Authors

Abstract

In this study laminate composites were prepared, one was reinforced with three layers of kevlar fibers at (Vf = 17.89%) and the second was reinforced with hybrid laminate with sequence of layers (Kevlar-Glass-kevlar (KGK)) at (Vf = 15.3%), samples were tested before and after silica addition at volume fraction (3%). Tests were (tensile, flexural, impact, hardness, and optical microscope), hand lay-up technique used to prepare samples. Matrix was unsaturated polyester resin. Results showed that mechanical properties (tensile strength, flexural strength, and fracture toughness) decreased after silica addition from (190 MPa, 610 MPa, 35.6 MPa.m1/2 ) to (100.5 MPa, 212MPa, 27.7 MPa.m1/2 ) respectively for composite reinforced with three layers of Kevlar fibers at (Vf = 17.89%) and from (175.5 MPa, 387 MPa, 32.36 MPa.m1/2 ) to (67.6 MPa, 210 MPa, 23 MPa.m1/2 ) respectively for laminate composite with layers (Kevlar-Glass-Kevlar (KGK)) at (Vf = 15.3%). Hardness increased after addition of silica from (79.25 to 81.2) for composite with three layers of Kevlar fibers at (Vf = 17.89%) and from (80 to 82.3) for composite with layers (Kevlar-Glass-Kevlar (KGK)). Optical microscope showed that layers were distributed in matrix and addition of silica leads to delamination of composite after using flexural test.

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