Study Of Fabrication Technology And Properties Of GF-Pb Composites

Lead is attractive for its yawp controlling capacity. Based on the studying of fabrication technology for glass fiber reinforced lead matrix (GF-Pb) composite filament, GF-Pb composite net and board with high damping capacity were successfully fabricated by netting and rolling. The microstructure of the composites was examined by optical microscope and SEM. The molding capability of the composites was studied. The mechanical properties were tested by tensile test, and then fracture face pattern was analyzed. The damping capacity was evaluated by dynamic mechanical analysis (DMA).The results indicated that the best molding temperature is about 20℃, because the crystal size of the composites increases with the temperature increasing. And the state of interface between different lead layers is good enough at 20℃. As rolling thickness decreased, the density of composites increased first then reduced. The turning point for D1 is about 1.2 mm. The molding range is 1.2 mm>d>0.8 mm. The turning point for D2 is about 1.0 mm, and the molding range is 1.0 mm>d>0.7 mm.In the process of netting and rolling, the intensity of composites reduced. Compare with the filament, the strength of composite net decrease. The main reasons are intensity losing in netting and intensity losing for net structure. And the intensity losing in netting is about 40 MPa. Compare with net, the board intensity decreased. The main reason is glass fiber yarn is composed of many thin glass fibers and is brittle material. So the glass fiber was damaged in rolling process. Compare with matrix, the composite board is a little stronger. So this method has limitation for brittle fiber reinforced composites, but the damping capacity of composites fabricated by this means enhanced notablely.The damping capacity of GF-Pb composites is higher about 20 times than pure lead. The interface between glass fiber and matrix is a main damping source in composites. The investigation of the damping-strain curve showed that the damping capacity showed strain amplitude dependent and independent regions.The curves were well interpreted by interface micro-slippage mechanism. The damping raising speed of board is superior to net. Because the glass fiber in board has been destroyed, the interface micro-slippage occurs more easily and thoroughly. The investigation of the damping-temperature-frequency curve showed that the damping capacity increased when the temperature increased or the frequency decreased.The damping mechanism of composites is: interface friction damping mechanism, plastic deforming damping mechanism and material damping.