摘要
用扫描电镜(SEM)研究了聚碳酸酯/双峰聚乙烯(PC/BMPE)合金断裂面的形貌,其断裂面可以分为裂纹引发区和裂纹扩展区.裂纹扩展区形成了大量的纤维,且这些纤维具有很大的塑性形变,而裂纹引发区几乎没有纤维形成,这是裂纹在缺陷处引发时存在气穴现象的缘故.冲击作用所产生的应力导致了裂纹尖端微空穴和聚合物纤维连结的形成,这个过程包括表面牵拉和纤维拉伸,裂纹形成时存在纤维的微颈细化过程,并用微颈细化理论建立了其微颈细化的理论模型.
The morphology of fracture surface of polycarbonate/bimodal polyethylene I PC/BMPE） alloy was studied by scanning electron microscopy （ SEM ）. The fracture surface can be divided into two regions ： crack initiation region and crack propagation region. A large number of fibrils was formed in the crack propagation region, and the fibrils display large plastic deformations. But there is scarcely any fibril in the crack initiation region due to cavitation at defects which initiated cracks. Schematic formation of a craze as an interconnected structure of microvoids and polymer fibrils upon application of stress stem from impact force was presented. This process involve surface - drawing and fibril traction. It has been shown that crazing of the alloy is a micronecking process. The model of micronecking was established through the necking theories.
出处
《湘潭大学自然科学学报》
CAS
CSCD
北大核心
2007年第3期84-87,共4页
Natural Science Journal of Xiangtan University
关键词
聚碳酸酯
双峰聚乙烯
裂纹
扩展
polycarbonate
bimedal polyethylene
crack
evolution
