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Öğe EVALUATION OF NON-ASBESTOS HIGH PERFORMANCE BRAKE PADS PRODUCED WITH ORGANIC DUSTS(Tanger Ltd, 2015) Öktem, Hasan; Uygur, İlyas; Akıncıoğlu, Gülşah; Kır, Durmuş; Karakaş, HamdiRecently, research-development studies conducted for the production of organic brake pads because of the usage of asbestos in brake pads have negative effects on human health and the environment. This study aims to develop to non-asbestos high performance brake pads. Twenty-four types of different dusts in commercial brake pads have utilized as fillers, reinforcements, binders, abrasives and friction modifiers in mixture of organic brake pads produced. In this study, seventeen of these friction dusts were used to develop to organic brake pads. The 3.5 wt.% and 7 wt.% content of hazelnut and walnut as friction modifier materials were replaced with petrocoke dust eco-friendly. The performance of brake pads was determined by microstructural examinations, oil absorption and dimensional stability, and hardness of brake pads. The results indicated that the brake pads produced with organic dusts such as hazelnut and walnut shells can replaced with petrocoke dust. From this, it can be concluded that new type brake pads of non-asbestos organic-based dusts can be effectively used as a replacement for asbestos and performance in brake pad production.Öğe COMPARISON OF MANUFACTURING TECHNIQUES SUBJECT TO HIGH SPEED IMPACT(Amer Soc Mechanical Engineers, 2015) Gollins, Kenneth; Chiu, Jack; Delale, Feridun; Liaw, Benjamin; Gürsel, AliIn this paper we compare two manufacturing techniques namely vacuum infusion and compression molding, used in manufacturing S2 glass fabric/epoxy composites for high-speed impact applications. Even though compression molding and vacuum infusion are two widely used manufacturing techniques, the resulting product may be very, different. Compression molding has the advantage of achieving a much higher fiber density for the same thickness. With a higher fiber density, the composites made by compression molding have better mechanical properties than a composite made by vacuum infusion. However, vacuum infusion is faster and more. economical. The mechanical performance of the composites manufactured by these two processes are compared by performing tensile tests and high speed impact tests for the' determination of the limit speed V-50. For the same number of plies, preliminary results for compression molded specimens indiCate a 50% increase in stiffness and a 40% increase in strength. Also, for panels of the same thickness, the V-50 was higher for compression molding specimens.Öğe Experimental investigation of the effects of infrared heating mechanism on the mechanical properties of autoclave cured CFRPs(Applied Mechanics Laboratory, 2019) Alpay, Yakup; Uygur, İlyas; Öz, Fatih E.Autoclave curing method is widely used in manufacturing of aerospace and automotive grade carbon fiber reinforced plastic (CFRP) components. However, both the autoclave operating costs and long curing times yield high component costs and limit the mass production ability. These limitations make researchers to canalize their efforts to cost effective solutions without sacrificing the product quality. These cost effective solutions can be classified into two main groups: reducing the curing times and enhancing the efficiency of the process. In this study, effects of heating mechanism on the curing and mechanical properties of autoclave cured CFRPs were investigated. Infrared and conventional resistance heating were considered and compared. For this purpose, an infrared curing oven was constructed to simulate the autoclave cure cycle without pressure. Infrared heating is a cost effective mechanism than conventional resistance heating because it just heats the material instead of whole autoclave chamber. 75 mm x 250 mm x 3 mm CFRP plates were fabricated in this infrared oven. They were cut into 3 pieces for tensile testing. Results were compared with the ones manufactured by conventional autoclave oven at the same cure cycle. A correlation of the results of the mechanical properties and curing behaviors of the products was obtained. Results showed that infrared can be used for curing of CFRPs instead of resistance heating, especially in plain geometries. But for complex shapes, a homogen heating pattern should be provided by adjusting the location of infrared heaters with regard to the product geometry. In the light of these findings, it can be deduced that hybrid autoclave ovens can be developed which are using both infrared heating and resistance heating so as to enhance the efficiency of the process in composite plate manufacturing. © CCM 2020 - 18th European Conference on Composite Materials. All rights reserved.Öğe Diffusion bonding of iron and bronze by mirowave sintering(European Powder Metallurgy Association (EPMA), 2007) Kurt, Adem; Ateş, Hakan; Uygur, İlyas; Gürhan, A.H.In this study, diffusion bonding of Fe and Bronze (90%Cu+10% Sn) powders used as bearing materials has been investigated by microwave sintering. For this purpose Fe and Bronze powders were compacted at 250, 350 and 500 MPa and sintered via microwave energy and conventional sintering process. Green and sintered densities were measured. Fe- Bronze interfaces and porosity changes were investigated after microwave and conventional sintering.
