Yazar "Yasar, Abdulkadir" seçeneğine göre listele

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    Effect of trimethylamine borane (TMAB) bath concentration on electrodeposited Ni-B/TiC nanocomposite coatings
    (Elsevier Sci Ltd, 2023) Unal, Ersin; Yasar, Abdulkadir; Karahan, Ismail Hakki
    In this study, stainless steel material was coated with Ni-B alloy-based, TiC particle reinforced composite film using electrochemical deposition method. The properties of the obtained Ni-B/TiC nanocomposite coatings were investigated in terms of the effect of trimethylamine borane (TMAB) bath concentration, which is a boron source. In addition, the data of pure Ni, Ni-B alloy and stainless steel are presented together for comparison. According to the cyclic voltammogram (CV) analysis, it is seen that TMAB contributes to increasing the deposition rate. In the crystal structure analysis, the effect of TMAB was weaker at low TiC bath concentrations, while the effect of TMAB was more dominant at high TiC bath contents. The crystal grain size values of nanocomposite coatings vary between 5.8 and 16.8 nm, and these values decrease up to 86% when compared to the crystal grain size of the pure Ni coating. Although the increase in TMAB initially causes an increase in the microhardness of nanocomposite coatings, when the TMAB value was further increased, it was observed that the microhardness decreased even more compared to the previous initial value. The highest hardness value was obtained in the sample produced at 5 g/l TiC and 6 g/l TMAB bath contents, and this value was 817 HV. Compared to this value, it was observed that the hardness of pure Ni was 65% lower. It was observed that TMAB did not have significant effect on the coating morphology, but the increase in TMAB caused an increase B content and a decrease in the TiC content in the nanocomposite coating. Furthermore, it was revealed that the increase in TMAB bath concentration caused an improvement on corrosion resistance. The corrosion current of the composite sample with 9 g/l TMAB concentration, which showed the best corrosion performance, decreased by 85% compared to pure nickel.
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    Öğe
    Estimation of microhardness and crystal grain size values of electrodeposited Ni-B/TiC nanocomposite coatings by artificial neural networks (ANN) method
    (Elsevier Science Sa, 2023) Unal, Ersin; Yasar, Abdulkadir; Karahan, Ismail Hakki
    In this study, composite coatings with Ni-B alloy main structure reinforced with TiC nanoparticles were coated on a stainless steel substrate by electrodeposition method. The microhardness and crystal structures of the produced nanocomposite films were examined and the relations between the obtained results and the production parameters were discussed in detail. In addition, the surface and section morphologies of the coatings were analyzed by SEM and EDS. Furthermore the complex relationship between the experimentally obtained microhardness, crystal grain size values and the production parameters was modeled by artificial neural networks (ANN) method. According to the hardness results, nanocomposite coatings microhardness values varied between about 470 HV and 820 HV. In XRD examinations, the crystal grain size values of nanocomposite coatings were found ranging from 6.6 nm to 17.4 nm. From the morphology results, it is understood that the surface structure and coating thicknesses are remarkably affected by the production parameters. Considering the EDS results, it was observed that the alloying with boron and the TiC reinforcement were successfully applied in nanocomposite coatings. With respect to the results obtained with ANN, the best results were obtained in the model with 10 neurons in the hidden layer and the highest error value of 2.02% was achieved for microhardness values. For the crystal grain size, the most successful results were acquired in the model with 12 neurons and the highest error value was obtained as 3.397%.
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    Investigation of the Properties of Ni-B/TiC Nanocomposite Coatings Produced at Different Particle Concentrations by Electrodeposition
    (Springer, 2023) Unal, Ersin; Yasar, Abdulkadir; Karahan, Ismail Hakki
    In this experimental work, Ni-B/TiC nanocomposite coatings were deposited on a stainless steel substrate by conventional electrodeposition method and their features such as hardness, crystalline structure, corrosion and wear behavior were investigated. Furthermore, the same method was carried out in order to produce pure Ni and Ni-B alloy coatings and their properties were analyzed for comparison purposes. It was observed that nanocomposite coatings had much lower crystal grain size than pure Ni and slightly higher crystal grain size than Ni-B alloy. As a result of SEM analysis, it was determined that both B element and TiC particles were homogeneously deposited into the main structure, and the surface morphology was also affected by these components. According to the microhardness results, it was noted that the nanocomposite coating hardness with the highest hardness value increased by 160 pct compared to the pure Ni and 90 pct more than the Ni-B alloy. In the corrosion analysis, the corrosion resistance of nanocomposite coatings with TiC reinforcement improved significantly, and it was determined that the sample with 12 g/l TiC bath concentration performed 371 pct better than pure Ni and 440 pct better than Ni-B alloy in terms of corrosion current. Moreover, it was determined that the wear performance of nanocomposite coatings improved with increasing hardness and there was a 90 pct reduction in wear volume loss when compared to pure Ni.
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    A review of electrodeposited composite coatings with Ni-B alloy matrix
    (Iop Publishing Ltd, 2019) Unal, Ersin; Yasar, Abdulkadir; Karahan, Ismail Hakki
    Coating processes are of great importance for protecting the materials used in the industry from the damaging effects of external environments and mechanical forces. There are a wide variety of coating methods, but the electrochemical deposition method within them is one step ahead because of its low cost, easy manufacturability and rapidity. Ni-B coatings have been produced for many years by the electroless deposition method, but electrodeposited Ni-B coatings are a relatively new research topic and attract much attention in recent years. Due to its superior properties Ni-B alloy coatings are successfully used in many industries such as aerospace, automotive, petrochemical, chemical and electronics. Works on reinforcing Ni-B alloys with second phase particles to increase these properties to a better level has been increasing rapidly in recent years. Ni-B alloy and composite coatings were investigated in this study. Furthermore, the bath components, production parameters, contents and properties of Ni-B alloy matrix composite coatings were presented comparatively. It was revealed that reinforcing the Ni-B alloy matrix with ceramic particles affected properties such as crystal structure, morphology, hardness, corrosion and abrasion resistance very seriously.