In this series of posts, we are trying to review scientific research related to our company’s activities.
The title of the article we will review today is:”Electrochemical characteristics of nano-structure TiCN coatings on the tool steel deposited by PACVD in various solutions.”
Authors and Journal: The paper was written by Zeynab Dadashi Shanbaraki, Mahboobeh Azadi, and Amirhossein Hafazeh. It was published in the journal Results in Chemistry.
This study investigates the electrochemical behavior of various nano-structure TiCN coatings prepared using a plasma-assisted chemical vapor deposition (PACVD) technique in acidic and alkaline solutions. The N2/Ar ratio was varied to explore its effect on the microstructure and electrochemical properties of coatings on the steel cold-work tool. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) measurements were carried out in various corrosive solutions. Field emission scanning electron microscopy and X-ray diffraction were also utilized to evaluate the microstructure and phase detection. The EIS results showed that the resistance of TiCN coatings increased by about 94.3% based on the equiaxed structure and small size of the coating cluster in 3.5% wt NaCl solution after 24 hours. The lowest corrosion rate with a value of 5.9 µA cm² at 37°C after 24 hours was attributed to the TiCN coating with the N2/Ar ratio of 0.4 according to exhibiting the highest Ti content and changes in present phases. The N2/Ar ratio of 0.7 effectively increased the impedance resistance to 97.5% based on PP test results in 3 M H2SO4 solution. This behavior was related to the lowest value of the C/N ratio and the highest coating thickness.
The paper also discusses the challenges of incorporating reactive elements (RE) into turbine coatings, which can lead to compromised strength, heightened brittleness, and reduced adhesion. However, RE oxides offer advantages of avoiding these detrimental effects, counteracting corrosion phenomena induced by V2O5 compounds, and enhancing oxidation resistance. The study emphasizes the importance of optimizing RE oxide particle incorporation and understanding the influence of particles in coating microstructures.
Key Features of Research:
- Development of Ni–Al and Ni-Cr-Al type MMC coatings with Y2O3 nanoparticles.
- Enhanced oxidation and corrosion resistance due to Y2O3 nanoparticles.
- Reduction of interdiffusion and improved oxide scale adherence.
- Potential application for advanced turbine blade coatings.
- Challenges and solutions for incorporating reactive elements into turbine coatings.