Low-frequency vibration-assisted drilling of hybrid CFRP/Ti6Al4V stacked material

The drilling of carbon fiber-reinforced polymers (CFRP) and Ti6Al4V alloy stacked materials play a significant role in the aerospace industry's ability to achieve improved machinability and assembly. Conventional drilling has resulted in various challenges such as CFRP delamination, unacceptable hole accuracy, and high tool wear. In addition, high cutting temperatures and poor chip evacuation mechanisms were also identified as important difficulties necessitating the drilling of each material separately. Low-frequency vibration-assisted drilling (LF-VAD) promises a high potential for overcoming these challenges. The primary objective of this study was to investigate the effect of machining parameters (cutting speed, feed rate, modulation amplitude, and modulation frequency) on the LF-VAD stacked drilling of CFRP/Ti6Al4V. The effect of applying a 2.5-cycle/rev frequency modulation to a wide range of machining parameters is reported, and the results are discussed. The variables considered included cutting speed, feed rate, and modulation amplitude. The results show up to a 56% reduction in cutting temperature, as well as a change in chip morphology. The effects on hole quality and surface roughness are also presented.