A study on tool wear of tungsten carbide cutters in edge trimming of CFRP

Carbon fiber reinforced polymer (CFRP) composites are widely used in the aerospace field because of their outstanding lightweight material characteristics, tensile strength, and stiffness properties. The tools used in composite machining exhibits different cutting performance and machining quality under different cutting conditions. The combination of tool material, tool geometry, and cutting conditions strongly influence the tool life and surface quality of the machined parts. Edge trimming of CFRP blanks with tungsten carbide two flute end mill cutter was conducted. The operation was carried out on a computer numerical control (CNC) router by varying cutting speed, feed speed, and depth of cut. Experimental results indicated that the wear of carbide tools is characterized by abrasive wear and rounding of the cutting edge. This occurred mainly by hard abrasion of the carbide grains. Tool life was observed to be inversely proportional to cutting speed, feed speed, and depth of cut. An expanded tool wear equation with power, average temperature, and resultant force as independent variables provided higher tool wear predictive capabilities. To check the adequacy of the regression model, validation runs were conducted. The experimental tool wear obtained from validation experiments were compared with the tool wear obtained using regression. An approximate average error of 5 % confirms that the experimental and regression tool wear values are very close. The equations and analysis permit trimming of CFRP to be designed such that tool wear is optimized and well forecasted.