Mazur Karolina, Gądek-Moszczak Aneta, Liber-Kneć Aneta, Kuciel Stanisław
Faculty of Materials Engineering and Physics, Institute of Materials Engineering, Tadeusz Kosciuszko Cracow University of Technology, al. Jana Pawła II 37, 31-864 Cracow, Poland.
Faculty of Mechanical Engineering, Institute of Applied Informatics, Tadeusz Kosciuszko Cracow University of Technology, al. Jana Pawła II 37, 31-864 Cracow, Poland.
Materials (Basel). 2021 Mar 31;14(7):1712. doi: 10.3390/ma14071712.
The key goal of this study was to characterize polytetrafluoroethylene (PTFE) based composites with the addition of bronze particles and mineral fibers/particles. The addition of individual fillers was as follows: bronze-30-60 wt.%, glass fibers-15-25 wt.%, coke flakes-25 wt.% and graphite particles-5 wt.%. Both static and dynamic tests were performed and the obtained results were compared with the microscopic structure of the obtained fractures. The research showed that the addition of 60 wt.% bronze and other mineral fillers improved the values obtained in the static compression test and in the case of composites with 25 wt.% glass fibers the increase was about 60%. Fatigue tests have been performed for the compression-compression load up to 100,000 cycles. All tested composites show a significant increase in the modulus as compared to the values obtained in the static compression test. The highest increase in the modulus in the dynamic test was obtained for composites with 25 wt.% of glass fibers (increase by 85%) and 25 wt.% of coke flakes (increase by 77%), while the lowest result was obtained for the lowest content of bronze particles (decrease by 8%). Dynamic tests have shown that composites with "semi-spherical" particles are characterized by the longest service life and a slower fatigue crack propagation rate than in the case of the long glass fibers. In addition, studies have shown that particles with smaller sizes and more spherical shape have a higher ability to dissipate mechanical energy, which allows their use in friction nodes. On the other hand, composites with glass fiber and graphite particles can be successfully used in applications requiring high stiffness with low amplitude vibrations.
本研究的关键目标是对添加青铜颗粒和矿物纤维/颗粒的聚四氟乙烯（PTFE）基复合材料进行表征。各填料的添加量如下：青铜-30-60重量%，玻璃纤维-15-25重量%，焦炭薄片-25重量%，石墨颗粒-5重量%。进行了静态和动态测试，并将所得结果与所获断裂面的微观结构进行了比较。研究表明，添加60重量%的青铜和其他矿物填料提高了静态压缩试验中获得的值，对于含有25重量%玻璃纤维的复合材料，其增幅约为60%。对压缩-压缩载荷进行了高达100,000次循环的疲劳试验。与静态压缩试验中获得的值相比，所有测试的复合材料的模量均有显著增加。动态试验中，模量增幅最高的是含有25重量%玻璃纤维（增幅85%）和25重量%焦炭薄片（增幅77%）的复合材料，而青铜颗粒含量最低的复合材料增幅最低（降幅8%）。动态试验表明，含有“半球形”颗粒的复合材料具有最长的使用寿命，且疲劳裂纹扩展速率比长玻璃纤维的情况要慢。此外，研究表明，尺寸较小且形状更接近球形的颗粒具有更高的机械能耗散能力，这使其可用于摩擦节点。另一方面，含有玻璃纤维和石墨颗粒的复合材料可成功用于要求高刚度且低振幅振动的应用中。
