Wpływ niobu i tytanu w materiale rodzimym i spoiwie na korozję międzykrystaliczną stali nierdzewnych

The article describes the effect of alloyed additives in base material and filler metal on intergranular corrosion. Steel 1.2 mm thick, titanium-stabilized ferritic stainless steel and titanium and niobium-stabilized ferritic stainless steel have been surfacing method MAG (135). The specimens received was subjected to macro and microscopic tests, hardness tests and the intergranular corrosion resistance test. The study showed a higher corrosion resistance of niobium and titanium stabilized steel from titanium-stabilized steel. In addition, a ferritic fine-grain structure was found in the padding axis made with the use of filler metal with titanium and niobium microadditives.W artykule opisano wpływ dodatków stopowych w materiale rodzimym i spoiwie na korozje międzykrystaliczną. Blachy o grubości 1,2 mm ze stali nierdzewnej ferrytycznej stabilizowanej tytanem oraz stali nierdzewnej ferrytycznej stabilizowanej tytanem i niobem zostały napawane metodą MAG (135). Otrzymane próbki poddano badaniom makro i mikroskopowym, zmierzono twardość oraz przeprowadzono badania odporności na korozje międzykrystaliczną. W wyniku przeprowadzonych badań stwierdzono wyższą odporność korozyjną stali stabilizowanej niobem i tytanem od stali stabilizowanej tylko tytanem. Ponadto, wykazano występowanie struktury drobnoziarnistej ferrytycznej w osi napoiny wykonanej przy użyciu materiału dodatkowego z mikrododatkami tytanu i niobu

Badanie struktury i własności tribologicznych napawanej plazmowo proszkowo warstwy trudnościeralnej

The following study presents the results of wear-resistant layer made of Ni-Cr-Si-B-Fe-C+WC alloy in the form of metallic powder on the AISI 4715 steel. Hardness and abrasion resistance tests were performed in accordance to PN-EN ISO 6508-1:2016 and ASTM G65-00 standards. Obtained data were compared to the abrasion resistant steel produced by Swedish manufacturer. Microscopic observations were made to determine the structure of obtained layer and base material using Olympus SZX9 stereoscopic light microscope. In order to determine the chemical composition of microregions, X-ray microanalysis researches were carried out.W artykule przedstawiono wyniki badań dotyczące napawanej ręcznie plazmowo warstwy trudnościeralnej wykonanej stopem Ni-Cr-Si-B-Fe-C+WC w postaci proszku metalicznego na podłożu stali AISI 4715. Przeprowadzono pomiary twardości warstwy zgodnie z PN-EN ISO 6508-1:2016 oraz odporności na zużycie ścierne wg ASTM G65-00 porównując uzyskane dane z wynikami uzyskanymi dla trudnościeralnej blachy szwedzkiego producenta. Wykonano obserwacje metalograficzne mikroskopowe badanej warstwy oraz materiału podłoża przy wykorzystaniu stereoskopowego mikroskopu świetlnego Olympus SZX9. W celu określenia jakościowego i ilościowego składu chemicznego mikroobszarów napoiny przeprowadzono badania metodą mikroanalizy rentgenowskiej

Effect of contaminations and surface preparation on the work function of single layer MoS2

Thinning out MoS2 crystals to atomically thin layers results in the transition from an indirect to a direct bandgap material. This makes single layer MoS2 an exciting new material for electronic devices. In MoS2 devices it has been observed that the choice of materials, in particular for contact and gate, is crucial for their performance. This makes it very important to study the interaction between ultrathin MoS2 layers and materials employed in electronic devices in order to optimize their performance. In this work we used NC-AFM in combination with quantitative KPFM to study the influence of the substrate material and the processing on single layer MoS2 during device fabrication. We find a strong influence of contaminations caused by the processing on the surface potential of MoS2. It is shown that the charge transfer from the substrate is able to change the work function of MoS2 by about 40 meV. Our findings suggest two things. First, the necessity to properly clean devices after processing as contaminations have a great impact on the surface potential. Second, that by choosing appropriate materials the work function can be modified to reduce contact resistance

14-GHz GaNAsSb unitraveling-carrier 1.3-μm photodetectors grown by RF plasma-assisted nitrogen molecular beam epitaxy

We report on picosecond pulsed response and 3-dB cutoff frequency of 1.3-μm GaNAsSb unitraveling-carrier photodetectors (PDs) grown by molecular beam epitaxy using a radiofrequency plasma-assisted nitrogen source. The 0.1-μm-thick GaNAsSb photoabsorption layer contains 3.5% of N and 9% of Sb, resulting in a bandgap of 0.88 eV. The dark current densities at 0 and .9 V are 6 and 34 mA/cm2, respectively. The GaNAsSb UTC PDs exhibit a temporal response width of 46 ps and a record 3-dB cutoff frequency of 14 GHz at -9 V

High-Speed GaN/GaInN Nanowire Array Light-Emitting Diode on Silicon(111)

The high speed on–off performance of GaN-based light-emitting diodes (LEDs) grown in c-plane direction is limited by long carrier lifetimes caused by spontaneous and piezoelectric polarization. This work demonstrates that this limitation can be overcome by m-planar core–shell InGaN/GaN nanowire LEDs grown on Si(111). Time-resolved electroluminescence studies exhibit 90–10% rise- and fall-times of about 220 ps under GHz electrical excitation. The data underline the potential of these devices for optical data communication in polymer fibers and free space