In order to reveal the effect of carbon content on tribological performance of coatings, TiAlC films having four different amounts of carbon content were synthesized using DC pulse magnetron sputtering. The amount of carbon was varied by using different graphite target powers of 400, 450, 500 and 550W while keeping the TiAl target power fixed at 80W. Sliding friction and wear behavior of TiAlC nanostructured films deposited on Si (100) substrates by (DC) pulse magnetron sputtering was examined against steel ball using a ball on disk configuration' at a load of 1 N and sliding speed of 7 mm/s. The film deposited at 500W graphite target power attained a hardness of ~20.24 GPa and elastic modulus of 246 GPa. Tribological test results indicate that the film fabricated at (500W, 25 at. %C) has the lowest coefficient of friction (COF) of 0.29 and wear rate of 6.52×10⁻¹³ (mm³/Nm). The observed behavior has been attributed to presence of higher nano crystalline graphite phase, compact coating, uniform microstructure and formation of carbon rich oxide layer. Scrutiny of the nano indentation statistics showed that resistance to plastic deformation (H³/E^*2) and elastic strain to failure (H/E^*) increase with increasing target power and reaches the highest value at (500W, 25 at. %C) in TiAlC films.

Copper (Cu) metal matrix composites have gained significant attention due to their potential for usage in numerous applications, including aerospace, automotive

It is well known that nitrite is widely used in industrial and agricultural sectors as a preservative, corrosion inhibitor, and intermediate in chemical synthesis; consequently, nitrite residues are often present in food, water, and the environment as a result of meat curing, fertilizer use, and wastewater discharge. Despite having several applications, nitrite exerts toxic effects on human beings and aquatic life. Therefore, the monitoring of nitrite is of particular significance to avoid negative impacts on human health, the environment, and aquatic life. Previously, the electrochemical method has been extensively used for the development of nitrite sensors using various advanced electrode materials. Additionally, zinc oxide (ZnO), cerium oxide (CeO₂), titanium dioxide (TiO₂), copper oxide (CuO), iron oxides, nickel oxide (NiO), polymers, MXenes, reduced graphene oxide (rGO), carbon nanotubes (CNTs), graphitic carbon nitride (gCN), metal–organic frameworks (MOFs), and other composites have been utilized as electrocatalysts for the fabrication of nitrite electrochemical sensors. This review article provides an overview of the construction of nitrite sensors using advanced electrode materials. The electrochemical activities of the reported nitrite sensors are discussed. Furthermore, limitations and future perspectives regarding the determination of nitrite are discussed.

In the era of modern technology, tribo coupling components require efficient lubrication to ensure optimal performance, and to avoid significant material loss throughout the entire duty cycle. Solid lubricants, when reinforced with optimal contents, have shown the ability to improve the tribological performance and sustain the lubricious behavior over extended periods. The goal of this study is to improve the reliability and lifetime of tribo components used in a variety of industrial applications. The investigation explores the lubrication mechanisms, and optimizes the tribological behavior of the Ni-based alloy coating impregnated with molybdenum disulfide (MoS₂) and varying contents of silver (Ag). Specifically, four compositions containing 7 wt.% MoS₂ with different contents of Ag, i.e., 5, 10, 15, and 20 wt.%, were developed via the HVOF route and tested from room temperature (RT) to 800 °C. The optimal composition was determined using a parametric experimental optimization approach based on friction and wear minimization. In particular, the coating with 15 wt.% Ag showed the least friction and wear across all tested temperatures. The coating material having 15 wt.% Ag along with 7 wt.% MoS₂ attained a COF of 0.22 and wear rate of 5.3 × 10⁻⁶ mm³/Nm at 800 °C. The optimal content of Ag (15 wt.%) in the coating (NC15) decreased the wear rate by approximately 27% compared to the 20 wt.% Ag variant (NC20) at 800 °C. Overall friction and wear of the derived coatings decreased at 800 °C, with a minor increase at 400 °C. The apparent behavior demonstrated the complex interplay between coating ingredients and testing temperatures. The favorable tribo-chemical reactions and efficient boundary lubrication mechanisms worked together to reduce friction and wear.

Keeping in view the importance of the Cu based composites in sliding electric contact applications, the aim of the study is synthesise copper-chromium alloy based composites containing different wt. % of TiC by using a cost effective stir casting technique and to compare their mechanical and tribological behaviour. The study also proposes to analyse the friction and wear behaviour of the formed composites under the sliding speed of 1m/s and load varied 5 N, 10 N, 15 N and 20 N. The hardness of the composite Cu-1wt%Cr-1wt%TiC and Cu-1wt%Cr-2wt%TiC has been found to increase slightly when compared with Cu-Cr alloy and as received Cu. The wear rate was found to show linear trend with increasing normal load following the Archard law. However, composites were found to show low wear as compared to that observed in pure copper. This might be due to high hardness of the composite, the compact transfer layer of wear debris and due to presence of hard TiC particles whicg results in a lower real area of contact which further causes lower wear. There was found no cracks in the composite. The addition of chromium was found to increase the wettability and mechanical properties. The composite hardness and strength was found to increase with addition of TiC and chromium element in the matrix phase up to certain content.