Politechnika Warszawska, Wydział Inżynierii Lądowej, Warszawa
PREMIX Sp. z o.o., Połaniec
Contemporary trends in development of technology of mineral binders are oriented in particular to the search for materials with a reduced negative environmental impact, while obtaining not worsened performance characteristics and durability. A common approach includes modification by introducing conventional non-clinker additives. However the main direction of development of cement technology is the search for new materials of chemical base similar to clinker raw materials, but not yet used. This article presents selected trends of currently conducted research in the field of mineral building binders and selected topics related with geopolymer binders production. The basic properties of geopolymer binders and also the perspectives of its applications in building applications have been presented.
Keywords: geopolymer, composites, properties
2018, Vol. 61, nr 3, pp.57-61
Opole University of Technology, Department of Materials Engineering, Faculty of Mechanical Engineering, Poland
Metsä Tissue, Krapkowice, Poland
The paper presents test results of the oxidation of P265 steel, taking into account the effect of the surface roughness. Isothermal oxidation was carried out in air in the temperature of 800 ˚C during 1, 5, 20 and 25 hours. It was found that the surface condition which was directly linked to the surface preparation is crucial for the adherence between the substrate and the scale, and the structure of the oxidation products layer.
Keywords: oxidation, surface roughness, P265steel
2018, Vol. 61, nr 3, pp.62-65
Department of Chemistry, Częstochowa University of Technology
Al. Armii Krajowej 19, 42-200 Częstochowa, Poland
Institute of Materials Science and Engineering, Łódź University of Technology
The effect of encapsulation of LaNi4.5Co0.5 hydrogen storage powdered material, with thin magnetron sputtered layer of SiC, on basic hydrogenation parameters of the composite hydride electrode has been discussed. The multicycle galvanostatic charge/discharge method allowed to determine electrode hydride capacity, exchange current density of the H2O/H2 system, and evaluate material tendency to corrosion degradation. The electrochemical diagnostic experiments carried out at room temperature, at charge/discharge rates of −186/+186 mA g−1, revealed the initial discharge capacities on the level of 289 mA h g−1 for the tested electrodes. The presence of SiC layers on hydride powder improves kinetics of hydrogen electrosorption process.
Keywords: Hydrogen storage alloy, corrosion degradation, SiC coating, relative capacity, electrosorption kinetics
2018, Vol. 61, nr 3, pp.66-69
Institute of Precision Mechanics, Warsaw, Poland
The paper presents results of studies of nanocrystalline nickel/graphene (Ni/graphene) composite layers produced by electrocrystallization method on steel substrate. Several variants of Ni/ graphene layers were realized using a bath with different graphene content and for comparison purposes a nanocrystalline nickel layer was also produced. Graphene flakes dispersed in the bath were used as a dispersion phase. The dispersed phase was characterized by Raman spectroscopy and scanning (SEM) and transmission (TEM) electron microscopes. The results of investigations of the structure of the produced layers with SEM, results of Vickers hardness measurements and results of corrosion tests using electrochemical potentiodynamic method are presented. Damage characteristics after corrosion studies were obtained using a light microscope.
Electrochemically deposited Ni/graphene composite layers are characterized by higher hardness and better corrosion resistance than the nickel layer without built-in graphene.
Keywords: graphene, layers of Ni, composites of Ni/graphene, electrocrystallization, corrosion resistance
2018, Vol. 61, nr 3, pp.70-73
CORROSION PROTECTION IN PRACTICE
Instytut Techniki Budowlanej, Warszawa
The testing procedure for powder coatings for which the manufacturer intends to have the license quality label QUALICOAT is described. The research processes including: preparation of samples, the measurements of physical properties and testing of coatings resistance to chemical agents and climatic conditions have been presented. Particular attention was paid to the Florida test due to its organization, implementation and requirements. This paper does not apply to conducting a formal procedure by the paint manufacturers before deciding on the implementation of the laboratory test procedure.
Keywords: powder coatings, aluminum for architectural application, laboratory tests, Florida test
2018, Vol. 61, nr 3, pp.75-77