1,730,295 research outputs found
Production of Aluminium 6061 samples obtained via FDM, debinding and sintering processes
No full textopenNel presente elaborato si andranno ad effettuare stampa FDM, debinding (chimico e termico) ed infine la sinterizzazione su alcuni provini di Alluminio 6061 con l'obiettivo di ottenere una completa rimozione del polimero e un elevato grado di densità finale del campione stesso.In this work, FDM printing, debinding (chemical and thermal) and finally sintering will be carried out on some 6061 Aluminum specimens with the aim of obtaining complete removal of the polymer and a high degree of final density of the sample itself
Creation with FDM technique, debinding and sintering and analysis of Aluminum 6061 samples
No full textopenL’obiettivo principale della ricerca presentata nel seguente elaborato è quello di definire i parametri operativi caratterizzanti le varie fasi di realizzazione di componenti in lega di alluminio 6061 attraverso il metodo di stampa 3D fused deposition modelling (FDM).
Sono stati condotti esperimenti riguardanti le fasi di stampa, di debinding (termico e chimico) e di sinterizzazione utilizzando pezzi di filamento e campioni con geometria cilindrica e cubica
[[alternative]]The Study of Weld Hot Cracking of Aluminum Alloys 6061 and 7075
No full text[[abstract]]Abstract
The main purpose of this study was focusing on the heat treatable 6061 and 7075 aluminum alloys to make use of inert Gas Tungsten Arc Welding (GTAW), in the condition of using spot Varestraint test method with no filler metal to evaluate the weld hot cracking susceptibility under different augmented strain and weld frequency. Then, explored the relationship between mechanical properties, microstructure and the weld hot cracking susceptibility of two aluminum alloys by microhardness test, optical microscope and scanner electron microscope.
The conclusion of this study showed that, in the spot Varestraint test, the increase of frequency with the augmented strain and thermal cycle, the total crack lengths have displayed the trend of increase to both 6061 and 7075 aluminum alloys. In 6061 aluminum alloy material, 6061-T6(H) has the best resistance to hot cracking susceptibility, 6061-O is next, 6061-T6 is the last. In 7075 aluminum alloy material, 7075-T6(H) has the better resisting hot cracking susceptibility than 7075-T6.According as the increase of augmented strain, the total crack lengths of both 6061 and 7075 aluminum alloys have displayed the trend of increase in fusion zone and heat affected zone. As for the same augmented strain, according as the increase of thermal cycle frequency, the hot cracking of both 6061 and 7075 aluminum alloys in the fusion zone have not been affected by multi thermal cycle, and the total crack lengths have displayed the trend of increase in heat affected zone. Moreover, the total crack length in the weld metal heat affected zone is longer than the base metal heat affected zone. The figures of metallographic microstructure have showed the hot cracking of 6061 and 7075 aluminum alloys occurred in the fusion zone and heat affected zone. In the mean while, the obvious crack occurred along the crystalline grain boundary, and the liquation cracking length is more less than the solidification cracking length. Furthermore, the microstructure figure of the scanner electron microscope showed, the cracking fracture surface of 6061 and 7075 aluminum alloys have displayed the type of the spot welding fusion zone to solidification cracking and the heat affected zone to liquation cracking.
[[alternative]]A Study of Torch Brazing for Wrough Aluminum Alloy Plates of 1100 and 6061(T6)
No full text[[abstract]]In order to explore the best brazing parameter, torch brazing is used to braze the wrough aluminum alloy plates of 1 100 and 6061(T6) by using filler metals of BAlSi-4 and TA1OO in the type of lap joint. The joint shear strength was compared through the tensile test. Further more, the change of microstructure was examined by optical microscope and micro hardness test.
The result showed that there is no different between the joint shear strength using the filler metals BAlSi-4 and TA1OO for 1100 aluminum alloy. For the wrough 6061 (T6) aluminum alloy plates, the joint shear strength of brazing filler metal TA 100 is higher than filler metal BAlSi-4.
There are reduction in the strength and hardness of base metal for bath 1100 or 6061 (T6) wrough aluminum alloy plates. Because the wrough 1100 aluminum alloy plate is strengthened by cold working, brazing heat caused recrystallization and increase in grain size. The decrease of mechanical properies of wrough 6061 (T6) aluminum alloy plate was obtained by heat treatment during brazing.
In addition, there is diffusion of Silicon in the weidment of wrough 1100 aluminum alloy plates and promote the increase of hardness of base metal. But no diffusion was observed in 6061 (T6) aluminum alloy.
Extrusion Textures in Al, 6061 Alloy and 6061/SiCp Nanocomposites
Full text linkThe 6061 alloy matrix composites reinforced with 10wt% and 15wt% of SiC nanoparticles with an average diameter of ~500nm were hot extruded in strip shape from ball milled powders. The microstructures and textures of the hot extruded nanocomposites have been investigated by means of three dimensional orientation distribution functions and electron backscatter diffraction (EBSD) techniques. Pure Al and 6061 alloy extruded strips from atomised powders have been produced for comparison purposes. The results show that the non-deformable SiC particulates have a strong influence on the formation of extrusion textures in the matrix. Pure Al and 6061 alloy develop a typical β fibre texture after extrusion in strip shape. For 6061/SiCp nanocomposites, the intensities of major texture components decrease with increasing amount of SiC particles. The total intensities of Brass, Dillamore and S components have decreased by 19% for 6061/10wt%SiCp and 40% for 6061/15wt%SiCp composites when compared with the 6061 alloy. EBSD analysis on local grain orientations shows limited Al grain rotations in SiC rich zones, resulting in the decreased texture intensities.Fil: Jiang, X.. University of Oxford; Reino UnidoFil: Galano, Marina Lorena. University of Oxford; Reino Unido. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Audebert, Fernando Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina. University of Oxford; Reino Unido. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Mecánica. Grupo de Materiales Avanzados; Argentin
การศึกษาปัจจัยที่มีผลต่อการตัดเฉือนในงานกัดอะลูมิเนียมผสมเกรด 6061-T6
Full text link งานวิจัยนี้มีวัตถุประสงค์เพื่อศึกษาปัจจัยที่มีผลต่อการตัดเฉือนและสร้างสมการถดถอยทำนายค่าความหยาบผิวในงานกัดอะลูมิเนียมผสมเกรด 6061-T6 โดยนำเทคนิคการออกแบบเซ็นทรัลคอมโพสิตแบบเฟสเซ็นเตอร์ และกำหนดระดับปัจจัยใช้วิธีการปีนขึ้นด้วยเส้นทางที่ชันที่สุด ผลการศึกษาพบว่า ระยะป้อนลึกและอัตราป้อนมีผลต่อความหยาบผิวของชิ้นงานอย่างมีนัยสำคัญ และปัจจัยที่เหมาะสมให้ค่าความหยาบผิวต่ำสุด คือ อัตราป้อน 35.60 มิลลิเมตรต่อนาที และระยะป้อนลึก 1.875 มิลลิเมตร ได้สมการถดถอยใช้ทำนายค่าความหยาบผิว ค่าความหยาบผิว = 0.0279616+0.0244447(ระยะป้อนลึก)-4.76401x10-4(อัตราป้อน)+8.22542x10-6 (อัตราป้อน2) เมื่อทดสอบสมมติฐานเปรียบเทียบค่าเฉลี่ยความหยาบผิวที่ได้จากการทดลองเพื่อยืนยันสมการกับค่าที่ได้จากการแทนค่าสมการถดถอย พบว่าค่าทั้งสองไม่แตกต่างกัน ดังนั้นสมการถดถอยใช้ทำนายค่าความหยาบผิวของอะลูมิเนียมผสมเกรด 6061-T6 ได้
คำสำคัญ: ระยะป้อนลึก อัตราป้อน ความหยาบผิว อะลูมิเนียมผสมเกรด 6061-T6 การทดลองแบบเซ็นทรัลคอมโพสิต
This research aims to study factors affecting surface roughness and determine the regression model to prodict surface roughness in CNC precision milling process of 6061-T6 aluminum alloy using a technique of central composite design face-centered. The study employed steepest ascent technique to identify levels of factors. The experimental results indicated that the significant factors were main effect of depth of cut and feed rate. The regression model was established and used to determine the minimum surface roughness with feed rate of 35.60 millimeter per minute and depth of cut of 1.875 millimeter. The regression model used to predict the surface roughness is expressed as Ra = 0.0279616+0.0244447(Depth of cut)-4.76401x10-4(Feed rate)+8.22542x10-6(Feed rate2). After experiment verification, the significance and validity of the models were confirmed. Therefore, it could be concluded that established regression model was the reliable tool to predict the surface roughness of 6061-T6 aluminum alloy.
Keywords: Depth of cut, Feed rate, Surface roughness, 6061-T6 Aluminum alloy, Central composite desig
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Precipitation hardening 6061 Aluminum weldments
No full textIncludes bibliographical references (page 41)6061 aluminum is a precipitation hardenable alloy that is used\ud
extensively in structural applications. Large ring shaped parts fabricated from\ud
6061 are often rolled from annealed flat stock. A welding operation is required\ud
to join the ends of the part after shaping. The part is then precipitation\ud
hardened to bring the 6061 alloy up to the T6 condition. Unfortunately, the\ud
weld metals commonly used to join 6061 do not achieve the same hardness\ud
as the parent metal in the T6 condition.\ud
In this study the effects of weld rod type, welding procedure, and\ud
postweld heat treatments were examined. Four different weld rods were used\ud
to join 6061 samples. The welding was done with and without a water chi lied\ud
fixture attached to the specimens being welded. Welded specimens were aged using ten different heat treatment cycles that included 9900F or 9700F\ud
solution treatments and natural or artificial aging at 3200F or 3500F.\ud
The 6061 parent material relies on a Magnesium Silicide precipitate for\ud
hardening effects. Three of the weld rods used, (X4643, 5356, & 5556), have\ud
similar AI-Mg-Si alloy constituents. The fourth rod, 4043, is a AI-Si alloy.\ud
The X4643 weld rod was the only weld alloy to match the T6 condition\ud
of the 6061 parent metal after aging. This occurred only in the water chilled\ud
case where the chill minimizes melting of the parent material during the\ud
welding process and increases the solidification rate of the weld metal. The\ud
appearant effect of the chill is to promote a finer dendritic structure
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