Download or read book Fundamental Study of Hot Tearing Mechanisms of Aluminium silicon Alloys written by Joseph Langlais and published by . This book was released on 2006 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A theoretical model was updated from previous work using more realistic metallurgical quantities. This research led also to the development of a probalistic model (cellular automata) to simulate the microstructure of the cast sample. The model has been used to determine a crack propagation coefficient (CPC) that was used in the theoretical model to better represent the hot tear propagation." --

Download or read book Hot Tearing and Constitutive Behaviour of Semi solid Aluminum Alloys written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The occurrence of hot tearing during solidification is one of the major factors influencing both the quality and productivity of aluminum castings. In order to reduce the formation of hot tears, quantitative information regarding both hot tearing formation and semi-solid deformation is essential. In this study, the mechanisms of hot tearing and semi-solid deformation have been investigated via two novel techniques: x-ray micro-tomography on material deformed in the semi-solid region, and development of a three phase microstructural model based on a geometry derived from a Voronoi diagram with rounded corners and porosity. Numerical techniques were utilized to quantify both the size evolution and orientation of internal damage relative to void growth. In order to conduct the above research, a new semi-solid tensile deformation methodology was devised which uses a two thermocouple control technique to enable accurate measurement of semi-solid tensile strength and ductility. The experimental work was conducted on the aluminum - magnesium alloy AA5182 in the as-cast and hot isostatic pressing (HIP) states. The x-ray micro-tomography technique was used to observe that semi-solid deformation is accommodated by internal damage via growth of as-cast porosity and the nucleation of new damage-based voids. As the volume fraction of damage increases, the growth of voids occurs in an orientation perpendicular to the loading direction, both through expansion within the grain boundary liquid and via coalescence between voids. The damage then localizes, causing failure. The finite element semi-solid microstructural model was used to explore the effects of fraction solid, fraction porosity, and grain size on semi-solid constitutive behaviour. The simulations revealed that increased grain size and fraction porosity lead to a reduction in flow stress for a given fraction solid. Furthermore, local strain accumulation was linked to hot tearing, since strain localizes in the liquid very.

Download or read book Study of Hot Tearing in Cast and Wrought Aluminum Alloys written by Qinxin Wu and published by . This book was released on 2012 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: During the solidification process in casting, hot tearing may occur. It is a severe defect that normally involves the formation of a macroscopic tear, which generates cracks either on the surface or inside the casting. Over the past decades, many strategies have been developed to evaluate the hot tearing tendency. Unfortunately, most of the tests can only provide qualitative information. Therefore, a reliable and quantitative test to evaluate hot tearing in aluminum alloys is highly desirable. To address this issue, WPI and CANMET MTL (both members of the Light Metal Alliance) jointly developed a quantitative hot tearing test and established a specific methodology. Using a constrained rod mold, the hot tearing formation can be quantitatively studied by measuring the contraction force, time and temperature during solidification for a restrained casting or linear contraction, time and temperature for a relaxed casting. This study investigated cast aluminum alloys A380.1 and A390 and wrought aluminum alloys 6061 and 7075. The results show that wrought aluminum alloys have a much stronger hot tearing tendency than cast aluminum alloys based on a quantitative analysis. Also, the study involves the effects of adding strontium and oxides respectively into the cast aluminum alloy A380.1. Compared with the pure A380.1 alloy, the introduction of strontium decreases the hot tearing tendency, while the inclusion of oxide greatly increases the hot tearing. The information obtained through these tests provides a database of hot tearing phenomenon and establishes a new hot tearing index.

Download or read book Hot Deformation and Processing of Aluminum Alloys written by Hugh J. McQueen and published by CRC Press. This book was released on 2011-09-28 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive treatise on the hot working of aluminum and its alloys, Hot Deformation and Processing of Aluminum Alloys details the possible microstructural developments that can occur with hot deformation of various alloys, as well as the kind of mechanical properties that can be anticipated. The authors take great care to explain and differentiate hot working in the context of other elevated temperature phenomena, such as creep, superplasticity, cold working, and annealing. They also pay particular attention to the fundamental mechanisms of aluminum plasticity at hot working temperatures. Using extensive analysis derived from polarized light optical microscopy (POM), transmission electron microscopy (TEM), x-ray diffraction (XRD) scanning electron-microscopy with electron backscatter imaging (SEM-EBSD), and orientation imaging microscopy (OIM), the authors examine those microstructures that evolve in torsion, compression, extrusion, and rolling. Further microstructural analysis leads to detailed explanations of dynamic recovery (DRV), static recovery (SRV), discontinuous dynamic recrystallization (dDRX), discontinuous static recrystallization (dSRX), grain defining dynamic recovery (gDRV) (formerly geometric dynamic recrystallization, or gDRX), and continuous dynamic recrystallization involving both a single phase (cDRX/1-phase) and multiple phases (cDRX/2-phase). A companion to other works that focus on modeling, manufacturing involving plastic and superplastic deformation, and control of texture and phase transformations, this book provides thorough explanations of microstructural development to lay the foundation for further study of the mechanisms of thermomechanical processes and their application.

Download or read book Solidification and Casting written by G. J. Davies and published by . This book was released on 1973 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hot Tearing in Cast Aluminum Alloys Measures and Effects of Process Variables written by Shimin Li and published by . This book was released on 2010 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Hot tearing is a common and severe defect encountered in alloy castings and perhaps the pivotal issue defining an alloy's castability. Once it occurs, the casting has to be repaired or scraped, resulting in significant loss. Over the years many theories and models have been proposed and accordingly many tests have been developed. Unfortunately many of the tests that have been proposed are qualitative in nature; meanwhile, many of the prediction models are not satisfactory as they lack quantitative information, data and knowledge base. The need exists for a reliable and robust quantitative test to evaluate/characterize hot tearing in cast alloys. This work focused on developing an advanced test method and using it to study hot tearing in cast aluminum alloys. The objectives were to: 1) develop a reliable experimental methodology/setup to quantitatively measure and characterize hot tearing; and 2) quantify the mechanistic contributions of the process variables and investigate their effects on hot tearing tendency. The team at MPI in USA and CANMET-MTL in Canada has collaborated and developed such a testing setup. It consists mainly of a constrained rod mold and the load/displacement and temperature measuring system, which gives quantitative, simultaneous measurements of the real-time contraction force/displacement and temperature during solidification of casting. The data provide information about hot tearing formation and solidification characteristics, from which their quantitative relations are derived. Quantitative information such as tensile coherency, incipient crack refilling, crack initiation and propagation can be obtained. The method proves to be repeatable and reliable and has been used for studying the effects of various parameters (mold temperature, pouring temperature and grain refinement) on hot tearing of different cast aluminum alloys. In scientific sense this method can be used to study and reveal the nature of the hot tearing, for industry practice it provides a tool for production control. Moreover, the quantitative data and fundamental knowledge gained in this thesis can be used for validating and improving the existing hot tearing models.

Download or read book Hot Deformation of Aluminum Alloys III written by Z. Jin and published by Wiley-TMS. This book was released on 2003-01-01 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings address recent progress in theoretical and experimental studies of hot deformation of aluminum alloys. Technical papers from fundamental research and industrial applications cover such topics as hot deformation mechanisms, evolution of grain structure, texture, precipitates, and damage in thermomechanical processes including rolling, extrusion, forging, superplastic forming, friction stir welding, severe plastic deformation forming, hydroforming, and semi-solid forming. The design and optimization of thermomechanical processes and microstructure using fundamental understanding, development of models, and computer simulation are also addressed. A collection of papers from the 2003 TMS Annual Meeting and Exhibition, which was held in San Diego, California, March 2-6, 2003.

Download or read book A Study of Hot tearing During Solidification of Aluminum Alloys Via the Acoustic Emission Method written by Xiaojin Li and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study of Hot Tearing in Wrought Aluminium Alloys written by Shan Lin and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Enhanced Material Parts Optimization and Process Intensification written by Uwe Reisgen and published by Springer Nature. This book was released on 2021-03-07 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reports on topics at the interface between material processing, product and process optimization. It covers new developments and challenges in welding, brazing, cutting and coating, casting and molding, additive manufacturing, simulation and optimization techniques, as well as functional and structural materials and composites. Gathering authoritative contributions on the latest research and applications, presented at the International Joint Conference on Enhanced Material and Part Optimization and Process Intensification, EMPOrIA 2020, organized by SFB1120 Aachen, SFB814 Erlangen and CCE Darmstadt, on May 19–20, 2020, in Aachen, this book provides academics, students, and professionals with a timely snapshot of the main research trends, and extensive information on cutting-edge methods and technologies in materials, manufacturing and process engineering.

Download or read book Physical Metallurgy of Direct Chill Casting of Aluminum Alloys written by Dmitry G. Eskin and published by CRC Press. This book was released on 2008-04-17 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulling together information previously scattered throughout numerous research articles into one detailed resource, this book connects the fundamentals of structure formation during solidification with the practically observed structure and defect patterns in billets and ingots. The author examines the formation of a structure, properties, and defects in the as-cast material in tight correlation to the physical phenomena involved in the solidification and the process parameters. Compiling recent results and data, the book discusses the fundamentals of solidification together with metallurgical and technological aspects of DC casting. It gives new insight and perspective into DC casting research.

Download or read book A Study of Hot Tearing in Wrought Aluminum Alloys written by Shan Lin and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Weldability of Aluminum lithium Alloys written by Carl Edward Cross and published by . This book was released on 1986 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study of Hot Tearing in Wrought Aluminum Alloys written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Solidification of Aluminum Alloys written by Men G. Chu and published by Wiley-TMS. This book was released on 2004-03 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume addresses progress in the application of solidificationprinciples to the production of aluminum alloys. Topics includemicrostructure evolution, phase formation and solidification pathanalysis, grain refinement, micro/macro-segregation, mechanicalbehavior/properties in the mushy state, solidificationcracking/tearing, gas/shrinkage porosity formation, effect ofimpurities/trace elements, and the impact of cast structure on thesubsequent fabrication and properties of finished products. Paperson the experimental or theoretical simulation of solidificationaspects of casting processes including direct chill casting,continuous casting, shaped casting, semi-solid processing, andother advanced casting technologies are also included, as well asexamples showing the use of solidification principles to solveindustrial problems. From ahref="http://www.tms.org/Meetings/Annual-04/AnnMtg04Home.html"target="_blank"2004 TMS Annual Meeting/a to be held inCharlotte, North Carolina, March 14 - 18, 2004.

Download or read book Wear Mechanisms of Aluminium silicon Alloys written by J. Clarke and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mechanical Properties in the Semi solid State and Hot Tearing of Aluminum Alloys written by and published by . This book was released on 2004 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: