BN/PTFE喷口复合材料力学性能及失效机理研究

Study on mechanical performance and failure mechanism of BN/PTFE nozzle composites

系统研究了不同含量氮化硼(BN)填充聚四氟乙烯(PTFE)复合材料的拉伸强度及断面微观形貌,分析了冷压–烧结工艺成型过程中BN/PTFE复合材料各组分的变化规律,提出了该类材料断裂失效机理,指出添加BN会使PTFE材料出现结合不良的微观界面,破坏PTFE材料结构完整性,影响应力在复合材料内的有效传导,从而导致力学性能下降,且随BN含量的增加,BN对基体结构完整性的破坏程度会愈发明显。

The tensile strength and cross section morphology of the polytetrafluoroethylene(PTFE)composites filled with different content of boron nitride(BN)were systematically investigated.The variation rules of various components in the BN/PTFE composites during the cold pressing-sintering process molding were analyzed.The fracture failure mechanisms of these materials were proposed.It is pointed out that the addition of BN will cause the poor bonding micro-interface of PTFE materials,destroy the structural integrity of the PTFE materials,affect the effective conduction of stress in the composites,thus lead to the decrease of mechanical performance.With increasing of BN content,the destroy degree of BN to the matrix structural integrity will be more obvious.