Friction and wear are very crucial aspects of the performance, service life, and the operational costs for a mechanical component or equipment. To reduce the friction and wear at the interface of the sliding or mating parts, different conventional binary coatings like TiN, CrN, TiC, etc., have been used in the last two decades. But ternary nitride coatings have replaced the binary coatings due to better tribo-mechanical properties. Now, ternary nitride coatings are being extensively used in several fields such as cutting tools, machinery parts, orthopedic implants, microelectronics, marine equipment, decorative purposes, automotive, aerospace industry, etc. Many researchers have developed and investigated the ternary nitride coatings for different applications. Nonetheless, there is a huge research potential in the development and optimization of the tribo-mechanical properties of the ternary nitride coatings. Therefore, tribo-mechanical studies of the ternary nitride coatings are needed for fostering the new industrial applications. This paper is focused to summarize and compare the tribo-mechanical properties of the ternary nitride coatings comprehensively and aims to explore the novel research directions in the development of the ternary nitride coatings.

The surface coating is one of the novel approaches to enhance the performance and durability of the mechanical components by decreasing the wear and friction among two interacting bodies. In this study, tribological and mechanical properties of titanium nitride (TiN) coatings were investigated on the AISI 52100 bearing steel deposited by low-temperature physical vapor deposition system. Surface morphology and elemental composition of the TiN coating were analyzed by scanning electron microscope and energy-dispersive X-ray spectrum, respectively. Substrate surface roughness and coating thickness of TiN were varied for correlative analysis among adhesion, mechanical, and tribological properties. Scratch and tribo tests were performed for evaluating the adhesion and tribological properties, respectively. Samples having the substrate surface roughness (0.2 ± 0.05 µm) and the coating thickness of more than 2.83 µm presented relatively better adhesion, wear resistance, and lower coefficient of friction of the TiN coating.

Fuel spray characteristics influence combustion, which in turn has a direct impact on engine performance and emissions. Recently, there has been an increasing interest in novel castor oil biodiesel. However, few investigations have been performed that combine both numerical and experimental biodiesel spray analyses. Hence, in this paper, we aim to explore the spray behavior of castor and jatropha biodiesel by employing numerical and experimental methods under non-evaporating, varying injection, and ambient conditions. The experimental study was carried out in a control volume vessel (CVV) at high injection and ambient pressures. The fuel atomization was modelled in ANSYS Fluent using a Lagrangian/Eulerian multiphase formulation. The results revealed that the Kelvin–Helmholtz and Rayleigh–Taylor (KHRT) model coupled with the Taylor Analogy Breakup (TAB) model provide a better estimation of the penetration length (PL) and spray cone angle (SCA) compared to the KH and TAB models. On average, Jatropha biodiesel (JB-20) and castor biodiesel (CB-20) showed a 10% to 22% longer PL, 8% to 10.6% narrower spray cone angles, and 3% to 6% less spray area, respectively, compared to diesel. The numerical predictions showed that JB-20 and CB-20 had an around 24.7–48.3% larger Sauter mean diameter (SMD) and a 38.6–73.3% average mean diameter (AMD).