atomization (atomization of liquid metal with a jet of water under pressure); gas atomization (atomization of the melt with a jet of inert gas (argon or nitrogen) under pressure); centrifugal atomization (atomization of molten metal with a high-speed rotating disc); ultrasonic atomization (atomization of liquid metal by ultrasound); non-contact atomization (atomization of liquid metal with a powerful pulse of electric current); plasma wire spraying; plasma spraying of a rotating electrode; plasma spheroidization.

The physicochemical properties of nanoparticles (NPs) of aluminum, gold, nickel, and platinum have been determined by methods of scanning tunneling microscopy and spectroscopy, Auger spectroscopy, and mass spectrometry. The geometric sizes, electronic structure, and surface chemical composition of the NPs have been established. The adsorption heat and the effective activation energy have been determined using the example of the interaction between hydrogen and gold, nickel, and platinum NPs.