Articles written in Bulletin of Materials Science

    • Ni–Fe–Al$_2$O$_3$ electrodeposited nanocomposite coating with functionally graded microstructure


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      In this study, a Ni–Fe–Al$_2$O$_3$ nanocomposite coating was deposited on the substrate of low-carbon steel by electrodeposition from a sulphate-based bath. The effects of frequency and duty cycle were investigated to producethe functionally graded (FG) coating. For this purpose, first, the coatings with duty cycle-decreased method (DDM) were deposited in eight steps from 88 to 11%. At the second step, frequency-increased method (FIM) was utilized from 50 to 6400 Hz during eight steps. Assessing of coatings was carried out by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), potentiodynamic test, Vickers microhardness test and wear test.Microstructure evaluations gained by SEM and EDS demonstrated that the continuous alterations of duty cycle contribute for manufacturing of FG coatings, so that the maximum particle fraction was in the free surface of the coating and its amount was gradually decreased to the interface. These investigations showed that FIM had no effect on production of graded structure. Corrosion and wear tests indicated high corrosion and wear resistance of DDM coatings in comparison to FIM coatings. Investigating the best coatings obtained from both above methods exhibited 50 and 20% reduction in corrosion current density and wear rate, respectively, for DDM specimen in comparison to FIM sample.

    • Corrosion and wear behaviour of multilayer pulse electrodeposited Ni–Al$_2$O$_3$ nanocomposite coatings assisted with ultrasound


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      In this study, the Ni/Al$_2$O$_3$ nanocomposite multilayer coatings with six consecutive layers were electrodeposited on the mild steel by pulse electrodeposition with ultrasound agitation from nickelWatts-type bath. Thestructure and morphology of the etched coatings cross-section were characterized by scanning electron microscopy (SEM). The corrosion behaviour of these coatings was investigated in 1 M H$_2$SO$_4$ solution. All of the coatings showed the active–passive transition and the distinct difference in structure had negative influence on their corrosion resistance. Moreover, the tribological behaviour of these coatings was evaluated by pin-on-disc type. The results showed that wear resistance increased with increase in duty cycle and frequency.

    • Study on wear and corrosion properties of functionally graded nickel–cobalt–(Al$_2$O$_3$) coatings produced by pulse electrodeposition


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      Functionally graded nickel–cobalt coatings with/without alumina nanoparticles were pulse electrodeposited on a carbon steel substrate by a continuous decrease in duty cycle from 95 to 10% at different frequencies of 100, 500and 1000 Hz. The effect of pulse parameters on the nanoparticle content, chemical composition, microstructure, corrosion properties and tribological behaviour of coatings was studied. Energy-dispersive X-ray spectroscopy analysis showed that the amount of cobalt is gradually reduced and the content of alumina nanoparticles is increased from the substrate/coating interface to the surface. Based on the electrochemical studies in 3.5 wt% NaCl, the nanocomposite coatings gain the highest corrosion resistance at the lowest frequency. Also, the hardness of coatings gradually increased. Evaluation of the tribological behaviour of coatings by a pin-on-disk wear test showed that the nanoparticles have a positive effect on wear resistance and improve it by increasing frequency.

  • Bulletin of Materials Science | News

    • Dr Shanti Swarup Bhatnagar for Science and Technology

      Posted on October 12, 2020

      Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
      Chemical Sciences 2020

      Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
      Physical Sciences 2020

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

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