This review paper initially summarizes the latest developments in impact testing on polymer matrix composites collating the various analytical, numerical, and experimental studies performed since the year 2000. Subsequently, the scientific literature investigating nanofiller reinforced polymer composite matrices as well as self-healing polymer matrix composites by incorporating core-shell nanofibers is reviewed in-depth to provide a perspective on some novel advances in nanotechnology that have led to composite developments. Through this review, researchers can gain a representative idea of the state of the art in nanotechnology for polymer matrix composite engineering, providing a platform for further study of this increasingly industrially significant material, and to address the challenges in developing the next generation of advanced, high-performance materials.

This article investigates the impact of manufacturing technology on the structure, mechanical, and tribological properties of new antifriction composite materials based on R6M5 high-speed tool steel grinding waste. The characteristics of the new composite’s structure formation and its impact on properties after use of the established technological modes, including grinding waste regeneration, were illustrated. It was demonstrated that such technology is capable of ensuring microheterogeneous structure. The material’s structure consists of the metal matrix based on R6M5 high-speed tool steel waste and uniformly distributed CaF₂ solid lubricant in the steel matrix. As compared to known iron-based composites, this structure promotes a high degree of mechanical and tribological properties. During tribological tests, anti-seize thin films of 15–20 μm are formed on the contacting surfaces. These constantly renewable films contribute to the high antifriction properties of the composite under the studied friction conditions and provide a self-lubricating effect. Such films fully cover both the material’s surface and the counterface. The formation of antifriction films results in the self-lubrication mode. The findings of the study open up the possibility of predicting the friction behavior of a composite at high temperatures by selecting the initial metal grinding waste to ensure the appropriate level of properties. The extensive use of various alloy steel-based industrial grinding waste in the re-production cycle would significantly contribute to resolving the global environmental problem of protecting the environment from pollution.

Composite laminates are made of glass woven roving mats of 610gsm, epoxy resin and nano clay which are subjected to projectile impact. Nano clay dispersion is varied from 1% to 5%. Impact tests are conducted in a gas gun setup with a spherical nose cylindrical projectile of diameter 9.5 mm of mass 7.6 g. The energy absorbed by the laminates when subjected to impact loading is studied, the velocity range is below ballistic limit. The effect of nano clay on energy absorption in vibration, delamination and matrix crack is studied for different weight % of nano clay and for different thickness values of the laminates. The natural frequencies and damping factors are obtained for the laminates during impact and the effect of nano clay is studied. The results show considerable improvement in energy absorption due to the presence of nano clay

A comparative study has been made for micro-scribing of copper and aluminum thin films in air and underwater using 355nm, 532nm and 1064nm wavelengths of a Q-switched Nd³⁺: YAG laser with 6ns pulse duration. For aluminum in air medium, the channel depth obtained is high for 355nm wavelength, whereas for copper coated on a polyimide substrate, 532nm wavelengths produced higher depth. In underwater scribing, with increase in the pulsed laser energy, the depth of micro channel was increased and remained unchanged at higher energy. The influence of beam profile on the micro channel cross-section has also been discussed. Further, theoretical modeling of the laser-material interaction in air and underwater ambience conditions to estimate the recession rate has been discussed by incorporating the laser ablation temperature measured using the laser induced breakdown spectroscopy technique.

The aim of this paper is to investigate mechanical and frictional properties of natural rubber/styrene butadiene rubber (NR/SBR) blends with and without silicon nitride (Si₃N₄) filler. The rubber is surface modified by silane coupling agent (Si-69) for enhancing hydrophobic property. The Si₃N₄of percentage 0 1, 3, 5 and 7, is incorporated into NR/SBR rubber compounds with 20% precipitated silica. The specimens with and without fillers are prepared as per standard for tensile and friction testing. Fourier transform infrared (FTIR) spectroscopy test is conducted and it is inferred that the coupling agent is covalently bonded on the surface of Si₃N₄ particles and an organic coating layer is formed. The co-efficient of friction and specific wear rate of NR/SBR blends are examined using an in-house built friction tester in a disc-on-plate (DOP) configuration. The specimens are tested to find coefficient of friction (COF) against steel grip antiskid plate under dry, mud, wet and oil environmental conditions. It is found that the increase in tensile strength and modulus at low percentage of Si3N4 dispersion. It is also observed that increase in sliding friction co-efficient and decrease in wear rate for 1% of Si₃N₄ dispersion in NR/SBR blends. The friction tested surfaces are inspected using Scanning Electron Microscope (SEM) and 3D non contact surface profiler.