Effect of Cutting Method on Mechanical Properties of Polymer Matrix Composite Open-Hole Sample

The rectangular sample with diameter of 6 mm hole in the center and with size of 200 mm×25 mm×2 mm was prepared on the glass fiber reinforced phenolic resin matrix composite, carbon fiber reinforced epoxy resin matrix composite and glass fiber reinforced epoxy resin matrix composite plate by tool machining, abrasive water jet processing and nanosecond laser processing. The machining accuracy, surface roughness and topography under different cutting methods were compared. The effect of cutting methods on mechanical properties of different composites was studied. The results show that the sample surface roughness was the smallest under abrasive water jet processing, followed by tool machining, both with high processing accuracy. The sample surface roughness was the largest under nanosecond laser processing, with low processing accuracy. There were a few burrs and delamination defects on the side of the hole under tool machining and abrasive water jet processing, and no cracking and heat-affected zone existed on the cutting surface. Serious ablation and oxidation occurred on the cutting surface under nanosecond laser processing. For glass fiber reinforced phenolic resin matrix composite, the open-hole tensile strength was similar under the three cutting methods. For carbon fiber reinforced epoxy resin matrix composite, the open-hole tensile strength under tool machining was the largest, followed by that under abrasive water jet processing, and that under nanosecond laser processing was the smallest. For glass fiber reinforced epoxy resin matrix composite, the open-hole tensile strength under tool machining and abrasive water jet processing was similar and large, while that under nanosecond laser processing was small.