Effects of processing parameters on kerf characteristics and surface integrity following abrasive waterjet slotting of Ti6Al4V/CFRP stacks

Experimental data is presented in this paper relating to kerf characteristics and surface integrity when using abrasive waterjet slotting of Ti6Al4V/CFRP stacks with various processing conditions. The effect of typical parameters including traverse speed, hydraulic pressure, stand-off distance and stack configuration on machined quality was also studied. A full factorial experimental array was employed involving 16 trials. The statistical significance of individual processing parameter was determined using analysis of variance method. Results showed that lower level of traverse speed and higher hydraulic pressure were preferred to minimize taper angle. Negative taper angle was recorded on CFRP laminate when cutting stacks with Ti6Al4V/CFRP configuration. Typical kerf profile featured with X shape was generated when cutting stacks with Ti6Al4V/CFRP configuration, while it formed V shape when cutting CFRP/Ti6Al4V stack. Ti6Al4V/CFRP configuration was preferred during abrasive waterjet slotting in order to minimize barrel error variation (down to 1 μm) between CFRP and Ti6Al4V. Ridges, delamination, strip marks and craters were observed on most of the machined CFRP surfaces irrespective of cutting parameters, while abrasive ploughing and scratches were mainly found on the processed surfaces of titanium plate. CFRP/Ti6Al4V stack configuration was preferred to generate overall superior surface roughness during AWJ slotting CFRP-titanium multilayer stack.