Yazar "Cakir, O." seçeneğine göre listele
Listeleniyor 1 - 4 / 4
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Chemical etching of aluminium(Elsevier Science Sa, 2008) Cakir, O.Chemical etching is employed as micromachining manufacturing process to produce micron-size components. The process applies a strong chemical etchant solution to remove unwanted part in the workpiece material. It is basically a corrosion-controlled process. Chemical etching process has a long history and accepted one of the important nontraditional machining processes during the last half century. The method is widely applied to machine geometrically complex parts from thin and flat of any material. it is also used to reduce weight of the workpiece materials. In this study, aluminium was machined by well-known chemical etchant, ferric chloride (FeCl3) at different etching temperature. The effects of selected chemical etching parameters on depth of etch and surface finish quality were investigated. It was observed that FeCl3 was very useful chemical etching for aluminium etching. (c) 2007 Elsevier B.V. All rights reserved.Öğe Examination of machining parameters on surface roughness in EDM of tool steel(Elsevier Science Sa, 2007) Kiyak, M.; Cakir, O.Electrical discharge machining (EDM) is one of the important non-traditional machining processes and it is widely accepted as a standard machining process in the manufacture of forming tools to produce molds and dies. Since its introduction to manufacturing industry in late 1940s, EDM became a well-known machining method. The method is based on removing material from a workpiece by means of a series of repeated electrical discharges, produced by electric pulse generators at short intervals, between an electrode (tool) and a part being machined in dielectric fluid medium. This paper is devoted to a study of the influences of EDNI parameters on surface roughness for machining of 40CrMnNiMo864 tool steel (AISI P20) which is widely used in the production of plastic mold and die. The selected EDM parameters were pulsed current (8, 16 and 24 A), pulse time (2, 3, 4, 6, 12, 24, 48 and 100 mu s) and pulse pause time (2 and 3 ps). It was observed that surface roughness of workpiece and electrode were influenced by pulsed current and pulse time, higher values of these parameters increased surface roughness. Lower current, lower pulse time and relatively higher pulse pause time produced a better surface finish. (C) 2007 Elsevier B.V. All rights reserved.Öğe Peripheral vascular injuries due to firearms in children(W B Saunders Co Ltd, 2006) Goz, M.; Cakir, O.; Eren, N.Background. Vascular injuries caused by firearms are rare among children. In this paper we discuss the surgical methods of treating peripheral vascular injuries due to firearms in children. Materials and methods. Forty-four patients with peripheral vascular injuries due to firearms were included in this retrospective study. The patients were under the age of 14 and treated in our clinic between January 1985 and December 2004. Results. Vascular injuries due to firearms in children made up 4.9% of all cases of vascular trauma in our clinic. The male to female ratio was 38:6, and the age range was 3-14. The survival rate was 98% and the rate of limb salvage was 91%. For arterial and venous injuries, a saphenous vein interposition graft and interrupted sutures were often preferred surgically. Conclusion. Peripheral vascular injuries due to firearms in children and other accompanying traumas can be easily identified and treated, and have low morbidity and mortality with an acceptable limb salvage rate if a rapid and effective approach is used.Öğe Surface integrity of finished turned Ti-6Al-4V alloy with PCD tools using conventional and high pressure coolant supplies(Elsevier Sci Ltd, 2007) Ezugwu, Emmanuel O.; Bonney, John; Da Silva, Rosemar B.; Cakir, O.Surfaces generated when machining Ti-6Al-4V alloy with PCD tools using conventional and high pressure coolant supplies was investigated. Longer tool life was recorded when machining Ti-6Al-4V with high-pressure coolant supplies and the recorded surface roughness R-a values were well below the tool rejection criterion (1.6 mu m) for all cutting conditions investigated. The micro-structure of the machined surfaces were examined on a scanning electron microscope. Micrographs of the machined surfaces show that micro-pits and re-deposited work material were the main damages to the surfaces. Micro-hardness analysis showed hardening of the top machined surfaces when machining with conventional coolant while softening of the subsurface layer was observed when machining under high-pressure coolant supplies. The later is probably due to lower heat generated, with the consequent tempering action when machining with PCD tools with high-pressure coolant supplies. The microstructure below the machined surfaces had minimal or no plastic deformation when machining with conventional and high-pressure coolant supplies. (C) 2006 Elsevier Ltd. All rights reserved.
