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Highlights Owing to the outstanding properties of boron carbide (B4C) particles, material researchers have shown potential in filler‐reinforced polymer composites. The present work studied the implication of B4C fillers on the mechanical and ballistic properties of glass fiber epoxy reinforced composites. Two different weight percentages of 2 and 4 wt% B4C fillers were used to modify the epoxy resin. The composite samples with glass fabric woven were made through compression molding. The results show that the tensile, flexural, interlaminar, impact strength and hardness of glass fiber composite were improved by addition of 2 wt% of B4C. The high‐velocity ballistic tests were conducted on the unfilled and B4C filler‐reinforced composites using a 9 mm parabellum projectile with an initial striking of 372 ± 15 m/s. The least back face signature (BFS) and highest specific energy absorption (SEA) were observed for 2 wt% B4C filler composite. Adding B4C filler enhanced matrix toughening and interfacial bonding between fiber and matrix. Matrix cracking and fiber breakage result in the least ballistic resistance for unfilled composite. Fracture behavior was studied on tensile, impact, and ballistic‐tested samples using scanning electron microscopy. The fractured surfaces of filler‐reinforced composite demonstrated good interfacial bonding, matrix hardening, and fiber pullouts. The addition of B4C with epoxy up to 2 wt% improves the mechanical and ballistic properties of the composites. The least back face signature and highest specific energy absorption were observed for 2 wt% B4C filler composite. B4C filler enhanced matrix toughening and interfacial bonding between fiber and matrix. Failure of unfilled glass fiber composites is a combination of matrix cracking, fiber pullout, and interface debonding. [ABSTRACT FROM AUTHOR]

Composites with excellent flame retardant and mechanical properties are in high demand in the aerospace and various industrial fields. Glass fiber (GF) reinforced polyimide (PI) composites (GFRPCs) were fabricated using a simple ball milling and hot pressing technique. The effect of GF content on the thermal stability, mechanical and flame retardant properties of composites has been systematically studied. The Rockwell hardness of GFRPCs increase with increasing GF content, while the compressive strength, impact strength and flexural strength initially show an increase followed by a decrease due to the excellent dispersibility of the fillers and the strong interfacial interaction between the one‐dimensional GF and PI matrix. Thermogravimetric analysis results show that the addition of GF with very low thermal conductivity and excellent temperature resistance can effectively improve the thermal stability of PI. Adding GF into PI can obviously improve the limiting oxygen index value. Moreover, as the GF content increased, the time to ignition of the composites prolonged while total heat release decreased. These findings suggest a viable solution for enhancing both the flame retardance and mechanical properties of PI‐based composites. Highlights: GFRPCs with high GF content fabricated via ball milling‐hot pressing method.Silane modified GF obviously improves the thermal stability of PI matrix.GFRPCs‐28 exhibits superior mechanical properties.An increases in time to ignition (TTI) and mass residual rate (MRR) of the GFRPCs was observed on adding GF. [ABSTRACT FROM AUTHOR]

This study investigates the influence of reduced graphene oxide (rGO) coated glass fabrics on the strain sensing and the mechanical characteristics of fiber‐reinforced composites. Graphene oxide was applied in two thicknesses (threefold and fivefold coatings) onto a fabric using a padder mangle machine followed by thermal reduction and infused with an epoxy to manufacture rGO‐enhanced composite. The tensile modulus and flexural strength of the rGO‐enhanced composites with threefold coating were improved by 27% and 6.2%, respectively, compared with the equivalent composite manufactured without rGO. The normalized resistance (ΔR/R0) of composites increased by 0.89% and 3.48% under a cyclic tensile force of 1000 and 4000 N. The magnitude of ΔR/R0 was stable within 30 cycles suggesting a consistent strain sensing performance with a gauge factor of 15.55. The electrical response of the rGO‐enhanced composite was evaluated using a new industrial standard for sensors, by assessing calibration curves. The composite showed low hysteresis and low electrical viscosity which make these materials suitable for industrial piezoresistive strain sensors. [ABSTRACT FROM AUTHOR]

Polyamide (PA) is the mostwidely used type of semi‐crystalline polymer among engineering plastics, with its low density and high mechanical properties. But the high moisture absorption of PA6 limits its use in some areas. Blending and the addition of reinforcement can decrease the moisture absorption value of PA6. In this research, the PA6/PA610 blends and glass fiber (GF) reinforced PA6/PA610 composites were fabricated, and the features of these blends‐composites were examined. The blends and composites were produced by using extrusion and injection molding methods and characterized by water absorption (WA) test, tensile test, scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), thermogravimetric analysis, and differential scanning calorimetry (DSC). The loading rates of GF were used as 10–20‐ 30–40 wt%. According to the tensile test consequences, the highest increase in the tensile strength for the composites was observed at 30% GF ratio. DMA results demonstrated an increase in loss modulus and storage with the increasing fiber amount. It is observed that the WA value of neat PA6 was diminished by blending with PA610 and adding an increasing amount of GF. [ABSTRACT FROM AUTHOR]

Due to environmental issues and high cost of synthetic fibers, natural or cellulosic fibers have emerged as a promising reinforcement for polymer composites. The hybridization of natural fiber with synthetic fiber is a useful technique to improve the mechanical properties instead of using the natural fibers alone. This research aims to evaluate the influence of glass fiber hybridization on the mechanical properties of continuous, unidirectional, alkali (NaOH)‐treated kenaf‐epoxy composites. At first, the effect of treatment of various concentrations (3, 5, 7, and 9% w/v) of NaOH on the structure of single kenaf fiber was characterized using XRD, SEM, FTIR, and tensile testing. At the optimum 5% alkali concentration the tensile strength, modulus, and %elongation of the kenaf fibers were enhanced by 81%, 114%, and 42%, respectively. The effect of hybridization of 5% NaOH treated kenaf along with glass fiber on the improvement in tensile, flexural, and impact properties for hand laid kenaf‐glass‐epoxy hybrid composite laminates was established. The overall matrix to fiber weight ratio of five different layup sequence laminates was maintained constant at 70:30. It can be concluded from the obtained results that the 15% glass and 15% kenaf fiber hybridized composites exhibited the maximum increment in tensile strength and modulus (68.5% and 19.5%, respectively) in comparison to the unhybridized composites. Further, the flexural strength and modulus were also improved by 21% and 67%, respectively, and the impact strength by 153%. The SEM fractography proved that alkali treatment of fibers improved the fiber‐matrix interfacial bonding whereas fiber breakage, fiber pull‐out and debonding were established as the main fracture mechanisms of hybrid composites. The findings of the present investigation on kenaf‐glass hybrid composites corroborate that they are suitable for secondary structural applications in construction and automobile sectors. [ABSTRACT FROM AUTHOR]

Steel fiber is the most common metal fiber used due to its cost‐effectiveness, high performance, and availability despite its heavyweight. This study is an attempt to evaluate the mechanical properties of steel/glass fiber and steel/basalt fiber‐reinforced epoxy composites. The symmetric hybrid laminates were produced by replacing the innermost 1, 2, 3, and 4 layers of steel fiber (200 mesh size) with basalt and glass fiber layers. The specimens were subjected to tensile, flexural, and Charpy impact tests in accordance with relevant ASTM standards. Moreover, fracture surfaces were analyzed, and the micrographs were obtained using a scanning electron microscope. The results showed that a high improvement in tensile strength was achieved with BS1–E (1 layer steel mesh–8 layers basalt) and GS1–E (1 layer steel mesh–8 layers glass) hybrid composites, with an increase of 528% and 233%, respectively, compared to steel fiber reinforced epoxy composites. Similarly, BS1–E and GS1–E hybrid composites showed the highest flexural strength increase of 82.2% and 66.8%, respectively, compared to steel fiber reinforced epoxy composites. Consequently, the potential to hybridize steel fiber with glass fiber and basalt fiber could create new materials with unique physical structures and synergistic effects on mechanical properties. [ABSTRACT FROM AUTHOR]

Glass fiber (GF) reinforced nylon56 composites (nylon56/GF) were prepared by melting and blending through twin‐screw extruder with continuous fiber feeding. The structure and properties of the composites were characterized by electron density tester, polarizing microscope, scanning electron microscope, electro‐mechanical universal testing machine and thermal analyzer. The results showed that the density of the prepared composites is less than 1.37 g/cm3. There is strong interface adhesion between glass fiber and nylon56 matrix in the composite system, and the glass fiber length in the system is 0.47–0.61 mm. With the increase in the content of high‐performance glass fiber, the mechanical properties of the composite are significantly improved. When four bundles of GF are added, the properties of the nylon56/GF composite are the best. The tensile strength of nylon56/GF composite reaches 160 MPa, 86.9% higher than that of nylon56. The bending strength is 180 MPa and increases by 98.7% more than that of nylon56. The flexural modulus is 7100 MPa and rises by 125.6% compared with nylon56, and the impact strength is 11 kJ/mm2, which is 307.4% higher than that of nylon56. The nylon56/GF composite has a low density and excellent performance and can be widely used in locomotive and wind power. [ABSTRACT FROM AUTHOR]

This research article presents the comparative investigation of physical, mechanical, and abrasive wear behavior of chopped glass and basalt fiber‐reinforced epoxy composites. The composites were fabricated by hand lay‐up technique. The fiber (glass and basalt) was varied in the range of 10 to 40 wt.% in the composite at an interval of 10 wt.% to find out the physical (density and void content), mechanical (tensile strength, flexural strength, and impact strength), and steady state abrasive wear rate, respectively. The Taguchi's design of experiment method was used for designing of experimental runs having input controlling variables like sliding distance, normal load, fiber content, and abrasive size. This study clearly demonstrated that with increase the fiber content, the density and void content of both fiber (glass and basalt) reinforced composite were increased. The basalt fiber‐reinforced composites show lesser voids than glass fiber‐reinforced composites. The tensile strength, flexural strength, and impact strength of both composites increased with increase the fiber content whereas glass fiber‐reinforced composites show slightly lower tensile strength, flexural strength, and impact strength than basalt fiber‐reinforced composites. However, as far as basalt fiber‐reinforced composites show better wear resistance than glass fiber‐reinforced composites. [ABSTRACT FROM AUTHOR]