摘要
纳米尺度多层复合结构的动态冲击响应对半导体制造和微小粒子防护等具有重要意义。采用分子动力学方法模拟Si基底支撑的Ag-PMMA复合薄膜的抗冲击性能,通过对接触力响应、动能损耗、应力波传播、位错和损伤演化、侵彻深度等进行综合分析,解释了在衬底支撑条件下金属聚合物复合薄膜的能量耗散机制。结果表明,侵彻过程可以分为局部压缩阶段和整体变形阶段。在局部压缩阶段,Ag表面接触区域原子在高速冲击下由于应力集中效应直接转化为无定形结构,因而接触力达到侵彻过程的峰值。薄膜厚度主要在整体变形阶段产生影响:较薄的复合薄膜明显受到衬底的限制,在高速冲击下直接发生贯穿性损伤;而较厚的复合薄膜通过Ag的集体位错和PMMA的弹性变形耗散子弹动能,能够充分发挥各层材料特性。
It is very important for semiconductor manufacturing and small particle protection to study the dynamic impact response of nano-scale multi-layer composite structures.Molecular dynamics simulation was used to investigate the impact resistance of Ag-PMMA composite films supported with Si substrates in this paper.The energy dissipation mechanism of the metal polymer composite film supported on the substrate was explored through contact force response,kinetic energy loss,stress wave propagation,dislocation and damage evolution,and penetration depth.The results show that the impact process includes local compression stage and global deformation stage.During the local compression stage,the atoms in the contact region of Ag surface directly transform into amorphous structures due to the stress concentration effect under high-speed impact,so the contact force reaches the peak of the whole penetration process.The thickness of the film mainly affects the global deformation stage.The thinner composite film is obviously limited by the action of the substrate,and the penetrating damage occurs directly under the high-speed impact.However,the thicker composite film dissipates the kinetic energy of the bullet through a large number of Ag dislocations and PMMA elastic deformation,which can give full play to the material performance of each layer.
作者
林高建
高文鹏
陈鹏万
孙伟福
LIN Gaojian;GAO Wenpeng;CHEN Pengwan;SUN Weifu(State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology,Beijing 100081,China)
出处
《高压物理学报》
CAS
CSCD
北大核心
2023年第4期134-146,共13页
Chinese Journal of High Pressure Physics
基金
国家自然科学基金(12111530281)。
