In-situ cutting temperature and machining force measurements during conventional drilling of carbon fiber polymer composite laminates

Abstract

The evolution of in-situ cutting temperature and machining forces during conventional drilling of multi-directional carbon fiber reinforced polymer (MD-CFRP) laminates using a novel inverted drilling setup is presented. The in-situ cutting temperature was measured using fiber Bragg grating (FBG) optical sensor embedded in the stationary drill. The effect of machining parameters such as spindle speed and feed rate on the temperatures and machining forces were studied that indicate the predominant effect of spindle speed on machining temperatures. The drilled MD-CFRP samples and drill bits were characterized by scanning electron microscopy (SEM) and micro-computed tomography ([Formula: see text]) techniques to assess machining-induced damage in the samples and tool wear in the drill bits. Exit-ply delamination was observed in MD-CFRP samples that aggravates with increase in cutting temperature and thrust force caused by evolving tool wear. The measured in-situ machining temperatures using the current experimental setup can be used to achieve better machining models.