Experimental study and empirical analyses of abrasive waterjet machining for hybrid carbon/glass fiber-reinforced composites for improved surface quality

Poor surface quality is one of the critical defects after trimming of fiber-reinforced plastic (FRP) composites through both conventional and non-conventional machining processes. With the recent introduction of hybrid composites from different fiber reinforcements, this makes the trimming or cutting of them challenging. Therefore, an experimental study was attempted to elucidate the effect and relationship between the machining parameters in the abrasive waterjet cutting, namely abrasive flow rate, hydraulic pressure, and stand-off distance, and traverse rate on the surface roughness of the machined composites. An optimum setting of machining parameters and mathematical modeling equation were obtained by applying the response surface methodology for improving the surface quality. It is apparent that the abrasive flow rate and stand-off distance contributed the most in affecting the surface roughness of the hybrid FRP composites. The mathematical relationship, which is in the form of quadratic function, has been validated with confirmation test in order to optimize the surface roughness.