Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Joining and Interfacial Properties of Aluminum/Glass Fiber Reinforced Polypropylene Sandwich Composites(Izmir Institute of Technology, 2009) Guruşçu, Aslı; Tanoğlu, MetinThe joining of separate components using a suitable technique is a critical step in the manufacture of composite structures. For good property performance of aluminum/glass fiber reinforced polypropylene (Al/GFPP) laminates, one of the most important problems is to obtain good adhesive bond strength.In the present study, Al/GFPP laminates have been manufactured with various surface pretreatment techniques. Adhesion at the composite/metal interface has been achieved by surface pretreatment of Al with amino based silane coupling agent, incorporation of polyolefin based adhesive film and modification with PP based film containing 20 wt. % a maleic anhydride modified polypropylene (PP-g-MA). The mechanical properties shear, peel and bending strength of the adhesively bonded Al/GFPP laminates were investigated to evaluate the effects of those various surface treatments. In addition, peel strengths of Al foam/GFPP laminates with various surface treatments were measured. The fracture surfaces have been examined by scanning electron microscope (SEM). Results showed that the adhesion of the laminated Al/GFPP systems were improved by treatment of aluminum surfaces with amino-based silane coupling agent. Based on peel and bending strength results, Al/GFPP laminates with incorporation of polyolefin based adhesive films exhibited significant increase on the adhesive behaviour. Modification of Al/GFPP interfaces with PP-g-MA layer leads to highest improvement on the adhesion properties.Master Thesis Effects of Processing Parameters on the Mechanical Behavior of Continuous Glass Fiber/Polypropylene Composites(Izmir Institute of Technology, 2009) Merter, Nevres Emrah; Tanoğlu, MetinFiber reinforced polymeric composite materials have an increasing demand in industrial applications. Easy and rapid processing capability, high impact and delamination resistance, low moisture absorption and infinite shelf life of the raw materials are the attractive properties of continuous fiber reinforced thermoplastic composite materials. Therefore, thermoplastic based composites find in many application areas in automobile, aerospace, construction, defense, transportation and marine industries. In recent years, hybrid fabrics; composed of continuous glass fibers and polymer fibers such as polypropylene (PP), have been used to fabricate thermoplastic composite with higher fiber volume fraction and improved performance. In this study, hybrid fabrics were developed by commingling the continuous PP and glass fibers using air jet and direct twist hybrid yarn preparation techniques. The hybrid commingled fabrics obtained with 450 fiber orientation and non-crimp fabric pattern. Non-crimp fabrics were obtained various fiber sizing that are compatible and incompatible with PP matrix to investigate the effect of interfacial adhesion on the properties of the thermoplastic composites. Composite panels were produced from these fabrics via hot press compression method. Microstructural properties of the composites were investigated by matrix burn-out test and optical and scanning electron microscopy (SEM) analyzes. Tensile, compression, flexural and interlaminar peel tests were used to investigate the mechanical properties of the composites. Impact properties of the composites were examined by charpy impact test. Results showed that laminates of the fabrics fabricated by air jet hybrid yarn preparation technique exhibit superior properties to those fabricated by direct twist covering hybrid yarn preparation technique. The results also showed that the fabrics with polypropylene compatible sizing results with enhanced composite properties.