Modeling of protective plasma spray ceramic coating made of clad powder mixture

To solve the problem of increasing the adhesive-cohesive strength of plasma multifunctional coatings used to protect parts of power and mechanical engineering equipment components from wear and corrosion, a ceramic coating of the “Al2O3 - Ni” system, obtained from a powder mixture based on corundum clad with nickel, is proposed for use and studied. The coating was applied by high-energy plasma powder deposition (on the “Thermoplasma-50” installation) to the intermetallic sublayer of the “Ni-Co-Cr-Al-Y” system. The aim of this work was to study the micro structure and phase composition of the powder mixture of oxide ceramics clad with a refractory metal component (nickel), as well as the plasma coating formed from this powder material. According to the results of the research, it was found that the powder mixture clad with nickel has a multiphase composition (Ni+l-Al2O3+r-Al2O3), a spherical morphology of particles. From this powder material, a coating with a phase composition (Ni+L -Al2O3+J ’-L J u Ll) is formed, characterized by a layered microstructure with a columnar structure of oxide grains and nickel interlayers. The coating has high hardness and adhesive-cohesive strength, low coefficient of friction and is recommended for protection against wear of energy and mechanical engineering parts.

Effect of Fullerenes Additions on Physical – Mechanical Properties of Hot-Forged Iron-Based Powder Materials

It is possible to expand the applications ranges of powder material products by enhancing the performance properties of these products in addition to their manufacturability and reliability together, it’s possible by materials structures modification. In this paper, the effect of fullerene (C60) additives to iron-based powder material has been studied. All samples produced by Hot-Forging (HF) powder materials technology. Green and HF density of the obtained samples calculated by volume / weight and Archimede’s principle, respectively. The effect of technological parameters on the microstructure of carbon steels’ samples was done by an ALTAMI MET-1M metallographic microscope. Tensile test executed by using of a universal testing machine UMM –5 and the microhardness (HV10) was measured by REICHERT hardness test machine. The results showed that the HF C60 steels’ samples had higher density and strength of 0.81 and 25%, respectively, with a good plasticity in comparison with graphite steels’ samples.

Investigation of the effect of HIP processing on the physical and mechanical characteristics of parts obtained by the SLM method

In this paper presents the results of studying the powder material AISI 321. Selective laser melting (SLM) of the samples was carried out in modes with a change in the radiation power. The subsequent processing of the samples by the method of hot isostatic pressing (HIP) was carried out. The roughness of the surfaces and the microhardness of the samples before and after the HIP were studied.

Effect of tungsten nanoparticles on sintering of the Sn-Cu-Co-W powder material

The effect of tungsten nanoparticles on the kinetics of sintering of the Sn-Cu-Co-W powder material used as a binder in diamond tools was studied. The W16,5 grade tungsten powder was mechanically activated in the AGO-2U planetary centrifugal mill for 60 minutes at the carrier rotation frequencies of 800 RPM. The mixture of tungsten, tin, copper, and cobalt powders was compacted by static pressing in press dies and then sintered in vacuum at the temperature of 820°C. The morphology and sizes of powder particles, as well as the structure of the sintered samples, were studied by the methods of scanning electronic microscopy. It has been demonstrated that tungsten nanoparticles have a noticeable effect on the process of dissolution-reprecipitation of cobalt in liquid-phase sintering.

Simulation of the kinematics and gas dynamics of the centrifugal dispersion stand

The article studies the kinematics and gas dynamics of the centrifugal dispersion stand for spheroidizing hard alloy materials. When studying the process of centrifugal spraying on an experimental setup, it was found that the behavior of particles in the volume of the dispersion chamber is determined by the aerodynamics of gas flows formed in the working chamber. It is assumed that under the influence of gas flows, a spontaneous classification of the particles of the medium occurs, determined by the size of the latter. To study the trajectory of movement of particles of powder material in the working chamber and the deposition process, a gas-dynamic model of a centrifugal dispersion unit in the SolidWorks FlowSimulation application is proposed. The developed model of the centrifugal dispersion unit showed the possibility of operational analysis of the behavior of the gas flow, the trajectory of the particles of the powder material and the temperature of the obtained powder material, depending on the design and technological factors. The simulation results allow one to determine the principles of separation of a heterogeneous medium of particles into fractions, directly at the installation for the implementation of the method.

Liquid Migration in the Paste as the Result of Consolidation

The processing of various powder materials is often done by an extrusion process; the powders being formed into a paste by the addition of a liquid substance. During extrusion, by reason of the extrusion pressure, some properties of the paste are changing, which affect its rheology and thus the extrusion itself. One of the phenomena is the movement of the liquid phase. This paper is focused on monitoring this phenomenon using model material in a simple test device. Its design simulates the effect of pressure in the extruder. The results of the measurements provide a picture of the movement of the liquid phase under the influence of the pressure in the porous skeleton formed by the powder material.

The model of potential barrier appearing in a hydrolayer localized in a two-layer porous nanostructure

A model has been proposed to describe the potential barrier that appears during interaction of two compacted layers consisting of hydrophilic oxide nanoparticles of different sizes in each layer upon saturation of this structure with adsorbed water. The dependence of the space charge density of the compacted powder material on the density of particles in it has been theoretically calculated. The distribution of the potential over the thickness of contact between two layers consisting of nanoparticles with different sizes has been obtained.