Preparation and Characterization of Hollow Glass Microspheres Reinforced Carbon-Epoxy Composite

Abstract

The uses of fillers in composites are creating new opportunities in the composite industry. Hollow Glass Microspheres (HGM) are Soda-lime-borosilicate glass hollow spheres with thin walls used as low-density filler material which can reduce final part weight by up to 15% or more without compromising the mechanical integrity. Glass bubbles take up 20 times the space of normal mineral filler, lowering the cost per unit volume; hence, the need for weightless and high-strength materials for state-of-the-art engineering applications may be met by HGM reinforced composites. Epoxy being a key structural material for marine, automotive and aerospace applications, is known for its brittle nature, poor mechanical and thermal properties and to date, not much work has been done on hollow glass microspheres reinforced carbon epoxy composites, however few systematic studies showing the influence of reinforcements on mechanical and thermal properties of carbon epoxy/HGM composites were conducted. Moreover research on Carbon/Epoxy - Hollow Glass Microsphere composites is limited, this study focuses on it. To study the ramification of low density fillers on physical, thermal and mechanical properties of composites, laminates with Epoxy resin and Carbon fiber reinforcement along with various percentages of the HGM’s 0.2, 0.4, 0.6, 0.8, 1.0 wt. % were fabricated using a 3-axis filament winding machine and cured. The test specimens were cut according to ASTM standard from the unidirectional laminated sheets. The microstructure, thermal and mechanical properties of CE/HGM composites was studied by Field Emission Scanning Electron Microscopy (SEM), Thermogravimetric Analyzer (TGA) and tensile experiment. Microscopic observation indicated agglomerations and some HGM particles stop participating. This restricted the CE/HGM matrix stress transfer and reduced the tensile strength of the composites and also reduced the adhesion interface between the filler and the matrix thereby resulting in low flexural strength. The results indicated that the density decreased with the HGMs content increasing. Hence it can be concluded that, although raw HGM’s were used without any modification, the HGM’s play an far-reaching role in improving the Carbon-Epoxy composites properties, thus showing the suitability of CE/HGM composites as an promising material for defence, aerospace, automobile, applications.