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- MakaleAçık Erişim2025Scopus SJRQ2Effect of B4C Amount on Microstructural and Mechanical Properties of Cu/h-BN/B4C Metal Matrix Composites Fabricated via Spark Plasma Sintering
Çelebi, Müslim; Karabacak, Abdullah Hasan; Özkaya, Serdar; Çelik, Ertuğrul; Sekban, Dursun Murat; Çanakçı, Aykut; Yanar, Harun
Copper (Cu) is widely used in electrical, electronic, and tribological systems owing to its excellent electrical and thermal conductivity. However, its relatively low hardness and poor wear resistance limit its use in demanding engineering applications. In this study, Cu-based hybrid metal matrix composites (MMCs) reinforced with hexagonal boron nitride (h-BN) and boron carbide (B4C) were fabricated via spark plasma sintering (SPS) to improve their mechanical and tribological performance. The h-BN content was fixed at 1 wt.% to ensure solid lubrication, while the B4C content was varied (0.25, 0.5, 0.75, and 1 wt.%) to examine its influence on the microstructural, mechanical, electrical, and wear properties of the composites. Microstructural analyses confirmed a homogeneous distribution of h-BN and B4C particles in the Cu matrix at low and moderate reinforcement levels, whereas excessive B4C resulted in partial agglomeration and reduced densification. All composites achieved relative densities above 95%, demonstrating the high densification efficiency of the SPS process. Hardness increased markedly with B4C addition due to dispersion strengthening and grain refinement, while electrical conductivity decreased slightly because of the insulating nature of the reinforcements. Tribological tests showed that the composite containing 0.75 wt.% B4C exhibited the best performance, with the lowest wear rate and stable friction behavior. Overall, the results indicate that co-reinforcing Cu with h-BN and B4C through SPS is a promising strategy for developing multifunctional materials suitable for electrical contact and sliding applications.
AtıfScopus11WoS12OpenAlex12
İncele - MakaleAçık Erişim2024Scopus SJRQ2Genotoxic effects of copper nanoparticles on Vicia pannonica Crantz. root meristem cells
Tasar, Neslihan
With the increasing use of metal nanoparticles, their access to the food chain has become the main concern for scientists. The present study sheds light on the copper nanoparticles (Cu NPs), which are widely used in many industries today. For this purpose, Vicia pannonica Crantz., a common fodder plant, was used and exposed to metal-based Cu NPs. To determine the genotoxic effects on root meristem cells, total of 3 different concentrations (50 ppm, 150 ppm, and 300 ppm) of Cu NPs and the control in deionized water solutions were prepared. The determination of the accumulation and elimination of Cu NPs in Vicia pannonica used in the study was carried out using with X-ray diffraction (XRD), scanning electron microscopy (SEM), SEM element mapping, and energy dispersive X-ray diffraction (EDS) characteristic spectrum analysis. All doses of Cu NPs caused significant decreases in the Mitotic index of V. pannonica meristem cells compared to the control. Multiple analyzes carried out in the study showed that Cu NPs caused abnormalities in cell division such as C-metaphase, polar aberration, deconstructed anaphase, chromosome breakage, loss of genetic material, failure to assemble in the metaphase plate, deconstructed metaphase, asynchronous division remaining chromosome in metaphase, adhesion, deconstructed prophase, advanced chromosomes, and chromosome bridges in anaphase. Results support that Cu NPs have a genotoxic effect on V. pannonica.
AtıfScopus5WoS2OpenAlex6İncele