Over a past few decade there have been extensive research noted on fiber reinforce polymer matrix COMPOSITES, moreover in recent years there has been remarkable study on natural fiber polymer matrix COMPOSITES due to its capability to sustain against the synthetic fibers and conventional materials. This helps in achieving more desirable material properties for an existing application. In line with this in the present study the composite with the treated and untreated hemp – cotton hybrid mat and epoxy resin prepared with hand layup compression moulding technique. The prepared COMPOSITES were tested for the tensile strength, flexural strength, impact strength and hardness using American society of testing and materials (ASTM) standards. The test results reveals that the treated fiber COMPOSITES exhibits significant increase in the tensile strength and hardness while there was a reduction in flexural strength. The focus of the study was to compare the mechanical properties of these COMPOSITES with the various materials to identify which materials could completely or partially replaced.

The principal effects of mass degradation on polymer matrix COMPOSITES (PMCs) are the decay of mechanical properties such as strength, elongation, and resilience. This degradation is a common problem of the PMCs under thermal cycling conditions. In this article, composite degradation was investigated by measurement of total mass loss (TML) using the Taguchi approach. Thermal cycling tests were performed using a developed thermal cycling apparatus. Weight loss experiments were performed on the glass fiber/epoxy laminates under different number of thermal cycles and temperature differences. Also, The specimens had various fiber volume fractions and stacking sequences. Statistical analysis is performed to study contribution of each factor. Based on weight loss rates, a regression model was presented to evaluate the TML of laminated composite materials samples. It was found that the temperature differences and fiber volume fraction are the most effective factors of SURFACE degradation with 61 and 22 percent contribution. Also, under the similar experimental conditions, the [0]8 layups exhibits 44 and 35.7 percent more mass loss than the [0.±45.90]s and [02.902]s layups, respectively.

Nowadays, with the expanded radar (Radio Detection and Ranging) systems, the investigation of various materials with the capability to reduce or block reflected electromagnetic radiation has developed sharply. In this study, graphene quantum dots-decorated metal-oxide magnetic COMPOSITES were fabricated as electromagnetic absorber materials because of their light weight, and good electric and magnetic properties. Furthermore, to investigate morphology engineering, a hydrothermal route was applied to fabricate nanostructures. Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and elemental mapping (EDS-mapping). Also, the magnetic moment and electromagnetic interference shielding were tested by Vibrating-sample magnetometer (VSM) and reflection loss (RL), respectively.  

Hypothesis: Polymer matrix COMPOSITES (PMCs) have various structural applications. To improve the mechanical properties of PMCs, nanoparticles are usually added to polymer matrix as reinforcements to produce polymer matrix nanoCOMPOSITES. This research investigates the effects of SURFACE treatment of graphene nanoplatelets (GNPs) on the tensile and impact behavior of basalt fibers\ epoxy COMPOSITES. Methods: For this purpose, SURFACE treatment of GNPs was performed using (3-aminopropyl) trimethoxysilane. The presence of silicon and nitrogen elements, which are the main components of functionalization group on the SURFACE of treated GNPs, was confirmed by EDX-SEM mapping analysis. The nanoCOMPOSITES with different weight percentages of treated GNPs (0. 2, 0. 3, 0. 4 and 0. 5) were fabricated by hand lay-up method. Also, two composite samples, one without GNPs and the other with 0. 4 wt% untreated GNPs were fabricated to compare with those reinforced with treated GNPs. Tensile and Charpy impact tests were performed on fully cured samples. Findings: The results showed 21. 1, 3. 6, 35. 1 and 74. 6 percent increase in tensile strength, modulus of elasticity, fracture energy and impact strength, in the order given, for nanoCOMPOSITES reinforced with 0. 4 wt% treated GNPs were obtained compared to those without GNPs. Also, 52. 1, 37. 5, 57. 9 and 25. 5 percent decrease in properties, in the stated order, were observed for nanoCOMPOSITES with 0. 4 wt% of untreated GNPs compared to those without GNPs. According to the SEM images, the increase in tensile properties could be related to the improvement in the adhesion between basalt fibers and epoxy resin, and also the toughening mechanism of treated GNPs. The SURFACE treatment increased the interaction between the GNPs and the matrix, and also the presence of treated GNPs promoted crack deflection phenomenon that is one of the major toughening mechanisms of GNPs. The reduction in the mechanical properties of sample containing 0. 4 wt% untreated GNPs was attributed to the uneven dispersion of GNPs in the epoxy matrix and the weak interactions between the graphene nanoplatelets and matrix and fiber.

This review paper deals with the friction stir processing (FSP) for manufacturing of metal-matrix COMPOSITES (MMCs) based on the Mg-8Al-0.5Zn (AZ80) magnesium alloy. Accordingly, the reported investigations on the AZ80 SURFACE COMPOSITES with various reinforcements, including the carbon nanotubes (CNTs), high-entropy alloys (HEAs), hybrid reinforcements, and composite plates, were summarized. Accordingly, the effects of introducing the second-phase particles, tool rotation rate, tool traverse speed, tool design, and vibration were considered. In this regard, the grain refinement by dynamic recrystallization (DRX) and Zener pinning effect, the uniformity of the particle distribution and avoiding agglomeration, and improvement of mechanical properties and wear behavior were critically discussed. Moreover, useful suggestions for future works were proposed, including focusing on the common reinforcing phases and processing parameters, tensile testing to evaluate the strength-ductility balance, metal additive manufacturing processes, and the correlation of DRX grain size with the Zener–Hollomon parameter similar to hot deformation studies.