Dagmar Jakubéczyová

Surface analysis of polymeric substrates used for inkjet printing technology

Purpose – This paper aims to find an optimal surface treatment of commonly used polymeric substrates for achieve the high adhesion of printed structures. For this reason, the investigation of substrates surfaces from different perspectives is presented in this paper. Design/methodology/approach – The contact angle measurements as well as the roughness measurements were realised for the analysis of surface properties of investigated substrates. The impact of applied chemical agents for surface treatment onto the wettability is analysed for polyimide, polyethylene terephthalate and polyethylene naphthalene substrates. Findings – The results prove the correlation among wettability, surface energy and work of adhesion with respect to the theoretical background. The surface treatment of polymeric substrates by chemical agents, such as acetone, toluene, ethanol, isopropyl and fluor silane polymer, has a significant impact onto the wettability of substrates which affects the final deposition process of nanoinks....

Investigation of nano-inks’ behaviour on flexible and rigid substrates under various conditions

Purpose This paper aims to find the optimal deposition conditions for achieving the homogenous structure of the silver layers onto three types of polymeric substrates as well as on the rigid substrates. For this reason, the detailed investigation of the silver-based layers deposited at different technological conditions by microscopic methods is presented in this paper. Design/methodology/approach The special test pattern has been designed and deposited at different substrate temperatures by using two types of generally available silver-based nano-inks. Cross-sections and 3D profiles of the deposited silver layers have been profoundly analysed by using the optical profiler Sensofar S Neox on the generally used polymeric (PI, PET and PEN) and rigid substrates (951 and 9K7 LTCC, glass and alumina). Findings The results prove the strong correlation between the substrate temperature during the deposition process and the final shape of the created structure which has the a direct impact on the layers’ homogeneity. The results also prove the theory of the coffee ring effect creation in the inkjet printing technology. Originality/value The main benefit of this paper lies in the possibility of the homogeneity achievement of the deposited silver-based layers on the several polymeric and rigid substrates by managing the temperature during the deposition. The paper also offers the comparative study of nano-inks’ behaviour on several polymeric and rigid substrates.

The Research of the High Speed Steels Produced by Powder and Casting Metallurgy from the View of Tool Cutting Life

High speed steels have a leading position in the group of tool materials today in regard to their special properties. The article deals with the cutting life of tools, which cutting tips were produced from high speed steels. The test were realized at Faculty of Manufacturing Technologies TU Kosice with the seat in Presov, in collaboration with Institute of Material Research of Slovak Academy of Sciences in Kosice. As the method for tool-life investigation was selected the simple radial lathe-turning test. The measured values were statistically processed and submitted to the remoteness testing according to Grubbs. The results of the experiments are graphically presented as a dependence of cutting life on the cutting speed for five types of high speed steels. The base material for four of them was high speed steel STN 19 830 produced via powder metallurgy. It was modified by additional alloying elements, so in this way originated next variations of this steel listed above. Measured data were compared with the fifth type of high speed steel with similar chemical composition, but this type was produced via classical approach - by casting metallurgy. The know-how of the investigated relation will enable to the producers to make a good decision about what type of tool material should be used at the machining in specific conditions in order to achieve good quality of machined surface while achieving the required level of energy consumption.

Mechanical and Tribological Characteristics of Sintered Manganese Steels

The effect of three iron powder grades and three manganese carrier types on mechanical and tribological characteristics of sintered 1 -5% Mn steels was investigated. The different effect of iron powder grades in dependence on manganese addition expressed oneself in strength and in wear. The highest strength and highest wear attained the steels with 3% Mn added as high carbon ferromanganese. The components – rollers - prepared from manganese steel exhibited lower wear than that from Fe-4Ni-1.5Cu-0.5Mo powder. The gears for hydrogenerator prepared from Fe-3.5Mn-0.5Mo-0.3C steel exhibited longer life time at increased oil pressure compared with that from through hardened sintered Fe-4Ni-1C steel.

Quality Evaluation of the Coatings and Its Influence on the Wood Machining Tool Wear

Coating of the tools for metal machining has been used for a long time, application of the coating to wood machining tools is not so explored. The aim of research in this area is to expand the possibilities of the using of PVD coatings in untraditional field at wood wool production in company, that thermo isolation and sound isolation plates manufactures. In the production of wood fibers by technology like planning, during the work the cutting edge of the knife is worn-down and the resulting product loses quality. Often grinding is required, knife dimensions are changed and lose its functional surface. The article is focused on the choose of the coating type on the base of input analysis of the tool material. Analysis is aimed to detection of the chemical content of elements, evaluation of the microstructure and mechanical properties. On the basis of the results, we proposed the type of coating applied to the sample and the tool. Coated sample was evaluated in terms of coating properties namely the thickness, tribological properties, chemical composition (EDX analysis) and microhardness. After the experiment, we have evaluated the state of cutting edge and compared it with the uncoated tool. The positive effect of the coating on the change of the cutting properties of the knife and the quality of the wood wool have been recorded.

The Analyse of Nanocomposite Thin Coatings Using Specimens Prepared by Focused Ion Beam Milling

The microstructure of physical vapour deposition (PVD) coatings deposited by duplex technology was investigated by Dual Beam FIB/SEM system (focused ion beam / scanning electron microscope), which allows one to examine cross sections of specimens from their surface down to the substrate. Examined were PVD coatings of nanocomposite type: duplex AlXN3 (X=Cr) and duplex nACRo3, deposited by LARC and CERC technologies. Duplex coating is a modern technology, which combines plasma nitriding and PVD coating in one cycle. The FIB analysis can be widely used in the field of study of basic materials and technological applications as it is based on highly focused ion beam which enables accurate machining of the investigated specimens and flexible processing at a micro/nanometric level. Cross sections of specimens obtained by FIB-SEMs document the arrangement of individual deposited nanomultilayers within the nanocomposite coatings and their EDS analysis in specific locations.

Fracture Analysis and Mechanical Properties of Magnesium Based Composites

Mechanical properties and microstructure and fracture analysis of a magnesium alloys based composite series with different volume fraction of alumina dispersoid nanoparticles were studied. The initial states of the composites were further treated by severe plastic deformation (SPD) using equal channel angular pressing (ECAP) in order to achieve microstructures with very fine grains of matrix. Microstructure parameters, in particular the matrix grain size, average size of the dispersed particles and their distribution, were observed using optical microscopy. The average grain sizes of MMCs decreased evidently with the increase of the weight percentage of Al2O3 particles additions and ECAP passes. The heat deformation process of such materials, besides the formation of incorporated Al2O3 particles, also leads to the creation of intermetallic compound Mg17Al12. Fracture surfaces after tensile tests at room and elevated temperature were studied by SEM. The fracture of studying materials were characterized as the ductile fracture due to the existence of a large number of dimples.In summary, it has been shown that mechanical properties are affected by lattice, physical parameters of phases within the composite systems. They are also affected by microstructure and substructure, which depend on the technology of compaction and densification.

Testing of PVD Hard Coatings Applied to Coining Dies

The requirements on tools used in the production of coins include high quality and reliability, dependent on the materials from which they are made, on manufacturing technology, heat treatment and final operations achieving functional area modification. Properties of the material of coins vary during their production and there is the so-called operational degradation that can be caused by an inappropriate technology of manufacturing. The quality of coining dies is expressed as their service life which ranges from approximately one hundred thousand to one million pieces of coins produced. Therefore, it is necessary to pay enough attention to the service life of coining dies. Surface treatment in the form of the application of hard PVD coatings is one of the ways of increasing the durability of coining die.In the present study, we analysed and tested three types of coatings deposited onto coining dies made of tool steel.

Evaluation of AlTiCrN Coatings Surface after Tribological Tests

The article deals with the issue of evaluation of thin coatings for coating of cutting tools in order to increase their lifetime at higher temperatures. The aim of the experimental work was to determine the quality of two types of coatings - AlTiNmulti and AlTiCrN. The coatings were applied to the material Böhler 190 Microclean using PLATIT PL1001 Compact device at temperature of 430°C and pressure of 0,020 mbar. To determine the quality of coatings tribological test Pin-on-Disc was used, the counterpart was made of tungsten carbide (WC). Outputs of measurements were evaluated in Sensomp, which evaluates the results obtained from measurements using microscope PLu Noex. The results of the tests show that the AlTiNmulti coating is most suitable for use in environments with higher temperatures.

The Influence of Current Density on Tribological Behavior Ni-Co Electroplated Coatings

Nowadays, more and more scientific studies deal with the formation of electroplating alloy coatings due to the possibility of combination and share content type metal – forming alloy. To produce coatings that fulfil pre-defined specific requirements is possible by a suitable combination of process conditions. The paper deals with the study of tribological properties of Ni-Co coatings that were prepared by electrodeposition technique from sulphate electrolyte on the copper substrate. Effect of current density on the properties of electroplated coatings was determined via a morphology characteristics and micro-hardness of coating′surface. The tribological behaviour of Ni – Co coatings was described by friction coefficient using the pin-on-disc method.