Surface formation and kerf characteristics during single-pass abrasive waterjet slotting of hybrid CFRP/metallic stacks

Abrasive waterjet is proposed as a promising technique for high-efficient cutting of hybrid composite-metal structures. This study comprehensively studied the effects of machining strategies (including different traverse speed, hydraulic pressure and stack configuration) on material removal mechanisms, kerf characteristics and surface integrity during abrasive waterjet slotting of thick CFRP/aluminum stacks. Power-to-speed ratio (E(over dot)/u) was firstly employed as a significant parameter to understand the relationship between machining parameters and kerf width/surface roughness variation. Experimental results demonstrated that kerf geometry was sensitive to processing parameters, and kerf profile was closely related to the stacking configuration. The kerf width increased significantly with higher E(over dot)/u level before reaching the threshold value. A rapid decrease of surface roughness was observed at relatively lower E(over dot)/u value. "V" and "X" shaped kerf profiles were formed on CFRP/Al and Al/CFRP stacks respectively, and the corresponding formation mechanisms of specific kerf profile were further investigated. (c) 2022 CIRP.