Surface roughness reflects the quality of many operational parameters, namely service life, wear characteristics, working performance and tribological behavior of the produced part. Therefore, tribological performance is critical for the components used as tandem parts, especially for the MMCs (Metal Matrix Composites) which are a unique class of materials having extensive application areas such as aerospace, aeronautics, marine engineering and the defense industry. Current work covers the optimization study of production parameters for surface roughness and tribological indicators of newly produced cast iron reinforced bronze MMCs. In this context, two levels of temperature (400 and 450 °C), three levels of pressure (480, 640 and 820 MPa) and seven levels of reinforcement ratios (60/40, 70/30, 80/20, 90/10, 100/0 of GGG40/CuSn10, pure bronze-as received and pure cast iron-as received) are considered. According to the findings obtained by Taguchi’s signal-to-noise ratios, the reinforcement ratio has a dominant effect on surface roughness parameters (Ra and Rz), the coefficient of friction and the weight loss in different levels. In addition, 100/0 reinforced GGG40/CuSn10 gives minimum surface roughness, pure cast iron provides the best weight loss and pure bronze offers the desired coefficient of friction. The results showed the importance of material ingredients on mechanical properties by comparing a wide range of samples from starting the production phase, which provides a perspective for manufacturers to meet the market supply as per human requirements.

Tribological properties are important to evaluate the in-service conditions of machine elements, especially those which work as tandem parts. Considering their wide range of application areas, metal matrix composites (MMCs) serve as one of the most significant materials equipped with desired mechanical properties such as strength, density, and lightness according to the place of use. Therefore, it is crucial to determine the wear performance of these materials to obtain a longer life and to overcome the possible structural problems which emerge during the production process. In this paper, extensive discussion and evaluation of the tribological performance of newly produced spheroidal graphite cast iron-reinforced (GGG-40) tin bronze (CuSn10) MMCs, including optimization, statistical, graphical, and microstructural analysis for contact zone temperature and specific wear rate, are presented. For this purpose, two levels of production temperature (400 and 450 °C), three levels of pressure (480, 640, and 820 MPa), and seven different samples reinforced by several ingredients (from 0 to 40 wt% GGG-40, pure CuSn10, and GGG-40) were investigated. According to the obtained statistical results, the reinforcement ratio is remarkably more effective on contact zone temperature and specific wear rate than temperature and pressure. A pure CuSn10 sample is the most suitable option for contact zone temperature, while pure GGG-40 seems the most suitable material for specific wear rates according to the optimization results. These results reveal the importance of reinforcement for better mechanical properties and tribological performance in measuring the capability of MMCs.

Fiber-reinforced polymer matrix composites (FRCs) offer advantages such as high strength-to-weight ratio, low density, and cost-effectiveness. However, their limited electrical and thermal conductivity poses challenges in applications such as lightning protection, electromagnetic shielding, and radar absorption. In this study, the effect of PEDOT:PSS content as a coating on layered composites to enhance electrical conductivity and adhesion properties is systematically investigated for the first time. This study explores alternative methods to enhance conductivity, focusing on the adhesion stability of the conductive coating PEDOT:PSS on aramid, carbon, and glass FRCs. Three surface treatment methods—plasma treatment (PT), piranha solution treatment (PI), and a combination of GLYMO/APTES (GA)—were tested for their effects on surface energy and adhesion strength. FTIR spectroscopy revealed significant changes in surface bonds, indicating improved adhesion through new chemical interactions. Contact angle measurements showed improved wettability, with plasma and GA treatments yielding the best results. Peeling tests demonstrated minimal changes in electrical resistance after repeated cycles for plasma- and GA-treated surfaces, highlighting their durability. Cross-cut adhesion tests confirmed that plasma-treated surfaces exhibited the strongest adhesion. This study contributes to the understanding of surface coating techniques to enhance the electrical performance and durability of FRCs, with implications for aerospace, defense, energy, and other industries.

Epoxy thermosets offer excellent dimensional stability and mechanical rigidity, but their inherent brittleness limits their durability in dynamic sliding applications. To overcome this limitation, we synthesized a multi-dimensional hybrid filler composed of one-dimensional Tellurium Nanowires (Te NWs) and Titanium Diboride (TiB₂) particles via an in situ hydrothermal method to improve the dry-sliding friction and wear resistance of the epoxy matrix. Neat epoxy and nanocomposites containing 0.25–1.00 wt.% hybrid filler were tested against hardened AISI 8620 steel over a sliding distance of 2000 m at normal loads of 5–10 N and sliding velocities of 1.00–1.75 m/s. Tribological stability and wear behavior were systematically assessed using the mean coefficient of friction (COF), dispersion metrics (standard deviation, coefficient of variation, and interquartile range), percentage mass loss, infrared thermography, and field-emission scanning electron microscopy (FESEM) of the worn surfaces. The hybrid composites showed a nonlinear tribological response to filler loading. The 0.50 wt.% Te NW–TiB₂/epoxy composite delivered the best overall performance, particularly under the most demanding conditions (10 N and 1.75 m/s). It achieved the lowest mean COF (0.181 ± 0.027), minimal percentage mass loss (0.12%), a narrow friction distribution (coefficient of variation ≤ 13.61%; interquartile range ≤ 0.027), and a lower maximum surface temperature measured by infrared thermography (54.1 °C, compared with 68.6 °C for neat epoxy). Criterion weights were calculated using the Criteria Importance Through Intercriteria Correlation (CRITIC) method and validated using the entropy method. Across all four multi-criteria decision-making methods, the 0.50 wt.% formulation consistently ranked highest, identifying it as the best-performing hybrid composition within the tested range, with 0.75 wt.% as a close alternative.