EFFECTS OF FIBER ORIENTATIONS AND TOOL GEOMETRY ON SUBSURFACE DAMAGE IN MACHINING OF UNIDIRECTIONAL COMPOSITE MATERIALS

摘要

Composites have found variety of applications in aerospace industries due to the fact that theycan be tailored to specific needs. Once the composite is manufactured it has to be machined tothe final dimensions of parts. Machining of composites is a complicated process as it is affectedby many parameters, the parameters being the machining conditions, material properties and thetool geometry. Changing the parameters on the machine can easily control the machiningconditions. However, material properties and the tool geometry are the ones, which playimportant roles in determining the subsurface damage in composites. This paper presents anattempt to investigate the effects of these parameters on the subsurface damage in obliquemachining of uni-directional carbon fiber reinforced composites. The experiments were carriedout on fiber orientations from 0 to 90 degrees. A combination of four different rake angles andthree different helix inclination angles is used for all the fiber orientations. The forces weremeasured and microscopic pictures of subsurface damage were compared. It was found from theresult that 60 and 80 degrees showed more subsurface damage.