Analyses of forces and hole quality in micro-drilling of carbon fabric laminate composites

Aerospace, automobile and medical industries extensively use carbon fabric laminate due to their superior physical and chemical characteristics and, from performance point of view, micro-features are provided on certain components. In this work, an attempt has been made to drill micro-holes in carbon fabric laminate composites using 320 μm diameter carbide drills. Based on a preliminary study, drilling strategy with peck cycle is chosen for through-hole drilling in carbon fabric laminate. Micro-drilling experiments are conducted according to full-factorial design using five levels for both speed and feed with three trials for each condition. Thrust force and torque generated during machining are measured and power law based regression models are developed. Though the material is anisotropic and non-homogeneous in nature, the models developed follow the trend in the experimental results. Delamination damage, roundness error and diameter of these drilled holes are measured and analyzed with variation of the process parameters. The results indicate that the good quality micro-holes can be produced by selecting proper process parameters. © 2012 The Author(s).