چكيده به لاتين
In producing new products, the strength-to-weight ratio of parts is of significant importance. In order to increase this ratio, part manufacturers use new materials called composites, one of the most important of which is carbon-epoxy. This material is utilized to manufacture bodies for aircraft, vehicles, bicycles, wheelchairs, and sports goods. Drilling is commonly used in addition to adhesives to join carbon-epoxy to other components. This process suffers from delamination and ovality, which depend on the input parameters. Controlling these parameters can enhance the quality output of the drilling process. In this research, the qualitative features of a compression-molded carbon-epoxy plate in the drilling process are evaluated, and the process input parameters for reaching the best quality are selected. The most important output parameters of the drilling process are the delamination factor, ovality, and the axial force exerted on the plate, which is affected by input parameters, such as cutting speed, feed rate, and tool type. Tests were designed with the full factorial method, in which The cutting speed was selected in the range of 37.7-150.8 m/min, and the feed rate was chosen within a range of 10-100 mm/min.
Moreover, twist drill bit, Brad Spur drill bit, and end mil tools with diameters of 8mm were used. The delamination and ovality of holes were measured with a VMM device, and the axial force was measured using a dynamometer. Also, the chips’ shapes were evaluated, and one test of each tool was selected as the best output for that tool. In the twist drill bit, a spindle speed of 75.4 m/min and a feed rate of 10 mm/min; in the Brad Spur drill bit, a spindle speed of 150.8 m/min and a feed rate of 70 mm/min, and the end mill tool, a spindle speed of 113.1 m/min and a feed rate of 70 mm/min were chosen as the best drilling conditions. Finally, the three best holes' inner surface was compared with SEM images. The twist drill bit was the best choice regarding minimum axial force and roughness, and the end mill tool was the best selection regarding hole quality and drilling speed.
