摘要
利用激光驱动飞片方法模拟研究高速碎片对聚四氟乙烯(PTFE)薄膜材料的撞击,并利用扫描电镜(SEM)观测材料中心断裂区域与沿径向断裂区域的断裂特征,结果表明,中心区域的断裂面主要为韧性断裂,而沿径向的断裂为脆性断裂。飞片速度越高,材料的主撞击坑尺寸越大,断裂面呈粗糙分布,而速度较小时,主撞击坑断裂面相对平滑;材料厚度达到100μm时,几乎抑制了材料沿径向的撕裂。利用高速撞击时材料形成的温度梯度理论和断裂源的形成机制以及聚合物的玻璃化转变温度理论解释了材料在不同应变率下的断裂机制。
Laser driven flyer method was applied to simulate the hypervelocity impact on polytetrafluoroethylene （PTFE） film with different thickness.The characteristics of hypervelocity impact at different velocity was studied by means of scanning electron microscope （SEM）.100 μm thick PTFE film exhibits no radial crack under 2.9 km/s impact.As for 50 μm PTFE,it is found that the central penetration region exhibits ductile fracture,while the radial cracking region exhibits brittle fracture.With an increase in flyer velocity,the damage morphology in the central penetration region of PTFE experiences a rough-to-smoothness transition.The temperature gradient related to glass transition temperature of polymer and the mechanism of polymer fracture was applied to interpret this novel behavior.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2010年第11期44-47,共4页
Polymer Materials Science & Engineering
基金
中国博士后科学基金面上资助项目(63378)
