Hole quality evaluation of natural fiber composite using image analysis technique

The natural fiber-reinforced composites are emerging as a possible replacement to glass fiber composite for low-cost applications. Of the various machining process, drilling is one of the most common machining processes used for the assemblage of various parts. During drilling process, composites undergo delamination phenomenon that reduces the structural reliability of the component. The present work focuses on the analysis of delamination behaviour as a function of drilling process parameters at the entrance and exit of the composite plates. In this work, drilling was carried out by varying the feed (0.1, 0.2, 0.3 mm/rev) and speed (500, 1000, 1500 and 2000 r/min), respectively. The drill bit used is made of high-speed steel of a diameter of 10 mm. The quality of the hole drilled was assessed using the machine vision technique, and the extent of delamination was carried out using the ultrasonic C-scan imaging method. The experimentally observed delamination factor was compared with ANOVA technique and found that the feed rate affect the delamination than speed. A correlation between the parameters of interest was carried out using multi-variable linear regression analysis technique.