不同处理方法对碳纤维表面形态及Cf/C复合材料强度的影响

采用浓硝酸和电化学两种不同的表面处理技术,对碳纤维表面处理,利用SEM对纤维表面进行了分析,并对其所制备的Cf/C复合材料抗弯性能进行了测试.结果表明:采用低电压,短时间处理,对碳纤维表面作用较温和,粗糙度和比表面积增加,对复合材料的增强效果较浓硝酸氧化处理的显著.经10V,10min处理后,纤维表面出现"松树皮"状凸起,复合材料力学性能下降.电化学处理碳纤维以提高复合材料界面性能的机理至少包括薄弱外层的去除和对纤维表面的刻蚀两种作用,在混合作用中,对纤维表面刻蚀作用占据主导地位.

Effect of Carbon Fiber Surface and Strength of Cf/C Composite by Different Treatment Methods

Dense nitric acid and electrolytic surface treatment techniques were adopted,the shapes of surface after treatment were analyzed by SEM,and flexural strength of C_f/C composite prepared with treated fibers was tested.The results showed that surface of carbon fibers was treated softly under condition of low voltage and short time,and with increases of roughness specific surface areas,the intensity of composite reinforced more effective than that of dense nitric acid treatment.After 10 voltage and 10 minutes treatment,"pine cortex" heaves appeared on the surface of carbon fiber,and the composite intensity decreased markedly.The mechanism of electrolytic treatment improving interface properties of the composite includes at least two effects with weaker outer layer remove and surface etching,and etching effect is dominant in this simultaneous process.