Abstract
Epoxy glass fiber laminate composite (PMCs) are finding ever increasing applications in aerospace and automobile industries due to its high strength to weight ratio and resistance to aqueous environment. Additions of particulate reinforcements in the polymer matrix are reported to improve the Interlaminar Shear Strength and Interlaminar Fracture Toughness of the composites. In the present investigation, epoxy glass fiber laminate composites were processed using hand layup and vacuum bagging technique. The particulate reinforcement precipitator fly ash (25 - 45 μm) was added in the epoxy matrix by mechanical mixing up to 10 wt%. The effects of fly ash reinforcement on the mechanical properties and Interlaminar Fracture Toughness were studied before and after exposure to aqueous fog in a salt fog chamber at 45°C. In unexposed condition Mode I interlaminar fracture toughness of epoxy glass fiber laminate composite improved by the addition of fly ash reinforcement 10% (By weight) by 49.43% and when it was subjected to aqueous fog for 10 days the interlaminar fracture toughness improved 58.42%. Exposure to aqueous fog for 10 days causes plasticization of resin matrix and weakening of fiber/matrix interface results in improvement in interlaminar fracture toughness. The fracture surfaces were analyzed using scanning electron microscopy.
Highlights
Polymer matrix composites (PMCs) are extensively used for light weight structures where a high specific stiffness, strength and corrosion resistance is required
Addition of particulate reinforcement is reported to alter the kinetics of moisture uptake which is expected to be further enhanced in the case of fly ash addition as reinforcement
It is important to study the effect of exposure to moisture on the delamination characteristics indicated by the interlaminar fracture toughness (GIC)
Summary
Polymer matrix composites (PMCs) are extensively used for light weight structures where a high specific stiffness, strength and corrosion resistance is required. The kinetics of moisture absorption and its effect on mechanical properties must be understood when designing components and structures made of PMCs [1]. Various researchers have studied the effect of particulate (polymer/elastomer) addition on the kinetics of moisture absorption and on mechanical properties [2]-[5]. Addition of particulate reinforcement is reported to alter the kinetics of moisture uptake which is expected to be further enhanced in the case of fly ash addition as reinforcement. Moisture uptake can influence the tensile strength and interlaminar fracture toughness (GIC) of such composites. Delamination is the major mechanism contributing to the interlaminar fracture in PMCs. It is important to study the effect of exposure to moisture on the delamination characteristics indicated by the interlaminar fracture toughness (GIC).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have