Effect of Nanosilica and Multiwalled Carbon Nanotubes on the Mechanical and Impact Performance of Unidirectional Kevlar/Epoxy Based Composites

Abstract The introduction of numerous nanoparticles into nanotechnology in recent years has opened the door for the incorporation of nanoparticles into polymeric-based composite materials for mechanical improvement. Composite materials are becoming a promising substitute material in the fabrication of numerous components due to their high weight-to-strength ratio and mechanical characteristics such as tensile Strength, flexural Strength, interlaminar shear strength, and impact strength. This research aims to determine the effect of a combined mixture of silica and multiwalled carbon nanotube particles (MWCNT) on the mechanical and impact properties of unidirectional Kevlar (UD)/epoxy composites for use in defence and aerospace applications. The addition of these Nanofillers results in high-performance reinforcement and the formation of hybrid composites with improved properties due to their use. The addition of specific nanomaterials can further enhance these characteristics, dependent on the concentration at which they are introduced into the solution. The most challenging aspects of incorporating nanomaterials into matrix materials are ensuring uniform mixing of the nanomaterials with the matrix material and increasing the viscosity of the matrix material when the nanomaterials are introduced into the matrix. Using different weight percentages, it is possible to determine the optimal ratio of nanofiller for predicting the enhanced mechanical properties of nano-composites. Preparation of the composite with different weight percentages (1 percent and 3 percent) of Nano SiO2 particles mixed with 0.25 percent MWCNT and 6 layers of the UD Kevlar fibre was accomplished using an ultrasonic vibration-assisted hand layup process. Tensile tests, Charpy impact tests, and interlaminar shear strength tests evaluated the material's mechanical properties. Experimental results revealed that tensile strength and impact strength increased by up to 80 percent and 50 percent, respectively, compared to the neat specimens. The ILSS test demonstrates a 271 percent improvement in shear strength at 3 percent and 0.25 MWCNT. The overall results determined that the combination of 3 percent SiO2 and 0.25 percent MWCNT provided the most enhanced mechanical properties while also being the most optimized. This study's findings indicate that applying a nano-silica and MWCNT mixture of Nanofillers to Kevlar fabrics is a promising method for improving a Kevlar-based hybrid composite's mechanical and impact energy absorption laminate.