The present study focuses on the fabrication and analysis of thermal and dynamic mechanical properties of epoxy bio-composites reinforced with 15 wt.% sisal fibers and varying carbon nanotube (CNT) content (0–2.0 wt.%). As per the results, incorporation of 1.0 wt.% CNT significantly enhances thermal and mechanical properties of the composite. Compared to the baseline composite without CNTs, thermal degradation onset has been improved by approximately 13%, while crystallinity and thermal resilience also increased. The storage modulus and loss modulus rose by approximately 79% and 197% respectively, indicating greater stiffness and energy absorption capacity. The damping factor (tan δ) decreased by over 56%, implying enhanced load-bearing capability with reduced energy dissipation. These improvements are attributed to better interfacial bonding and uniform CNT dispersion at 1.0 wt.%. The SEM analysis of epoxy bio-composites also revealed that the optimal dispersion and strong interfacial bonding are achieved at 1.0 wt.% CNT. Overall, the findings demonstrate that optimal thermal stability and viscoelastic properties occur at low CNT content in natural fiber composites, making them suitable for advanced structural applications in automotive, aerospace, and packaging sectors.

The effect of the interaction between silica (nS) and hydroxyapatite (nHap) nanomaterials on the characteristics of unidirectional glass-fiber-reinforced epoxy (GF/Ep) composite systems is investigated in this work. The goal of the study is to use these nanofillers to improve the microstructure and mechanical characteristics. Pultrusion was used to produce hybrid nanocomposites while keeping the GF loading at a consistent 75% by weight. The hybrid nanocomposites were made with a total filler loading of 6 wt.%, including nHap, and a nS loading ranging from 2 to 4 wt.%. The mechanical performance of the composite was greatly improved by the use of these nanofillers. Compared to neat GF/Ep, hybrid nanocomposites with 6 wt.% combined fillers exhibited increased hardness (14%), tensile strength (25%), interlaminar shear strength (21.3%), and flexural strength (33%). These improvements are attributed to efficient filler dispersion, enhanced fiber-matrix adhesion, and crack propagation resistance. Incorporating 4 wt.% nS alone improved hardness (6%), tensile strength (9%), tensile modulus (21%), interlaminar shear strength (11.4%), flexural strength (12%), and flexural modulus (14%). FTIR analysis indicated Si-O-Si network formation and increased hydrogen bonding, supporting enhanced interfacial interactions. Ultraviolet reflectance measurements showed increased UV reflectivity with nS, especially in hybrid systems, due to synergistic effects. Impact strength also improved, with a notable 11.6% increase observed in the hybrid nanocomposite. Scanning and transmission electron microscopy confirmed that the nanofillers act as secondary reinforcements within the matrix. These hybrid nanocomposites present a promising material choice for various industries, including marine structural applications and automotive components.

Aluminium alloy based composites are employed in numerous applications that require outstanding performance due to their superior mechanical characteristics, including higher strength, stiffness, and wear resistance. They are used in engine parts like pistons and connecting rods to improve performance and durability. In this work, Al7075 is employed as the matrix material. Aluminium oxide particulates were chosen as the reinforcing particles. The Al7075–6%Al₂O₃ composites were manufactured using the stir casting technology. Scanning electron microscopic instrument was employed to investigate the microstructure of Al7075–6%Al₂O₃ composites. The microstructure analysis of Al7075–6%Al₂O₃ composites revealed the even dispersion of Al₂O₃ particulates throughout the Al7075 matrix. The Pin on disc apparatus was utilized to conduct a wear experiment on Al7075–Al₂O₃ composites. Taguchi methodology was employed to optimize the wear process factors of the produced composites for enhanced performance. According to ANOVA outcomes, the most impacting factor was the sliding distance 87.057% then speed 7.165% and lastly load 0.435%. The R-Sq value and R-Sq (adj) value for wear response obtained using Minitab 16 Taguchi software are 95.05% and 92.08% respectively. The delta values for load, speed and sliding distance are 0.668, 2.830 and 10.734 respectively. The results of this demonstrated that the factor that has the greatest impact is sliding distance. The wear response values provided by OA experimental and regression equation are 3.6131 × 10⁻³ mm³/m and 3.3062 × 10⁻³ mm³/m respectively. A difference of 8.49% between the experimental and Taguchi analysis value gives the maximum permissible difference.

In the present study, the influence of the addition of copper (Cu) on the wear behavior of a Al-12.6Si eutectic alloy developed using the spray forming (SF) method was discussed, and the results were compared with those of as-cast (AC) alloys. The microstructural features of the alloys were examined using both optical and the scanning electron microscopy, and the chemical composition and phase identification were achieved by X-ray diffraction (XRD) analysis. The results revealed that the microstructure of binary the SF alloy consisted of fine primary and eutectic Si phases, evenly distributed in the equiaxed α-Al matrix, whereas the Cu-based SF ternary alloy consisted of uniformly distributed fine eutectic Si particulates and spherical-shaped θ-Al₂Cu precipitates, uniformly distributed in α-Al matrix. In contrast, the AC ternary (Al-12.6Si-2Cu) alloy consisted of unevenly dispersed eutectic Si needles and the coarse intermetallic compound θ-Al₂Cu in the α-Al matrix. The addition of Cu enhanced the micro hardness of the SF ternary alloy by 8, 34, and 41% compared to that of the SF binary, AC ternary, and binary alloys, respectively. The wear test was conducted using a pin-on-disc wear testing machine at different loads (10–40 N) and sliding velocities (1–3 ms⁻¹). The wear tests revealed that SF alloys exhibited an improved wear behavior in the entire applied load and sliding velocity range in comparison to that of the AC alloys. At a load of 40 N and a sliding velocity of 1 ms⁻¹, the wear rate of the SF2 alloy is 62, 47, and 23% lower than that of the AC1, AC2, and SF1 alloys, respectively. Similarly, at a sliding velocity of 3 ms⁻¹, the wear rate of the SF2 alloy is 52%, 42%, and 21% lower than that of the AC1, AC2, and SF1 alloys, respectively. The low wear rate in the SF2 alloy was due to the microstructural modification during spray forming, the precipitation of fine Al₂Cu intermetallic compounds, and increased solid solubility. The SF alloys show an increased transition from oxidative to abrasive wear, while the AC alloys demonstrate wear mechanisms that change from oxidative to abrasive, including delamination, with an increase in sliding velocity and load.