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The paper presents the results of research studies involving the ceramic-metal tool materials with the deposited nitride coatings on the basis of aluminium, titanium and silicon. The cathodic arc evaporation with lateral rotating cathodes method was used for deposition of nanocrystalline, wear resistant nitride coatings – AlTiSiN type. Structural examinations are presented of the applied coatings and their support material made on the scanning electron microscope (SEM) and the scanning/transmission electron microscope (STEM). Chemical composition analysis as a function of the distance from the specimen surface, the so-called profile analysis, were carried out also. The structural analysis confirms that deposited multilayer coatings have dense microstructure without any visible porosity and delamination. It was found that the investigated coatings have nanocrystalline structure and consisting of fine crystallites even less than 6nm. Lattice deformations and numerous structural defects were also observed in the nanolayers. Depositing the AlTiSiN coatings results in the significant hardness increase within the range of 2252 ±256 to 2908 ±295 HV0.01.
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In the study, particle size distribution of the MIEX® resin was presented. Such analyses enable to determinate whether presence of fine resin fraction may be the reason for unfavorable membrane blocking during water purification by the hybrid MIEX®DOC – microfiltration/ultrafiltration systems. Granulometric analysis of resin grains using the laser diffraction particle size analyzer (laser granulometer) was carried out as well as the microscopic analysis with scanning electron microscope. The following samples were analyzed: samples of fresh resin (a fresh resin – not used in water treatment processes) and samples of repeatedly used/regenerated resin that were collected to analysis during mixing and after sedimentation process. Particle size distribution was slightly different for fresh resin and for repeatedly used/regenerated resin. The grains sizes of fresh resin reached approximately 60 μm (d10), 120 μm (d50) and 220 μm (d90). Whereas the sizes of repeatedly used/regenerated resin were about 15 μm (d10), 40 μm (d50) and 115-130 μm (d90). The smallest resin grains sizes were in the range of 0.3-0.45 μm. This ensures that the ultrafiltration membranes retain all resin grains, even the smallest ones. Whereas the microfiltration membranes must be appropriately selected to guarantee full separation of the resin grains and at the same time to exclude a membrane pores blocking.
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Mg60Zn35Ca5 amorphous powder alloys were synthesized by mechanical alloying (MA) technique. The results of the influence of high-energy ball-milling time on amorphization of the Mg60Zn35Ca5 elemental blend (intended for biomedical application) were presented in the study. The amorphization process was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM). Initial elemental powders were mechanically alloyed in a Spex 8000 high-energy ball mill at different milling times (from 3 to 24 h). Observation of the powder morphology after various stages of milling leads to the conclusion that with the increase of the milling time the size of the powder particles as well as the degree of aggregation change. The partially amorphous powders were obtained in the Mg60Zn35Ca5 alloy after milling for 13-18h. The results indicate that this technique is a powerful process for preparing Mg60Zn35Ca5 alloys with amorphous and nanocrystalline structure.
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