Study On Grinding Characteristics Based On Anisotropy Of Carbon Fiber Composites

Carbon fiber composites have been widely used in aerospace and military fields due to their high specific modulus and high specific strength.With the increasing requirements for surface precision of the products in the above-mentioned fields and the increasingly complex structural shapes of the components,higher and higher requirements have been placed on the processing technology of carbon fiber composite materials.In this paper,the material removal mechanism of carbon fiber composites is analyzed.Based on the anisotropy of the materials,the carbon fiber composites are ground by diamond wheel,and the grinding force and grinding heat in the grinding process are measured in real time.The surface morphology and roughness of the machined surface were tested.The effects of grinding fiber angle and grinding parameters on grinding force,grinding heat and machining morphology and roughness were analyzed.The main research works are as follows:(1)The material removal mechanism of the material under different grinding fiber angles was obtained by single particle grinding test of carbon fiber composites.In the relationship between the grinding and processing of the fiber,the interfacial peeling is mainly used to form the groove marks formed by the longitudinal direction of the long fibers,and the defects form mainly composed of fiber voids,resin ploughs and intermittent fibers are formed;In the vertical fiber grinding relationship,the shear failure is mainly formed and the groove marks formed by the shear fractures are formed,and microcracks are generated in the groove marks under the pushing action of the abrasive grains;In the grinding processing relationship,it is mainly formed by the combination of shearing and extrusion,resulting in a relatively flat wear scar morphology;in the reverse fiber grinding relationship,there will be defects such as fiber pull-out or cracks under the action of the rake face mainly due to bending failure.(2)The carbon fiber composites were dry-grinded by diamond grinding wheel in the machining center,and the grinding force was measured in real time.The influence of grinding fiber angle and grinding parameters on the grinding force was studied.It is found that the deep-depth resistance is greater than the main cutting force during the whole grinding process;under the condition that the grinding parameters remain unchanged,the relationship between the grinding force under different grinding fiber angles is 135°>45°>90°> 0°;as the grinding depth increases,the main grinding force and the depth of cut resistance increase,and as the grinding depth increases,the degree of anisotropy of each carbon fiber composite material increases.As the spindle speed increases,the grinding force gradually decreases,and the grinding force is less affected by the speed at 0° of the four grinding fiber angles.(3)The grinding temperature was measured while grinding,and the grinding heat in the carbon fiber composite grinding process was lower than that of the metal processing,and it shows obvious anisotropy as the angle of the grinding fiber changes.As the spindle speed increases,the grinding temperature increases gradually;as the grinding depth increases,the temperatures under the four grinding fiber angles gradually increase.(4)The surface morphology after grinding was observed and the roughness was tested.The effects of different grinding fiber angles and grinding parameters on the surface morphology and surface roughness of the grinding were analyzed.It is found that different grinding fiber angles produce different surface topography and processing defects;as the grinding depth increases,the surface quality gradually decreases,and the number of processing defects increases;as the spindle speed increases,the surface quality improves.It is least affected by the velocity at 0° of the four grinding fiber angles.