Guan Siman, Wang Zhijun, Tang Xuezhi, Hao Ruijie, Yi Jianya
School of Mechatronic Engineering, North University of China, Taiyuan 030051, China.
Chongqing Hongyu Precision Industry Group Co., Ltd., Chongqing 402760, China.
Polymers (Basel). 2025 May 17;17(10):1380. doi: 10.3390/polym17101380.
In order to study the microstructure evolution of polytetrafluoroethylene-copper (PTFE-Cu) composites under compression load and reveal the molecular dynamics mechanism of deformation failure, three PTFE-Cu composites with different densities (3.0 g/cm, 3.5 g/cm, 4.0 g/cm) were prepared in this study. The crystallinity of PTFE in each sample was determined via differential scanning calorimetry (DSC). The quasi-static compression mechanical properties test was carried out to analyze the effect of PTFE crystallinity on the macroscopic mechanical response of the composites. It is found that the crystallinity of the three PTFE-Cu composites was 43.05%, 39.49% and 40.13%, respectively, showing a non-monotonic trend of decreasing first and then increasing with an increase in copper powder content. The elastic modulus and yield strength of the material are negatively correlated with the crystallinity. The failure mode is the axial splitting failure and the composite morphology of axial splitting failure and shear tearing. Finally, the molecular dynamics simulation method is used to reveal the microstructure evolution and deformation failure mechanism of PTFE-Cu composites under compression load from the atomic scale, which provides a theoretical basis and experimental support for understanding the mechanical properties of PTFE-Cu composites.
为了研究聚四氟乙烯-铜（PTFE-Cu）复合材料在压缩载荷下的微观结构演变并揭示其变形破坏的分子动力学机制，本研究制备了三种不同密度（3.0 g/cm³、3.5 g/cm³、4.0 g/cm³）的PTFE-Cu复合材料。通过差示扫描量热法（DSC）测定各样品中PTFE的结晶度。进行了准静态压缩力学性能试验，以分析PTFE结晶度对复合材料宏观力学响应的影响。结果发现，三种PTFE-Cu复合材料的结晶度分别为43.05%、39.49%和40.13%，呈现出随铜粉含量增加先降低后升高的非单调趋势。材料的弹性模量和屈服强度与结晶度呈负相关。破坏模式为轴向劈裂破坏以及轴向劈裂破坏与剪切撕裂的复合形态。最后，采用分子动力学模拟方法从原子尺度揭示了PTFE-Cu复合材料在压缩载荷下的微观结构演变和变形破坏机制，为理解PTFE-Cu复合材料的力学性能提供了理论依据和实验支持。
