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Öğe Friction Coefficient and Compression Behavior of Particle Reinforced Aluminium Matrix Composites(Eos Assoc, 2019) Ugur, A.; Gokkaya, H.; Sur, G.; Eltugral, N.Metal matrix composites (MMCs) are materials used in a large range of engineering applications. In this paper, the relatively low-cost stir casting is evaluated with the use for Silisyum Carbite (SiC) as reinforcement and Al7075 alloy as matrix to produce MMCs with varied reinforcement from 10% to 18%. The produced composites were examined, and their wear behavior was investigated. The results showed that the mechanical properties of the MMCs decrease with the increase of the mass percentage of reinforcement and compression.Öğe Friction Coefficient and Compression Behavior of Particle Reinforced Aluminium Matrix Composites(Dr D. Pylarinos, 2019) Ugur, A.; Gokkaya, H.; Sur, G.; Eltugral, N.Metal matrix composites (MMCs) are materials used in a large range of engineering applications. In this paper, the relatively low-cost stir casting is evaluated with the use for Silisyum Carbite (SiC) as reinforcement and Al7075 alloy as matrix to produce MMCs with varied reinforcement from 10% to 18%. The produced composites were examined, and their wear behavior was investigated. The results showed that the mechanical properties of the MMCs decrease with the increase of the mass percentage of reinforcement and compression. © 2019, Dr D. Pylarinos. All rights reserved.Öğe Functionally Graded Material Production and Characterization using the Vertical Separator Molding Technique and the Powder Metallurgy Method(Dr D. Pylarinos, 2022) Kayabasi, I.; Sur, G.; Gokkaya, H.; Sun, Y.Functionally Graded Materials (FGMs) are advanced customized engineering materials that gradually and continuously change their composition. The current study investigated the production feasibility and some post-production mechanical/physical properties of B4 C particle-reinforced (avg. 40µm) AA7075 matrix (avg. 60µm) FGM composites with the vertical separator molding technique using the high-temperature isostatic pressing powder metallurgy method. FGMs produced consist of three (0 – 30 – 60 wt. % B4 C) and four (0 – 20 – 40 – 60 wt. % B4 C) layers. The powders were mixed in a power blender mixer for 2h and were placed in the mold sections with a vertical separator. The lid was closed, and a pre-pressure of 10Mpa was applied. The FGM green sheet was transferred from the vertical separator mold to the hot work tool steel with a press. In this mold, FGMs were sintered at 560°C for 30 min under a pressure of 325MPa. Microstructural examinations did not reveal any separation or crack formation in the layer transition regions of the FGMs. In addition, a relatively homogeneous B4 C reinforcing distribution was observed in the layers with a low reinforcement ratio (wt. 20% and 30%) compared to the other layers. The highest hardness was 170 HBN in one layer of the four-layer FGM containing 40% by weight B4 C reinforcement. The highest transverse rupture strength was measured in the test performed from the region with the most reinforcement of the four-layer FGM at 482MPa. © 2022, Dr D. Pylarinos. All rights reserved.Öğe Functionally Graded Material Production and Characterization using the Vertical Separator Molding Technique and the Powder Metallurgy Method(Eos Assoc, 2022) Kayabasi, I.; Sur, G.; Gokkaya, H.; Sun, Y.Functionally Graded Materials (FGMs) are advanced customized engineering materials that gradually and continuously change their composition. The current study investigated the production feasibility and some post-production mechanical/physical properties of B4C particle-reinforced (avg. 40 mu m) AA7075 matrix (avg. 60 mu m) FGM composites with the vertical separator molding technique using the high-temperature isostatic pressing powder metallurgy method. FGMs produced consist of three (0 - 30 - 60 wt. % B4C) and four (0 - 20 - 40 - 60 wt. % B4C) layers. The powders were mixed in a power blender mixer for 2h and were placed in the mold sections with a vertical separator. The lid was closed, and a pre-pressure of 10Mpa was applied. The FGM green sheet was transferred from the vertical separator mold to the hot work tool steel with a press. In this mold, FGMs were sintered at 560 degrees C for 30 min under a pressure of 325MPa. Microstructural examinations did not reveal any separation or crack formation in the layer transition regions of the FGMs. In addition, a relatively homogeneous B4C reinforcing distribution was observed in the layers with a low reinforcement ratio (wt. 20% and 30%) compared to the other layers. The highest hardness was 170 HBN in one layer of the four-layer FGM containing 40% by weight B4C reinforcement. The highest transverse rupture strength was measured in the test performed from the region with the most reinforcement of the four-layer FGM at 482MPa.Öğe Optimization of Abrasive Water Jet Turning Parameters for Machining of Low Density Polyethylene Material Based on Experimental Design Method(Carl Hanser Verlag, 2014) Kartal, F.; Cetin, M. H.; Gokkaya, H.; Yerlikaya, Z.Studies to improve the machining of engineering materials have great importance for mechanical systems. Abrasive water-jet turning (AWJT) is a new and effective process for increasing machinability of engineering materials by providing temperature free cutting conditions, high surface quality and having no tool wear problem. In this study, AWJT of low density polyethylene (LDPE) material were investigated in terms of average surface roughness (ASR) and material removal rate (MRR) values and process parameters were optimized by experimental design method. The primary objectives of the study are to investigate AWJT process and system parameters to enhance machinability of LDPE material and to determine optimal processing parameters. Nozzle feed rate (5, 25 and 45 mm/min), abrasive flow rate (50, 200 and 350 g/min) and spindle speed (1000, 1500 and 2500 min(-1)) were analyzed as process parameters. Taguchi L-27 orthogonal full factorial design, optimization box and analysis of variance (Anova) were used for the experimentation and results analysis. Experimental results show that, AWJT process is more efficient in the machining of LPDE material than the conventional machining methods by increasing surface quality and MRR parameters. Minimum ASR and maximum MRR were obtained 1.67 mu m and 14072.02 mm(3)/min respectively; at optimum parameters of 5 mm/min nozzle feed rate, 350 g/min abrasive flow rate and 2500 min(-1) spindle speed.Öğe A strategic matrix for knowledge product development(International Business Information Management Association, IBIMA, 2012) Boca, G.D.; Gokkaya, H.The development of a new product by a company begins when the need to create a new product appears either due to be emergence of a new technology, or the appearance of a competitive product or a change in the existing legal framework and is completed with the final introduction of the product in the market. The paper present a matrix strategies and present also different evaluation of using FEM programs with different programs and the influence upon the life cycle of the product, especially from design stage of technological manufacturing. A company or an enterprise may proceed to a new product development whether that company or enterprise is part of a rapidly changing market or not. Those new products may be based already on another existing products based on new technology without the need of support from others. A company or enterprise decision to develop a new product is probably one of the most important decision to be made in the history of that company because a new product development is directly linked with the development and the evolution of that company. The types of companies to which design and development techniques are best applied are those which design and manufacture their own products, and in which competitiveness is described by factors such as: quality, price, functionality, development time, commercialization time.Öğe Tensile test specimen preparing three different cutting method influence on the AA 6061-T6(BHR Group Limited, 2014) Kartal, F.; Gokkaya, H.; Yerlikaya, Z.; Polat, R.Aluminum 6061 (T6) material which is widely used in aviation and defense industries was treated with tensile test in this study. The samples for tensile test were manufactured using three production methods (namely, milling, CO2laser and abrasive water jet (AWJ). Following the tests sample surfaces were assessed for their surface roughness values. Samples which meet the TS EN ISO 6892-1 standard were assessed for their tensile strength, yield strength, percentage elongation and constriction. Among the test samples, sample prepared by milling proved to provide the best surface roughness value (1.32 ?m). The highest tensile strength was obtained from the sample prepared using AWJ while the lowest was obtained from the sample prepared using laser cutting. Samples prepared using abrasive water jet showed 6.57 % difference in terms of tensile strength from samples prepared using milling. © BHR Group 2014 Water Jetting 22.Öğe Three-Point Bending Response of Corrugated Core Metallic Sandwich Panels Having Different Core Configurations – An Experimental Study(Dr D. Pylarinos, 2019) Zurnaci, E.; Nalbant, M.; Gokkaya, H.; Sur, G.Bending response of corrugated core metallic sandwich panels was studied experimentally under three-point bending loading. Two different core configurations were used: the corrugated monolithic core and the corrugated sliced core. The trapezoidal corrugated cores were manufactured from aluminum sheets via a sheet metal bending mould. After the sandwich panel samples were prepared, they were subjected to three-point bending tests. The load and displacement responses of the sandwich panels having different core configurations were obtained from the experimental testing. The influence of the core configuration on the three-point bending response and failure modes was then investigated. The experimental results revealed that the corrugated sliced core configuration exhibited an improved bending performance compared to the corrugated monolithic core configuration. © 2019, Dr D. Pylarinos. All rights reserved.Öğe Turning of (Cu-Cr-Zr) alloy with abrasive water jet(2012) Kartal, F.; Gokkaya, H.; Nalbant, M.In this research, the effect of the processing parameters on surface roughness during the turning of (Cu-Cr-Zr) alloy with abrasive water jet was studied. In the experimental studies, (Cu-Cr-Zr) alloy, ?30 and 240 mm in size, was processed with abrasive water. In the experiment, pump pressure was 350 MPa, in the form of garnet abrasive and 80 mesh in size and nozzle diameter were kept constant at 1.2 mm. In addition to that in the parameters of nozzle feed rates (10, 15, 20 and 25 mm/min), abrasive flow rates (50, 150, 250 and 350 gr/min) and nozzle distances (2, 5, 8, 11 mm) were used in the tests. According to the results of the experiment, the increase in nozzle feed rate and nozzle distance lead to increase in average surface roughness. On the other hand, the increase in the number of turning speed and abrasive flow rate lead to decrease in average surface roughness. Average surface roughness was measured between 2.5 and 5.5 ?m. © BHR Group 2012 Water Jetting 21.
