Hydrothermal aging effects on mechanical properties of hybrid composites

In the current study, hydrothermal aging effect on mechanical properties of glass/aramid/epoxy hybrid composites investigated experimentally. Composite specimens immersed in distilled water and sea water at 25°C and 70°C temperatures for 1000 hours. This study can be divided into two parts. In the first part of study, the distilled/sea water gain of hybrid/non-hybrid composites were weighted periodically and calculated analytically according to Fick's law. In the second part of the study, mechanical tests (tensile, flexural and impact tests) were conducted to the samples exposed to aging. The test specimens were catagorized into three groups as dry, wet and re-dried. At the end of study, the fracture types of specimens were imagened. The results showed that fluid type, temperature and sequences of composite fabrics were direct affect in meaning of water gain of composites. Aramid/epoxy laminates absorbed more water than glass/epoxy laminates. Moreover, the hybrid composites absorbed more water if aramid fabrics were located at outer surface. The mechanical test results revealed that distilled/sea water were caused the change of mechanical properties of hybrid/non-hybrid composites. It was observed that water type, temperature, order of fabrics, conditions of testing of samples (dry, wet, re-dried) had an effect on mechanical properties of hybrid/non-hybrid composites.