%0 Journal Article %J The International Journal of Advanced Manufacturing Technology %D 2023 %T Analysis of the machinability of different types of sintered carbides with WEDM in both water and oil baths %A Mouralova, Katerina %A Benes, Libor %A Prokes, Tomas %A Zahradnicek, Radim %A Fries, Jiri %A Plichta, Tomáš %K AIF %K MF %X

The unconventional wire electric discharge machining (WEDM) technology represents a vital manufacturing technology in different industrial branches. This technology is essential because of the possibility to machine difficult-to-machine materials such as sintered carbides. For this reason, this study analyses the machinability of sintered carbides WKP23S, WSM33S and WK1 with WEDM in both water and oil baths. We investigated the influence of the machining parameters, namely, pulse off time, gap voltage, discharge current, pulse on time and wire feed, on the cutting speed, surface roughness and defect occurrence. We investigated 9 different roughness parameters, analysed surface morphology with an electron microscope and also analysed cross-sectioned samples. We found out that machining sintered carbides in oil bath yields better results than machining in deionized water. The oil tank prevents the removal of the cobalt binder, but it does not reduce fissure occurrence in any significant way. The lowest Ra value, that is 0.7 µm, was recorded for the WKP23S sample when machined in oil and Ra 0.9 µm when the same material was machined in water.

%B The International Journal of Advanced Manufacturing Technology %G eng %U https://doi.org/10.1007/s00170-023-10913-4 %R 10.1007/s00170-023-10913-4 %0 Journal Article %J Scientific Reports %D 2022 %T Production of precision slots in copper foil using micro EDM %A Mouralova, Katerina %A Bednar, Josef %A Benes, Libor %A Plichta, Tomáš %A Prokes, Tomas %A Fries, Jiri %K AIF %K MF %B Scientific Reports %V 12 %P 5023 %8 MAR 23 %G eng %R 10.1038/s41598-022-08957-9 %0 Journal Article %J Polymers %D 2021 %T The Adhesion of Plasma Nanocoatings Controls the Shear Properties of GF/Polyester Composite %A Plichta, Tomáš %A Širjovová, Veronika %A Zvonek, Milan %A Kalinka, Gerhard %A Čech, Vladimír %K AIF %K MF %X

High-performance fibre-reinforced polymer composites are important construction materials based not only on the specific properties of the reinforcing fibres and the flexible polymer matrix but also on the compatible properties of the composite interphase. First, oxygen-free (a-CSi:H) and oxygen-binding (a-CSiO:H) plasma nanocoatings of different mechanical and tribological properties were deposited on planar silicon dioxide substrates that closely mimic E-glass. The nanoscratch test was used to characterize the nanocoating adhesion expressed in terms of critical normal load and work of adhesion. Next, the same nanocoatings were deposited on E-glass fibres, which were used as reinforcements in the polyester composite to affect its interphase properties. The shear properties of the polymer composite were characterized by macro- and micromechanical tests, namely a short beam shear test to determine the short-beam strength and a single fibre push-out test to determine the interfacial shear strength. The results of the polymer composites showed a strong correlation between the short-beam strength and the interfacial shear strength, proving that both tests are sensitive to changes in fibre-matrix adhesion due to different surface modifications of glass fibres (GF). Finally, a strong correlation between the shear properties of the GF/polyester composite and the adhesion of the plasma nanocoating expressed through the work of adhesion was demonstrated. Thus, increasing the work of adhesion of plasma nanocoatings from 0.8 to 1.5 mJ·m−2 increased the short-beam strength from 23.1 to 45.2 MPa. The results confirmed that the work of adhesion is a more suitable parameter in characterising the level of nanocoating adhesion in comparison with the critical normal load.

%B Polymers %V 13 %P 593 %G eng %U https://www.mdpi.com/2073-4360/13/4/593 %R 10.3390/polym13040593