The study was conducted to use fish scales powder as animal biomass to prepare epoxy composites. Fish scales powder is beneficial in reducing environmental pollutants. The fish scales powder was added to the epoxy matrix for improving the interfacial bonding between the scales and the epoxy matrix. However, a direct method was used to prepare epoxy composites, and samples were cut according to ASTM standards for mechanical and tribological tests. Interfacial interaction between the fish scales powder and epoxy was investigated by FTIR and SEM. It was found that the fish scales powder contents affect the mechanical properties and tribological behaviour of produced composites. Compared to pure epoxy, the load of 10 wt.% fish scales powder increased the tensile strength by 16.0%. As well as, the coefficient of friction was reduced by 16.0% and wear resistance was enhanced by 48.58%. The improvements in the performance of composites are contributed to the hydrogen bonding formed between fish scales powder and epoxy matrix.

In order to meet the requirements of lightweight, high strength, and wear resistance, metal matrix composites are being manufactured with increasing interest, according to recent advancements in material science. Alumina (Al2O3) and Graphite (Gr) were added to the aluminum alloy matrix (AA6061) to increase the dry sliding wear resistance and to explore the impact of normal applied load and sliding speed on the coefficient of friction as well as its wear behavior. The composites were made by the stir casting technique. Hardness and tensile strength were two examples of mechanical qualities that have been assessed. Compared to the unreinforced aluminum alloy, the tensile strength of the metal matrix composites was improved by 17.7%, and the hardness increased by 44.1% at a loading of AA6061 (90wt%)/ Al2O3 (5wt%)/Gr (5wt%). A pin-on-disc tribometer was utilized to analyze the dry sliding tribo-behaviors of AA 6061 alloy reinforced with Al2O3 and Gr by varying the applied load and the sliding distance. The wear resistance of aluminum alloy reinforced with Gr (5wt%)/Al2O3(5wt%) increased by 85.0% when the load was applied at 25N compared to unreinforced aluminum alloy, and the frictional coefficient decreased by 58.0%. Additionally, an optical microscope and scanning electronic microscope were used to assess the worn surfaces.

This paper investigated how casting affects ASTM ZA-27 alloy's tribological performance in dry and lubricated conditions. To this end, varying contact loads and sliding speeds were applied to tribological tests. The ZA-27 alloy was produced using gravity die casting (GDC) and new rheocasting (NRC) methods. The results showed that the microstructure of GDC ZA-27 alloy is dendritic containing α and η phases. While the NRC alloy microstructure demonstrates a semi-globular structure of fine equiaxed α phase bordered by eutectoid α and η. The NRC alloy achieved an improvement in tensile, hardness, and elongation properties by almost 15%, 20%, and 25%, respectively. Regarding tribological properties, the NRC alloy achieved an enhancement in tribo-behavior by lowering the coefficient of friction (COF) to about 67% than the GDC alloy. Further, the results showed that the wear rate recorded an increment with applied load for both GDC and NRC alloys. Though, the results showed that the wear rate with NRC alloy was lower compared to the GDC alloy with about 84% at 160N normal load. The worn surfaces of NRC alloys were characterized by smooth and shallow wear grooves. While the GDC alloy worn surfaces were rougher and experience deeper grooves and damage.