Delamination Characterization and Comparative Assessment of Delamination Control Techniques in Abrasive Water Jet Drilling of CFRP

Composite laminates are used in many applications in industries like aerospace and aircraft due to their extremely high strength to weight ratio and corrosion resistance properties. The composite laminates are difficult to machine materials, which results into low drilling efficiency and drilling-induced delamination, thus it is important to develop an innovative advanced drilling process to overcome the difficulties related in the machining of composite materials. This work is focused on comprehensive experimental characterization to understand the effect of cutting parameters on the delamination extent during abrasive water jet drilling of carbon fiber reinforced polymer. Processing parameters, such as standoff distance and water pressure plays dominant role in delamination than abrasive flow rate. It also describes the development of different techniques for controlling the delamination in abrasive water jet drilling process, such as backup plate, pre-drilled hole and water immersion (under water). The analysis shows that abrasive water jet drilling with backup plate yields lower delamination, hole size variation and hole surface roughness.