1,723,396 research outputs found
Deformation induced phase transformation during machining of Ti-5553
No full textTi-5553 is a relatively new titanium alloy with applications particularly in the aerospace industry for such key structural components as landing gear. However, during machining of Ti-5553, the elevated temperature and high strain at tool-workpiece interface may alter workpiece microstructure and result in ß to a phase transformation. During phase transformation, some intermediated phase such as w phase may form which is brittle and hard to machine, and it could reduce the fatigue life of machined components. The aim of this research work is to optimize the machining condition for Ti-5553, in which its hot deformation behavior in terms of ß to a phase transformation could be fully understood. Analysis of variables such as micrographs of phase components and cutting zone temperature demonstrates that the cutting temperature governs the formation of final phase components and to some extent this variation has been quantified to allow for further and more detailed investigation
Deformation induced phase transformation during machining of Ti-5553
No full textTi-5553 is a relatively new titanium alloy with applications particularly in the aerospace industry for such key structural components as landing gear. However, during machining of Ti-5553, the elevated temperature and high strain at tool-workpiece interface may alter workpiece microstructure and result in β to a phase transformation. During phase transformation, some intermediated phase such as ω phase may form which is brittle and hard to machine, and it could reduce the fatigue life of machined components. The aim of this research work is to optimize the machining condition for Ti-5553, in which its hot deformation behavior in terms of α to a phase transformation could be fully understood. Analysis of variables such as micrographs of phase components and cutting zone temperature demonstrates that the cutting temperature governs the formation of final phase components and to some extent this variation has been quantified to allow for further and more detailed investigation
Shear displacement and actual strain during chip segmentation when cutting aerospace alloy Ti-5553
No full textTi-5553 (Ti-5Al-5Mo-5V-3Cr-0.5Fe) is a recently developed near-β Ti alloy with potential application in structural components of aircrafts. However, Ti-5553 has shown poorer machinability than other Ti alloys. The objectives of the present study are to understand the chip formation mechanism, calculate the actual strain within the segments of chip and its narrow shear bands, and to evaluate the effect of cutting condition on the shear strain. Cutting tests were conducted under three levels of cutting speeds and feeds, and the chips micrographs were collected and analyzed. It was found that the cutting conditions have a significant impact on the shear strain
Integrating phase field and crystal plasticity finite element models for simulations of titanium alloy Ti-5553
No full textAbstract
The ability to simultaneously predict the microstructure and bulk material properties of 3D printed (additively manufactured or AM) metals is critical to the development of process intelligence that can be used by a digital-twin for forecasting and optimising alloy composition and fabrication parameters. This study proposes a simulation framework for predicting the microstructure and corresponding meso- and macro-scale properties of AM materials. This is achieved by integrating phase-field and crystal plasticity modelling techniques, whereby the phase field model predicts the microstructure and the crystal plasticity constitutive model computes the stress–strain evolution using the microstructure as the input. The simulation of multiple microstructures demonstrates that this integrated approach can be used to test the influence of different microstructures on the mechanical properties of titanium alloy Ti-5553. This includes the influence of grain size and grain orientation on both the meso- and macro-scale behaviour
Integrating phase field and crystal plasticity finite element models for simulations of titanium alloy Ti-5553
No full textThe ability to simultaneously predict the microstructure and bulk material properties of 3D printed (additively manufactured or AM) metals is critical to the development of process intelligence that can be used by a digital-twin for forecasting and optimising alloy composition and fabrication parameters. This study proposes a simulation framework for predicting the microstructure and corresponding meso- and macro-scale properties of AM materials. This is achieved by integrating phase-field and crystal plasticity modelling techniques, whereby the phase field model predicts the microstructure and the crystal plasticity constitutive model computes the stress-strain evolution using the microstructure as the input. The simulation of multiple microstructures demonstrates that this integrated approach can be used to test the influence of different microstructures on the mechanical properties of titanium alloy Ti-5553. This includes the influence of grain size and grain orientation on both the meso- and macro-scale behaviour
An Experimental Investigation of Hot Machining with Induction to Improve Ti-5553 Machinability
Get PDFThe manufacturing of aeronautic parts with high mechanical properties requires the use of high performance materials. That’s why; new materials are used for landing gears such as the titanium alloy Ti-5553. The machining of this material leads to high cutting forces and temperatures, and poor machinability which requires the use of low cutting conditions.
In order to increase the productivity rate, one solution could be to raise the workpiece initial temperature. Assisted hot machining consists in heating the workpiece material before the material removal takes place, in order to weaken the material mechanical properties, and thus reducing at least the cutting forces.
First, a bibliography review has been done in order to determine all heating instruments used and the thermal alleviation that exists on conventional materials.
An induction assisted hot machining was chosen and a system capable to maintain a constant temperature into the workpiece during machining (turning) was designed.
Trails permit to identify the variation of cutting forces according to the initial temperature of the workpiece, with fixed cutting conditions according to the TMP (Tool-Material-Pair) methodology at ambient temperature. Tool life and deterioration mode are identified notably.
The results analysis shows a low reduction of specific cutting forces for a temperature area compatible with industrial process. The reduction is more important at elevated temperature. However, it has consequences on quality of the workpiece surface and tool wear
Zuchthäuslerin Nr. 5553
No full textZUCHTHÄUSLERIN NR. 5553
Zuchthäuslerin Nr. 5553 ( - )
Cover ( - )
Imprint ([2])
[Abb.]: Frau Ly van Brackel ( - )
Title page ([3])
Inhalt ([5])
I Der Wolf in der Schafsherde - Wieso und warum ich in Paris blieb - Der polizeiliche Hammel ([7])
II Das siegestrunkene Paris - Bittere Reflexionen - Fatum - Eine teure Flasche Rüdesheimer - Die Sans-chaussures - Frankreichs Schande - Ein tapferes Dämchen - Das Medical-Hotel (14)
[Abb.]: Wohnungs-Ausweis der Elsässerinnen Kreutzer in Paris (Uebersetzung im Text) ( - )
[Abb.]: Regiments-Abzeichen der "Queen Marys Own", von Frau von Brackel als Erkennungszeichen für die englischen Soldaten getragen ( - )
III Madame Messimy - Der Flieger - Das feige Ministerium - Ich werde Chefarzt - Frankreichs Fürsorge für die Verbündeten - Ein Militärtransport - Mein Afrikaner (22)
[Abb.]: Frau Dr. Booth im Kreise ihrer englischen Pfleglinge ( - )
[Abb.]: Ein englischer Freundschaftsbeweis (Uebersetzung im Text) ( - )
IV Man spricht Deutsch - Die Vlamen - Ein Spitzbubenstreich - Ich stehle eine Flasche Kognak und sehe Papillon - Es gelingt (33)
V Ich steige in Würde und mir steigt was in die Nase - Der mißhandelte Landsmann - Ein neuer Transport - Es wird brenzlich - Fata Morgana - In der Falle - Maitrefeu, der Menschenfreund - Zum erstenmal im Gefängnis (38)
VI Ein furchtbares Erwachen - Das Depot - Mammy - Auch das Gefangensein will gelernt werden - Der "Gardin Chef" - Die Trennung (45)
[Abb.]: "Zuchthäuslerin Nr. 5553" ( - )
[Abb.]: Ein Zeugnis zur Behandlung deutscher Schwestern im Gefängnis von St. Lazare-Paris ( - )
VII St. Lazare - Wir armen Mütter - Hungerlehrling - Ein moralischer Coctail - Das Gift - Die Anklage (52)
VIII Geschmuggelte Briefe - Eine Spazierfahrt - Mother - Zurück nach St. Lazare - Die Diakonissinnen und der Zoo - Erwischt - Wir pfeifen was drauf (59)
IX Die Verhandlung - Vor dem dritten Kriesgericht - Il n'y a meilleurs remède contre la mélancolie q' un jugement, tant sont les juges ordinairement d'une bêtise réjouissante. (Es gibt kein besseres Mittel gegen die Melancholie als einen Richterspruch, von so aufheiternder Dummheit sind die Richter gewöhnlich.) V. Hugo. (68)
X Wieder ein Abschied - Im Atelier - Hoffnungsfreude - Eine unwürdige Komödie - Frei?? (73)
XI Nr. 5553 - Zwischen Mörderinnen - Der Fluchtversuch - Die Strafzelle - Ich werde geschlagen (80)
XII Wieder Mensch - Der Dritte im Bunde - Ich resigniere - Meine Zerstreuungen - Hammer und Amboß - Neuer Fluchtgedanke - Das Militärgefängnis - Huissier. (91)
XIII Heraus aus dem Gefängnis - Wenn einer eine Reise tut - In Paris - Cuisery. (101)
XIV Das Lager - Ich fürchte mich - ein Wiedersehen - L'espionne - Es geht wieder los - Wie Amerika mich zu einer Mondscheinpromenade zwingt. (106)
XV Meine Selbstmordgedanken - Eine zweite Mondscheinpromenade - 12 Kilometer in stockdunkler Nacht - Wieder ein Flieger - Die Amerikaner - Im Maul des Löwen - Er schnappt nicht zu. (115)
XVI Autofahrt durch Paris - Besuch bei Kreutzer (129)
XVII Die große Neuigkeit - Die Heimkehr der verlorenen Tochter - Von neuem hinter den Gittern - Dreist und gottesfürchtig - Zum letzten Mal in Gefahr (131)
XVIII So grüß' ich dich, mein Heimatland. (138)
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Cryogenic Machining of Titanium Ti-5553 Alloy
No full textTitanium alloy Ti-5Al-5V-3Cr-0.5Fe (Ti-5553) is a new generation of near-beta titanium alloy that is commonly used in the aerospace industry. Machining is one of the manufacturing methods to produce parts that are made of this near-beta alloy. This study presents the machining performance of new generation near-beta alloys, namely, Ti-5553, by focusing on a high-speed cutting process under cryogenic cooling conditions and dry machining. The machining experiments were conducted under a wide range of cutting speeds, including high speeds that used liquid nitrogen (LN2) and carbon dioxide (CO2) as cryogenic coolants. The experimental data on the cutting temperature, tool wear, force components, chip breakability, dimensional accuracy, and surface integrity characteristics are presented and were analyzed to evaluate the machining process of this alloy and resulting surface characteristics. This study shows that cryogenic machining improved the machining performance of the Ti-5553 alloy by substantially reducing the tool wear, cutting temperature, and dimensional deviation of the machined parts. The cryogenic machining also produced shorter chips as compared to dry machining
Microstructure and Properties of Ti-5553 Alloy for Aerospace Fasteners
No full textThe effect of heat treatment on microstructure and mechanical properties of Ti-5553 alloy was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that when the alloy is treated in α+β phase zone, tensile strength decreases with raising solution temperature due to decreasing the content of primary α-phase and increasing the size and volume fraction of β phase. A lot of secondary α-phase precipitates from grain boundary and intragranular with β phase transformation during aging treatment. The size of secondary α-phase has significant influence on tensile strength, secondary α-phase coarsens gradually with the increase of aging temperature, resulting in the decrease of tensile strength. It is suggested that for 1240MPa aerospace fasteners the solution temperature of Ti-5553 should be under Tβ, thus adequate β phase, where a lot of secondary α phase precipitates from, is good for the required high strength. Meanwhile, a certain percentage of primary α-phase is kept for acquiring good ductility and toughness. After solution treatment at 810-820℃ for 1.5h, water quenching plus aging at 510℃ for 10h, Ti-5553 shows a better mechanical property with tensile strength 1500MPa, elongation 14.8% and reduction of cross-section area 38.6%. Lots of dimples can be found in tensile fracture after solution treatment and solution+aging treatment, which demonstrate Ti-5553 with good ductility and toughness
Tİ-5553 alaşım malzemesinin talaşlı imalat sürecinde kesici takım aşınmalarının yüzey bütünlüğüne etkisinin incelenmesi
No full textTi-5553 Alaşım Malzemesinin Talaşlı İmalat Sürecinde Kesici Takım Aşınmalarının Yüzey Bütünlüğüne Etkisinin İncelenmesi Titanyum alaşımları, özellikle havacılık endüstrisinde bıçaklar, gaz türbin motorları, kompresör ve disk gibi yapısal bileşenler için mükemmel mukavemet-ağırlık oranı, güçlü korozyon direnci ve mukavemeti yüksek sıcaklıklarda muhafaza etme yetenekleri sayesinde yaygın olarak kullanılan malzemelerdir. Yeni nesil beta titanyum alaşımı Ti-5553 (Ti-5Al-5V-5Mo-3Cr), yüksek mukavemet, kırılma tokluğu, yüksek korozyon ve yorulma direnci gibi bazı üstün özelliklere sahiptir. Bu üstün özellikler, uçaklarda gelişmiş bileşenler için Ti-5553'ü daha cazip hale getiriyor. Ancak bu özellikler aynı zamanda Ti-5553 alaşım malzemesinin işlenebilirliği Ti-64'e (Ti-6Al-4V) kıyasla azaltıyor, yüksek takım aşınmasına ve çok kısa takım ömrüne neden olur. Bu çalışmada, işlenmiş Ti-5553'ün takım aşınmasına bağlı yüzey bütünlüğü, yüzey pürüzlülüğü, mikroyapı, topografya, XRD ve mikro sertlik değişimleri açısından araştırılmış. Takım serbest yüzey aşınmasının etkisini incelemek için takım ömrü deneyleri ve tek paso işleme işlemleri gerçekleştirilmiştir. Bu çalışmada 18 mm çapında Ti-5553 kullanılmıştır. İşleme parametreleri olarak, tek paso deneylerinde, kesme hızları Vc = 30, 90, 120, 150 ve 210 m / dk olarak seçilmiştir ve takım ömrü deneyleri için kesme hızı Vc 90 ve 120 m / dk olarak seçilmiştir. Tüm işleme süreçlerinin ilerleme sabit olarak alınmıştır, f = 0.15mm / dev. Bu çalışmanın deneysel kısmı kuru, MQL, Kriyojenik, HPC ve kesme sıvısı ve CO2 gibi farklı kesme koşullarında eğik kesme operasyonunu içermektedir. Talaşlı imalat işlemleri Doosan Puma GT2100 CNC işleme merkezinde yürütülmüştür. Yüzey pürüzlülük değerleri Mitutoyo SJ-210 ile ölçülür. Vc = 120 m / dak'da işlenmiş Ti-5553 mikroyapıları, Philips XL 30 SFEG taramalı elektron mikroskobu (SEM) ile incelenmiş ve Vc = 90 m / dak'da işelenen numunelerin mikro yapılarını incelemek için Olympus BX51M optik mikroskop kullanılmıştır. İşlenmiş numunelerin faz dönüşümünü incelemek için, X-ışını Difraksiyonları Analizi için Bruker AXS Marka D2 Phaser kullanılır. Tüm mikro sertlik olasılıklarını ölçmek için Vickers mikro test cihazı kullanıldı. Eğik kesme testlerinde, seçilen kesme parametrelerinde işlenen parçaların aritmetik ortalama yüzey pürüzlülükleri genellikle 1 μm’nin altında kalmıştır. Bu değerden sapmalar ise genellikle işlenen yüzeydeki topografik kusurlar sonucudur . Dolayısı ile Ti-5553 alaşımları yüksek kesme hızlarında işlenildiginde yüzey pürüzlülüğünde önemli bir artış söz konusu olmadığı bu çalışma ile görülmüştür. İlaveten aşınmanın 600 μm’ye kadar ulaşmasıda yüzey pürüzlülüğünde önemli artışa sebep olmamaktadır. Ancak artan aşınma miktarının işlenen parçanın topografisinde önemli bozulmalara neden olduğu da görülmektedir ki bu durum artan aşınma sonucunda beklenilen bir durumdur. Yüzey kalitesi ve topografik açıdan değerlendirildiğinde diğer tüm koşullara nazaran yüksek basınçlı soğutma sıvısının kullanımının Ti-5553 alaşımın işlenmesinde önemli katkı sağladığı söylenebilir. Özellikle kesme sıvısı ve kuru kesmede düşük aşınma miktarlarında bozulan topografi, yüksek basınçlı soğutmada aşınmanın artmış olduğu durumda dahi topografi halen kararlılığını korumaktadır.Investigation of the effects of Tool Wear on Surface Integrity of Ti-5553 Alloy in Machining Process Titanium alloys are commonly used materials especially in aerospace industry for structural components such as blades, gas turbine engines, compressor and disk thanks to their excellent strength-to-weight ratio, strong corrosion resistance and ability to retain high strength at high temperatures. A new generation near beta titanium alloy Ti-5553 (Ti-5Al-5V-5Mo-3Cr) has some superior properties such as high strength, fracture toughness, high corrosion and fatigue resistance. This superior properties makes Ti- 5553 more attractive for advanced component in aircrafts. But this properties also leads poor machinability and high tool wear and so short tool life when compared to Ti-64 (Ti-6Al-4V). In this study, tool wear induced surface integrities of machined Ti-5553 have been investigated in terms of surface roughness, microstructure, topography, XRD, and micro hardness changes while tool flank wear of the uncoated carbide insert is increasing in turning operation. To examine effect of tool flank wear, tool life experiments and single pass machining operations were carried out. In this study, 20 mm diameter Ti-5553 was used. As machining parameters, cutting speeds, Vc were chosen as 30, 90, 120,150 and 210 m/ min for machining of Ti-5553 in single pass machining and Vc were chosen as 90 and 120 m/ min for tool life experiments. Feed rates of all machining processes is taken as constant, f=0.15mm/ rev. Experimental part of this study includes oblique cutting under different cutting conditions dry, MQL, Cryogenic, HPC, and Flood and CO2. Turning experiments are conducted Doosan Puma GT2100 CNC turning center. Surface roughness values are measured with Mitutoyo SJ-210. Microstructures of machined Ti-5553 at Vc=120 m/ min were examined with Philips XL 30 SFEG scanning electron microscopy (SEM) and Olympus BX51M optical microscopy is employed to examine micro structures of ti 5553 at vc =90 m/ min and ti-64 at vc=120m/ min. to examine phase transformation of machined specimens, Bruker AXS Marka D2 Phaser is employed for X-ray Diffractions Analysis. To measure all micro hardness chances, Vickers micro test was used. At oblique cutting processes and in the selected cutting parameters, the arithmetic mean surface roughness of the machined parts is generally less than 1 μm. Deviations from this value are usually the result of topographical defects on the treated surface. Therefore, when Ti-5553 alloys were processed at high cutting speeds, there was no significant increase in surface roughness. In addition, it does not cause a significant increase in surface roughness when wear reaches up to 600 μm. However, it can be seen that the increased amount of wear causes significant deterioration in the topography of the treated part, which is expected in the case of increased wear. Considering the surface quality and topography, it can be said that the use of high pressure coolant compared to all other conditions makes a significant contribution to the machining of Ti-5553 alloy. The topography is still stable in the case of the application of the high pressure cooling
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