Wyniki 1-2 spośród 2 dla zapytania: authorDesc:"Wojciech Bartoszek"

Corrosion properties of Ni-B/Al2O3 composites layers produced by electroless method DOI:10.15199/40.2017.7.1

  1. Introduction The rapid development of technology forces the search of new materials with more favorable mechanical and physical properties and corrosion resistance. Furthermore, due to restrictions on the use of such materials as chrome and cadmium there is a sought of alternatives much less toxic to humans and more protecting the environment, with meeting at the same time the high performance requirements. An important place in surface engineering is assigned to the surface layers deposited by electroless method. Improvement of the properties of materials by deposition on their surfaces of the metal layers by electroless methods has been known for a long time and still further is under developements. Especially interesting in this subject appears the production of composite materials whose properties significantly depend on the structure of the matrix material and of the disperse phase. The literature describes studies of Ni-P, Ni-B layers [2, 11, 7, 1] and composite materials deposited in the form of the surface layers by electroless method [10, 5, 8, 9, 6], which significantly increase the life of the pieces’ work, including the corrosion resistance. 2. Research methodology Composite layers of Ni-B/Al2O3 and alloy Ni-B layer were produced by electroless method on the DC01 carbon steel substrate. The deposition process was carried out in multicomponent bath containing: nickel chloride, sodium borohydride, ethylenediamine, sodiumhydroxide and leadnitrate. As the dispersion phase was used o powder of aluminum oxide (TAIMEI CHEMICALS co., ltd.) with its content in the bath of 5 and 10 g/dm3. Powder of Al2O3 was characterized by scanning electron microscopy (ZEISS) and X-Ray diffraction (Philips). The morphology and topography of produced layers were analyzed using a VHX 5000 Keyence optical microscope. The microhardness of the layers was examined on the probe cross-sections by the Vickers method at 25 G load (HV 0.025) [...]

Corrosion properties of Ni/Al2O3/Cgraphite hybrid composite layers DOI:10.15199/40.2018.2.2

  1. Introduction The requirements for mechanical properties and corrosion resistance of equipment components working in modern constructions are continuously increasing. To improve the performance of the final products, their surfer layers are effectivelly modified. One of the methods of modifying the useful properties of the products is the deposition of appropriate metal layer on their surface by electrodeposition method. The properties of electrodeposited layers can be formed by suitable selection of electrolyte solution composition and by current parameters control. It has to be noted that presently the composites layers made of metal matrix and dispersion phase are increasingly used in many industries. The matrix material and type of dispersion phase - especially size of particles and their percentage share in the material affect the composite layer properties. By appropriate selection of matrix material and type of dispersion phase, properties of the produced composite layers can be controlled [4, 5, 8, 9]. The new direction of concerned research is the incorporation of two types of dispersion phase into metal matrix, resulting in a hybrid layer. Production of this type of layers allows to apply dispersion phases with different properties like hard particles of Al2O3, Si3N4 or PTFE and graphite particles which improve lubricating properties [1, 6, 7]. A material with high abrasion resistance and lubricating properties what is desirable in the friction nodes can be made by appropriate selection of size and shape of particles and percentage share of both incorporated phases. The subject of realized research are hybrid composite layers Ni/Al2O3/ Cgraphite and composite layers Ni/Al2O3, Ni/Cgraphite which are made for comparative purposes. Nanostructure nickel layers made by electrodeposition method were also investigated. The purpose of the performed study was to determine the influence of incorporation of two types of dispersio[...]

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