Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Kevlar fibers

Effect of Silica Powder Addition on Mechanical Properties of Polymer Laminate Composite

F.A. Hashim; M.S. Hamza; R.R. Abdullah

Engineering and Technology Journal, 2017, Volume 35, Issue 7, Pages 737-740

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.

Studying Mechanical Properties For Polymer Matrix Composite Material Reinforced By Fibers And Particles

Engineering and Technology Journal, 2010, Volume 28, Issue 4, Pages 81-93

The work focuses on the preparation of hybrid polymer matrix composite
materials prepared from the unsaturated polyester resin as matrix reinforced by woven
glass fiber kind ( E-glass ) and graphite particles as first group of samples and the second
group of samples reinforced with woven Kevlar fiber kind (49) instead of glass fiber.
This work includes studying the effect of selected volume fractions ( 0% , 5% , 10% ,
15% , 20% ) of graphite particles with mixture of different particle Size of ( 25 μm – 106
μm ) on the properties of the prepared composite materials, Number of mechanical tests
were done,they include (Tensile, Compression, Impact, Flexural Strength, Shear Stress
and Hardness), which done at room temperature Result of the work shows that the
values of (Tensile stress, Tensile elastic modulus, Fracture Toughness, Hardness)
increase with the increase of graphite particle volume fraction for both groups samples.
As well as the values of the (Compression elastic modulus, Flexural strength, Shear
stress) increase with the increase of low values of graphite particles volume fraction for
both groups of samples. Where as the values of Impact strength of the prepared
composite material decreased with the increases of volume fraction of graphite particles
for both group samples. As well the result shows that the values (Tensile stress, Tensile
elastic modulus, impact strength, Fracture toughness) for hybrid composite materials
reinforced by Kevlar fiber are higher than values reinforced by glass fiber instead of
Kevlar fiber, While the values of (Compression stress, Flexural Strength, Shear stress,
Hardness) for hybrid composite materials reinforced by glass fiber are higher than values
reinforced by Kevlar fiber instead of glass fiber.