Mechanical and machining performance of glass and coconut sheath fibre polyester composites using AWJM

This paper aims to address the responses of the AWJM parameters to two different reinforcement sources, viz, bi-directional glass mat (synthetic) and coconut sheath (natural) fibre, in a polymer matrix composite. The machining quality of the cut (kerf taper angle and surface roughness) was analysed, using the multi-objective response based on the L-9 (3(4)) orthogonal array, using the Taguchi-based experimental grey relational analysis. The mechanical performance of the composites was studied before and after machining, to observe the interfacial adhesion between the fibre and the matrix due to the cutting force, using scanning electron microscopy (SEM). Only very little reduction in tensile strength was found after the machining of the composite in each case, and it indicates lesser stress formation due to the cutting forces. The machining performance of two different composite materials with the same wt % of fibre content was found experimentally; it showed significant changes in the results for both the materials. However, the abrasive particle size was identified as the most significant parameter influencing the quality of the cut in both the composites. A higher crack resistance was found in the glass mat composites due to their better interfacial adhesion capability.