Research On The Machinability Of Aramid Fiber Reinforced Plastics

AFRP(Aramid Fiber Reinforced Plastics)is widely used in the aerospace, military and automotive area for its' excellent material performance, such as low density, high specific tensile strength and modulus, good impact resistance, high strength, but which, for the same reason, causes difficulty during machining. The secondary processing, such as drilling, contouring and slotting, is needed before assembly. But it's easy for machining AFRP to lead to delamination, burning, fibre pull-out, uncut fibres, high surface roughness and lack of dimensional stability. Some of these problems are associated with the typical laminated structure of material, others are due to the distinct properties of the fibre and matrix. In addition, machining AFRP also causes serious problem with tool wear.The main content of this article are as follows:(1)The processing quality of AFRP is researched. An experiment is conducted to study machining defects occured on the surface after processing. Reasons that cause these defects are discussed. Then the relationship between cutting parameters, such as spindle speed, feed per tooth and cutting depth, and machined surface quality is analyzed. Rotating the table to change the helical angle of cutting tool, the workpiece is machined with different tool helical angle. The results indicate that the machined surface quality has been improved with the increasing of tool helix angle, and the cutting parameters have almost no effect on it.(2)The cutting force of AFRP is researched. As an important aspect of machinability, cutting force is also a key research object. Cutting force signals are acquired during machining. Influence of cutting parameters and tool helical angle on cutting force is analyzed. It is found that improving tool helical angle can decrease cutting force. And the differences of cutting force in a rotation when cutting different tool helical angle are discussed.(3)An experiment is conducted by cutting AFRP with a backup plate. Choosing aluminium alloy as backup plate material, the machined surface quality has been improve a lot. The changed trend of machined surface quality and cutting force, which is caused by the change of cutting parameters and tool helical angle, has been discussed. Two types of cutting tool are used in cutting experiment to study the relationship between the tool material and tool wear, cutting force, machined surface quality, et at.