The need for non-conventional natural fibres for synthesis of hybrid composites has gained momentum in the recent past. Taking into consideration this need, in the current study, hybrid composites were fabricated by reinforcing wood apple shell powder and coconut shell powder, in the resin with varying amounts of cenospheres (up to 20 wt% in increments of 5 wt%) to evaluate their mechanical and tribological properties. The densities of these composites were directly correlated with the quantity of additives utilized. Enhanced tensile and flexural properties were noted in composites containing 10 wt% cenospheres, along with 15 wt% wood apple shell powder and coconut shell powder, compared to other formulations. Dry sliding wear tests were performed at room temperature using a pin-on-disc apparatus, considering loading factors, travel distance, and speed. A hybrid composite consisting of 10 wt% cenospheres, subjected to a normal load of 10 N (1.02 kgf), and tested at a sliding speed of 1.5 m s⁻¹ (90 m min⁻¹) over a distance of 500 m, exhibited superior wear resistance compared to all other composite variations.

Presently, the world is looking for non-polluting, non-toxic, renewable, low density, corrosion resistant, eco-friendly, and low-cost material as replacement for the most challenging elements like plastics and its derivatives. Meanwhile, some of the composites were also made with some challenging facts concerning biodegradability properties. Thereby this is an attempt to make use of natural sources in the composite preparation and reduce the extra burden caused by unwanted materials on the earth. In this study, economical filler materials such as untreated and alkali treated Areca Leaf Sheaths (ALS) are studied for physical and mechanical characterization. Among these, alkali treated-oven dried ALS samples have shown improved results in terms of density, thickness and mechanical properties as compared to untreated-sun dried samples. From XRD, FTIR, and SEM analysis, it was concluded that, the surface modification will enhance the micro-fibrillation of the areca leaf sheath fibers and this will increase the mechanical properties.

Metal matrix composites have captured considerable interest in tribological applications, largely owing to their remarkable characteristics, which include a high strength-to-weight ratio and a low wear rate. This investigation delves into the exploration of hybrid metal matrix composites, where cobalt and chromium play the role of reinforcing agents within a bronze foundation. These composites were manufactured through a powder metallurgy process, utilizing cobalt and chromium metal powders with a particle size of 40 μm. Various weight percentage ratios (2.5%, 5.0%, and 7.5%) were utilized to create these composite specimens. To assess their tribological performance, the composite samples were subjected to a sliding wear test using a pin on disk machine, following the ASTM G99 standards. The wear characteristics of these composites were analyzed using the Taguchi method, considering parameters such as the applied load, speed, reinforcement percentage, and sliding distance. In addition, we conducted an analysis of variance on the collected data. To analyze the wear behavior of these hybrid metal matrix composites based on bronze, we utilized both multiple linear regression analysis and a signal-to-noise ratio assessment. The results indicate that the inclusion of cobalt and chromium metal powders as reinforcement materials enhances the tribological properties of the bronze matrix material.