Natural fiber is often considered to be deficient for high-performance reinforcement of polymer matrix composites. However, the environmental aspects of natural fiber are attractive to many researchers in the area of natural composites because of the specific strength and eco-friendly properties of natural fibers. In this research, alkali-treated natural fibers are chopped neem fibers, and bidirectional woven mat was used as reinforcement and blended with epoxy matrix. Also, sawdust cellulose was used as a filler material to fabricate composite laminates by the conservative hand layup method. The composite laminates are varied by different weight fractions of reinforcement (25 %), epoxy matrix (70 %), and filler (5 %). Then, to quantify the effect of storage modulus, loss modulus and the damping factor of the hybrid composites are taken by conducting dynamic mechanical analysis. Maximum storage modulus is 1,343 MPa. The results show that increasing the bidirectional woven fiber loading will give 61 % more stiffness in the elastomeric region when compared to chopped neem fiber loading in the hybrid composites, and analyses of the crystallinity effects by x-ray diffraction also identify the adhesion quality between the fibers, fillers, and matrix by using the surface morphology test scanning electron microscopy of the hybrid composites.

Natural fiber-reinforced hybrid composites are prime focus materials for numerous engineering applications. In this research work, chopped neem (Azadirachta indica) fibers and bidirectional banyan (Ficus benghalensis) woven fabric-reinforced epoxy hybrid composites were fabricated using the conventional hand lay-up technique. Two fibers, namely chopped neem fiber and woven banyan fiber, were stacked in three different sequences. The weight fraction of these two fibers was varied to quantify the strength of the hybrid composite. The mechanical properties, such as tensile, compression, and impact tests, were carried out to quantify the effect of the fiber weight fraction and the stacking sequence of fiber on the strength of the hybrid composite. The increase in 9 % woven banyan fiber weight fraction has a positive influence on the tensile and compressive strengths of the natural fiber-reinforced hybrid composites. Further, the stacking sequence of these two fibers has significant influence on the compressive strength of the hybrid composites. The impact energy absorption capacity of the hybrid composite is more significantly increased with an increase in the 9 % chopped neem fiber weight fraction than with an increase in the banyan fiber weight fraction. The scanning electron microscopy surface morphological analysis revealed the dominant mode of failure in the hybrid composites.

Numerous countries are investigating alternative fuel sources in response to the escalating issue of energy inadequacy. Using environmentally sustainable biodiesel as a potential alternative to fossil fuels, particularly from waste sources, is a developing prospect. This study aims to examine the feasibility of utilizing industry leather waste as a diesel fuel substitute. Traditional transesterification was used to obtain methyl ester out of leather waste. After processing, 81.93% of methyl ester was produced. Bio-silica (Bio-Si) is used as a fuel additive to enhance combustion and decrease emissions. This work utilized a leather industry waste fat biodiesel (LIWFB), LIWFB blend (B50), LIWFB blend with Bio-Si nanoparticles (B50Bio-Si50, B50Bio-Si75, and B50Bio-Si100 ppm) to analyze the engine outcome parameters at standard operating conditions. Experimental results revealed that adding Bio-Si in the biodiesel blend increased thermal brake efficiency (BTE) but was lower in diesel fuel. The biodiesel blends reduced NOx emissions more than Bio-Si nanoparticle blends. Furthermore, the smoke opacity was reduced by 31.87%, hydrocarbon (HC) emissions were reduced by 34.14%, carbon monoxide (CO) emissions were decreased by 43.97%, and oxides of nitrogen (NOx) emissions were slightly increased by 4.45% for B50Bio-Si100 blend compared to neat diesel. This investigation determined that all the emissions remained lower for all combinations than neat diesel, with a small increase in NOx emissions. Therefore, the LIWFB blend with Bio-Si nanoparticles was a viable diesel fuel alternative in diesel engines.

Thermal insulation materials are used to increase the efficiency of many structural and heat-resistant applications. A sawdust-filled alkali-treated Neem/Banyan hybrid composite is prepared and its behaviors of thermal stability, short-term heat resistance, thermal expansion, and thermal conductivity are examined by conducting Thermogravimetric Analysis (TGA) and a thermal conductivity test. The hybrid composite is prepared by hand layup technique, using an epoxy matrix blended with sawdust as the matrix and varying the weight fraction of the Neem/Banyan fibers as reinforcement for fabrication of hybrid composites. The weight fractions of five composite samples of Neem/Banyan fibers are 90/45, 90/60, 45/45, 60/90, and 45/90 (in grams), respectively. The mass loss of fabricated composite laminates due to temperature has been investigated through TGA. Sample A gives an initial deformation from a mass of 11 mg to 10.9 mg at a 330°C temperature and a maximum working temperature of 427°C during mass at 25 % of hybrid composites. The material can withstand up to 25 % of the mass of the hybrid composite after this mass of 2.75 mg moves to degrade hybrid composites. Therefore, the percentage efficiency of the hybrid composite is 75 % of the mass, giving working conditions of hybrid composites.

This work mainly focuses on increasing the mechanical strength and improving the corrosion resistance of an aluminum alloy hybrid matrix. The composites are prepared by the stir casting procedure. For this work, aluminum alloy 8079 is considered as a base material and titanium nitride and zirconium dioxide are utilized as reinforcement particles. Mechanical tests, such as the ultimate tensile strength, wear, salt spray corrosion test and microhardness test, are conducted effectively in the fabricated AA8079/TiN + ZrO₂ composites. L9 OA statistical analysis is executed to optimize the process parameters of the mechanical and corrosion tests. ANOVA analysis defines the contribution and influence of each parameter. In the tensile and wear test, parameters are chosen as % of reinforcement (3%, 6% and 9%), stirring speed (500, 550 and 600 rpm) and stirring time (20, 25 and 30 min). Similarly, in the salt spray test and microhardness test, the selected parameters are: percentage of reinforcement (3%, 6% and 9%), pH value (3, 6 and 9), and hang time (24, 48 and 72 h). The percentage of reinforcement highly influenced the wear and microhardness test, while the stirring time parameter extremely influenced the ultimate tensile strength. From the corrosion test, the hang time influences the corrosion rate. The SEM analysis highly reveals the bonding of each reinforcement particle to the base material.

Awareness of environmental concerns influences researchers to develop an alternative method of developing natural fiber composite materials, to reduce the consumption of synthetic fibers. This research attempted testing the neem (Azadirachta indica) fiber and the banyan (Ficus benghalensis) fiber at different weight fractions, under flame retardant and thermal testing, in the interest of manufacturing efficient products and parts in real-time applications. The hybrid composite consists of 25% fiber reinforcement, 70% matrix material, and 5% bran filler. Their thermal properties—short-term heat deflection, temperature, thermal conductivity, and thermal expansion—were used to quantify the effect of potential epoxy composites. Although natural composite materials are widely utilized, their uses are limited since many of them are combustible. As a result, there has been a lot of focus on making them flame resistant. The thermal analysis revealed the sample B was given 26% more short-term heat resistance when the presence of banyan fiber loading is maximum. The maximum heat deflection temperature occurred in sample A (104.5 °C) and sample B (99.2 °C), which shows a 36% greater thermal expansion compared with chopped neem fiber loading. In sample F, an increased chopped neem fiber weight fraction gave a 40% higher thermal conductivity, when compared to increasing the bidirectional banyan mat of this hybrid composite. The maximum flame retardant capacity occurred in samples A and B, with endurance up to 12.9 and 11.8 min during the flame test of the hybrid composites.