Mechanical and wear behavior of gfrp based composites

Abstract

A Study is made of the mechanical and wear behavior of polymer composite reinforced with the glass fiber and filler particles to the epoxy matrix. It is suitably fabricated to the dimensions of 300 mm × 300 mm × 3 mm using hand lay-up technique. The tensile strength of the composites was determined using with a computerized Universal Testing machine as per ASTM 3039 standard procedures at a cross head speed of 5 mm/min. The flexural tests were performed on Universal Testing machine, using the three point bending fixture according to ASTM D790. The impact strength of the samples is measured using an Izod impact test machine as per ASTM 256. The wear test is also performed as per ASTM G99 using pin on disc apparatus in dry sliding conditions for the various compositions of all the three fillers added GFRP composites. The hardness values were also measured using micro hardness measuring machine to support the objective. The test results are found to demonstrate that the tensile and the flextural strength properties are more affected to the percentage of filler addition in the matrix. It is minimum for the sample with GST 2% consisting 6% wt of total fillers the tensile strength of around 265 MPa and flexural strength is about around 361 MPa respectively. Similarly the sample GST 7% attains the tensile strength, flexural strengths are around 370 MPa and 571 MPa respectively. However the sample GST 5% still reaches to an appreciable magnitude in tensile strength of 382 MPa, the flexural strength is 449 MPa. The mechanical strength increases up to GST 5% and remains steady for GST 7% samples, beyond which it decreases drastically, because of the decrease of wettability with respect to the increase in the weight percentage of filler content. The impact strength and micro hardness values also support the same. The reason behind this is the poor adhesion in inter bonding between the reinforcements and matrix, hence poor load bearing capability. This type of non-admissible effects are more for mechanical properties rather than wear properties. Even though the samples prepared and tested in different compositions, the mechanical strength was appreciably good only for the few compositions, particularly for the three filler added (GST) samples. Because of this reason, only those composition samples were taken for wear studies. But their results also proved their superior wear characteristics in particular for the GST 2%, GST 5% and GST 7% samples. The specific wear rate value drops to 0.79 × 10-6 (N-m/ mm3 ) at 20 N load at 2 m/s velocity for the GST 5% specimen. The maximum value of the specific wear rate at 30N load, 1m/s velocity is 9.72 × 10-6 (N-m/ mm3 ) for GST 2% specimen that also contains Graphite, SiC and TiO2 particles each 2 % of them in the composite specimen. newline