나노 실리카 복합재료의 기계적 성질에 관한 실험적 연구

Abstract

The tensile test was performed and chemical property was investigated with X-ray photoelectron spectroscopy(XPS). The friction and wear characteristics of the rubber matrix composites filled with nano sized silica particles were investigated at ambient temperature by pin-on-disc friction test. The range of volume fraction of silica particles tested are between 11% and 25%. The Charpy impact tests are conducted to evaluate the effect of volume fraction and temperature in the range between –40 ℃ and 0 ℃. The purity of nano silica composites was checked by XPS. The increase of volume fraction of silica leads to increase in the tensile strength. The cumulative wear volume shows a tendency to increase nonlinearly with increase of sliding distance. As increasing the silica particles of these composites indicated higher friction coefficient. The wear rate of these composites tested indicated low value as increasing the sliding distance. The major failure mechanisms were lapping layers, deformation of matrix, ploughing, debonding of particles and microcracking by scanning electric microscopy photograph of the wear tested surface. The critical energy release rate of the rubber matrix composites filled with nano sized silica particles is affected by silica volume fraction and it is shown that the value of decreases as volume fraction increases. The critical energy release rate of the rubber matrix composites filled was considerably affected by temperature and it was shown that the maximum value was appeared at higher temperature for temperature test and it was shown that the value of increases as temperature increases. The major fracture mechanisms were matrix deformation, silica particle debonding and delamination, microcrack between particles and matrix and/or pulling out between particles and matrix which is ascertained by SEM photographs of Charpy impact surfaces fracture.