Thermodynamic Aspects of Tin Segregation during Solidification of Aluminium Alloys

2009 ◽  
Vol 618-619 ◽  
pp. 183-190 ◽  
Author(s):  
Rainer Schmid-Fetzer
Keyword(s):  
Experimental Data ◽  
Aluminium Alloys ◽  
Thermodynamic Database ◽  
Multicomponent Alloys ◽  
Scheil Simulation ◽  
Solidification Simulation ◽  
Software Packages

When trying to calculate the approximate constitution of as-cast tin containing aluminium alloys one has to cope with a combination of intricacies: (i) Scheil solidification simulation may reflect strong enrichment of alloying components, especially in multicomponent alloys, thus leaving the safe ground of the underlying thermodynamic database. (ii) Liquid demixing often intensifies by addition of many components to Al-Sn alloys, thus forming monotectic reactions, boosting the segregation and aggravating the first effect. (iii) Scheil simulation in multicomponent Al-x-y-z-Sn alloys not only combines the first two problems, moreover, the current versions of major thermodynamic software packages are not able to perform the Scheil simulation if liquid demixing and monotectic reactions occur. These intricacies are worked out and the development of a dedicated Al-Si-Cu-Mg-Sn thermodynamic database for large composition ranges is presented. Calculations are compared to experimental data of an Al-7.5Si-3.5Cu-0.3Mg-0.1Sn alloy and the need for specific follow-up work is identified.

scholarly journals Homogenisation Efficiency Assessed with Microstructure Analysis and Hardness Measurements in the EN AW 2011 Aluminium Alloy

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1211
Author(s):  
Maja Vončina ◽  
Aleš Nagode ◽  
Jožef Medved ◽  
Irena Paulin ◽  
Borut Žužek ◽  
...  
Keyword(s):  
Experimental Data ◽  
Image Analysis ◽  
Phase Equilibrium ◽  
Aluminium Alloy ◽  
Phase Formation ◽  
Aluminium Alloys ◽  
Eutectic Phase ◽  
The Matrix ◽  
Equilibrium Solidification ◽  
Homogenisation Process

When extruding the casted rods from EN AW 2011 aluminium alloys, not only their homogenized structure, but also their extrudable properties were significantly influenced by the hardness of the alloy. In this study, the object of investigations was the EN AW 2011 aluminium alloy, and the effect of homogenisation time on hardness was investigated. First, homogenisation was carried out at 520 °C for different times, imitating industrial conditions. After homogenisation, the samples were analysed by hardness measurements and further characterised by microscopy and image analysis to verify the influence of homogenisation on the resulting microstructural constituents. In addition, non-equilibrium solidification was simulated using the program Thermo-Calc and phase formation during solidification was investigated. The homogenisation process enabled more rounded shape of the Al2Cu eutectic phase, equilibrium formation of the phases, and the precipitation in the matrix, leading to a significant increase in the hardness of the EN AW 2011 aluminium alloy. The experimental data revealed a suitable homogenisation time of 4–6 h at a temperature of 520 °C, enabling optimal extrusion properties.

scholarly journals Workshop on Radio Transients

2011 ◽  
Vol 7 (S285) ◽  
pp. 272-272
Author(s):  
Steve Croft ◽  
Bryan Gaensler
Keyword(s):  
Best Practices ◽  
Common Ground ◽  
New Era ◽  
Software Packages ◽  
New Radio ◽  
The Status ◽  
Survey Strategy ◽  
Radio Transients ◽  
Single Pixel

SummaryWe are entering a new era in the study of variable and transient radio sources. This workshop discussed the instruments and the strategies employed to study those sources, how they are identified and classified, how results from different surveys can be compared, and how radio observations tie in with those at other wavelengths. The emphasis was on learning what common ground there is between the plethora of on-going projects, how methods and code can be shared, and how best practices regarding survey strategy could be adopted.The workshop featured the four topics below. Each topic commenced with a fairly brief introductory talk, which then developed into discussion. By way of preparation, participants had been invited to upload and discuss one slide per topic to a wiki ahead of the workshop.1. Telescopes, instrumentation and survey strategy. New radio facilities and on-going projects (including upgrades) are both studying the variability of the radio sky, and searching for transients. The discussion first centred on the status of those facilities, and on projects with a time-domain focus, both ongoing and planned, before turning to factors driving choices of instrumentation, such as phased array versus single pixel feeds, the field of view, spatial and time resolution, frequency and bandwidth, depth, area, and cadence of the surveys.2. Detection, pipelines, and classification. The workshop debated (a) the factors that influence decisions to study variability in the (u,v) plane, in images, or in catalogues, (b) whether, and how much, pipeline code could potentially be shared between one project and another, and which software packages are best for different approaches, (c) how data are stored and later accessed, and (d) how transients and variables are defined and classified.3. Statistics, interpretation, and synthesis. It then discussed how (i) the choice of facility and strategy and (ii) detection and classification schemes influence what is seen (in terms of types of object and rates) by different surveys, (iii) how results from different surveys could be compared, and (iv) how what we know from existing surveys drives choices (i) and (ii), particularly as regards finding new classes of object.4. Multiwavelength approaches. The workshop concluded by discussing what information is needed from wavelengths other than radio in order to classify transients and variables adequately and predict their rates as a function of topics (1), (2) and (3). It asked what the constraints are on responding to, and issuing triggers for, follow-up observations, and how that might feed back into considerations for designing our telescopes and surveys.

Thermodynamic Calculation of the Liquidus Projections of the Al-Cu-Fe-Mg, Al-Cu-Mg-Si, and Al-Fe-Mg-Si Quaternary Systems on Al-Rich Corner

2020 ◽  
Vol 993 ◽  
pp. 1031-1042
Author(s):  
Jing Rui Zhao ◽  
Yong Du ◽  
Li Jun Zhang ◽  
Shu Hong Liu ◽  
Jin Huan Xia ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aluminum Alloys ◽  
Liquidus Projection ◽  
Thermodynamic Calculation ◽  
Theoretical Basis ◽  
Solidification Process ◽  
Material Design ◽  
Calphad Method ◽  
Quaternary Systems ◽  
Solidification Simulation

The thermodynamic calculations of Al-Cu-Fe-Mg, Al-Cu-Mg-Si and Al–Fe–Mg–Si quaternary systems were carried out using CALPHAD method, based on the Al–Cu–Fe–Mg–Si thermodynamic database. The liquidus projection of Al–Cu–Fe–Mg, Al–Cu–Mg–Si and Al–Fe–Mg–Si quaternary systems at Al-rich corner were constructed, and the solidification structures of Al-12Cu-7Mg-1Fe, Al-14Cu-2Mg-4Si, Al-0.3Fe-6Mg-12Si (wt.%) alloys were analyzed by the Scheil solidification simulation. The calculated results agree well with the previous experimental data. The liquidus projections of three quaternary aluminum alloys at the Al-rich corner were accurately plotted, which could be helpful for the analysis of solidification process of multicomponent alloy systems, and provide an important theoretical basis for the material design of aluminum alloys.

scholarly journals The thermodynamic database COST MP0602 for materials for high-temperature lead-free soldering

2012 ◽  
Vol 48 (3) ◽  
pp. 339-346 ◽  
Author(s):  
A. Kroupa ◽  
A. Dinsdale ◽  
A. Watson ◽  
J. Vrestal ◽  
A. Zemanova ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermodynamic Data ◽  
Ternary Systems ◽  
Thermodynamic Modelling ◽  
Thermodynamic Database ◽  
Lead Free ◽  
Commercial Software ◽  
Current State ◽  
Software Packages ◽  
Thermodynamic Databases

The current state of thermodynamic modelling in the field of high-temperature lead-free soldering is presented. A consistent thermodynamic database, containing 18 elements (Ag, Al, Au, Bi, Co, Cu, Ga, Ge, Mg, Ni, P, Pb, Pd, Sb, Sn, Ti and Zn) has been created. The thermodynamic data for the most of the important binary and selected ternary systems were checked and included into the database. The database was tested using major commercial software packages. Such reliable and sophisticated software coupled to reliable thermodynamic databases are necessary prerequisites for application of thermodynamics in advanced alloys design.

The Development and Validation of a New Thermodynamic Database for Aluminium Alloys

2012 ◽  
pp. 291-295 ◽  
Author(s):  
A. Markström ◽  
Y Du ◽  
S. H. Liu ◽  
L. J. Zhang ◽  
P. Mason ◽  
...  
Keyword(s):  
Aluminium Alloys ◽  
Thermodynamic Database ◽  
Development And Validation

Software packages for automation of environmental monitoring and experimental data processing

2018 ◽  
pp. 273-278 ◽  
Author(s):  
K.J. Kachiashvili ◽  
D.G. Gordeziani ◽  
D.Yu. Melikdzhanian ◽  
V.I. Khuchua ◽  
V.A. Stepanishvili
Keyword(s):  
Experimental Data ◽  
Data Processing ◽  
Environmental Monitoring ◽  
Experimental Data Processing ◽  
Software Packages

Thermodynamic Database of the Phase Diagrams in the Sc-X Binary Systems

2016 ◽  
Vol 850 ◽  
pp. 439-443 ◽  
Author(s):  
Jia Lian Li ◽  
Shu Liang Wang ◽  
Xue Qin ◽  
Yu Heng Li ◽  
Lu Jiang Zhou ◽  
...  
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Phase Diagrams ◽  
Binary Systems ◽  
Regular Solution Model ◽  
Thermodynamic Database ◽  
Free Energies ◽  
Positive Effects ◽  
Sc Addition ◽  
Welding Properties

Sc-based alloys have been used as aero-structures materials, and Sc addition on wrought alloys has positive effects on weldability and welding properties. Phase diagrams play an effective role during the development of new type of alloy with good properties. Therefore, to establish the thermodynamic database of Sc-X binary systems is important and necessary.In the present work, the thermodynamic assessments of Sc-X (Ag, B, Cr, Er, Gd, Mo, Th, W, Y, Zr) binary systems was carried out by using CALPHAD (Calculation of Phase Diagrams) method based on the experimental data including thermodynamic properties and phase equilibria. The Gibbs free energies of the solution phases were described by the sub-regular solution model with the Redlich-Kister equation, and those of the intermetallic compounds were described by the sub-lattice model. A set of self-consistent thermodynamic parameters were derived for describing the Gibbs free energies of each solution phase and intermetallic compound. The calculated phase diagrams and thermodynamic properties are in good agreement with experimental data. The thermodynamic database of the Sc-X (Al, Ag, B, Ca, Co, Cr, Cu, Er, Fe, Ga, Gd, Ge, La, Li, Mg, Mn, Mo, Ni, Pb, Pd, Ru, Sn, Th, W, Y, Zn, Zr) binary systems have been developed, which can provide much important thermodynamic information for multicomponent Al-Sc based alloys.

Entall - Thermodynamic Database of Alloys

2013 ◽  
Vol 58 (4) ◽  
pp. 1147-1148 ◽  
Author(s):  
A. Dębski
Keyword(s):  
Experimental Data ◽  
Thermodynamic Property ◽  
Enthalpy Of Formation ◽  
Thermodynamic Functions ◽  
Intermetallic Phases ◽  
Metal Alloy ◽  
Thermodynamic Database ◽  
Property Data ◽  
The Enthalpy Of Formation ◽  
Alloy Systems

Abstract Li-Si, Ag-Ca, B-Li, Ca-Li and Al-Li belong to the group of application alloys. The Entall database includes experimental data on the enthalpy of formation of the intermetallic phases belonging to the mentioned systems, as well as software for the calculation of other thermodynamic functions. The presented Entall database is the first proposal of a thermodynamic property data, which will be gradually extended by new metal alloy systems. It is a free database, available at www.entall.imim.pl.

A Thermodynamic Database for Fe-Cr-Mn-Ni-Ti-S-C-N System

2005 ◽  
Vol 500-501 ◽  
pp. 711-718 ◽  
Author(s):  
Katsunari Oikawa ◽  
Hajime Mitsui ◽  
Kiyohito Ishida
Keyword(s):  
Complex System ◽  
Experimental Data ◽  
Phase Diagram ◽  
Thermodynamic Properties ◽  
Stainless Steels ◽  
Carbon Steels ◽  
Thermodynamic Database ◽  
Low Carbon ◽  
Low Carbon Steels ◽  
Good Agreement

A database for thermodynamic information of sulfides and carbo-sulfide in steels has been developed, where the thermodynamic properties of the relevant constituting sub-system of the complex system have been assessed by the CALPHAD (Calculation of Phase Diagrams) approach. The utility of this database is demonstrated in examples of phase diagram calculations of low carbon steels and stainless steels. The calculated results are in good agreement with experimental data. The developed thermodynamic database would be useful in predicting the formation of sulfides and carbo-sulfides in the commercial steels.

scholarly journals Partial monopolar transfer of pectoralis major for elbow active flexion restoration in children with arthrogryposis

2021 ◽  
Vol 9 (4) ◽  
pp. 407-416
Author(s):  
Olga E. Agranovich ◽  
Ekaterina V. Petrova ◽  
Sergey F. Batkin ◽  
Evgeniya I. Ermolovich ◽  
Igor A. Komolkin ◽  
...  
Keyword(s):  
Biceps Brachii ◽  
Pectoralis Major Muscle ◽  
Elbow Flexion ◽  
Pectoralis Major ◽  
Software Packages ◽  
Active Flexion ◽  
Before And After ◽  
The Mean ◽  
Elbow Motion

BACKGROUND: One of the main problems that limited or made the self-ability of patients with arthrogryposis impossible is the lack of active elbow flexion due to hypoplasia (or aplasia) of the forearm flexors and, especially the m. biceps brachii. AIM: To evaluate the possibility of active forearm flexion restoration in children with arthrogryposis by partial monopolar transposition of the pectoralis major muscle. MATERIALS AND METHODS: Elbow active flexion restoration by partial monopolar transposition of the pectoralis major muscle to biceps brachii was conducted in 34 children with arthrogryposis (39 upper limbs) from 2011 to 2020. The muscle autograft included a fragment of the fascia of the m. rectus abdominis. Clinical examinations of patients were performed before and after the operation. Statistical data processing was performed using the software packages Statistica 10 and SAS JMP 11. RESULTS: The follow-up results were estimated from 6 to 99 months (44.53 31.72) postoperative. The mean age of patients was 6.24 4.24 years. The active postoperative elbow motion was 0120 (71.94 33.40). The passive postoperative elbow motion did not change and was 90130 (104.12 12.40). Muscles strength after the operation was grade 25. Elbow extension was limited in 30 cases (76.9%) from 0 to 40 (21.70 12.27) without problem in the activities of daily living. Good results were determined in 15 cases (38.5%), satisfactory in 8 (20.5%), and poor in 16 (41%). CONCLUSIONS: This study revealed that our partial monopolar transfer of pectoralis major to biceps brachii technic restored sufficient forearm flexion and improved self-ability without forming severe elbow flexor contractures of more than half of the patients with arthrogryposis.

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