The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform

R. K. W. Marceau - One of the best experts on this subject based on the ideXlab platform.

  • atomic scale analysis of Light Alloys using atom probe tomography
    Materials Science and Technology, 2016
    Co-Authors: R. K. W. Marceau
    Abstract:

    The present paper reviews recent progress in atomic-scale characterisation of composition and nanostructure of Light alloy materials using the technique of atom probe tomography. In particular, the present review will highLight atom-by-atom analysis of solid solution architecture, including solute clustering and short-range order, with reference to current limitations of spatial resolution and detector efficiency of atom probe tomography and methods to address these limitations. This leads to discussion of prediction of mechanical properties by simulation and modelling of the strengthening effect exerted by solute clusters and the role of experimental atom probe data to assist in this process. The unique contribution of atom probe tomography to the study of corrosion and hydrogen embrittlement of Light Alloys will also be discussed as well as a brief insight into its potential application for the investigation of solute strengthening of twinning in Mg Alloys.

  • Atomic-scale analysis of Light Alloys using atom probe tomography
    Materials Science and Technology, 2015
    Co-Authors: R. K. W. Marceau
    Abstract:

    © 2016 Institute of Materials. The present paper reviews recent progress in atomic -=-scale characterisation of composition and nanostructure of Light alloy materials using the technique of atom probe tomography. In particular, the present review will highLight atom by atom analysis of solid solution architecture, including solute clustering and short range order, with reference to current limitations of spatial resolution and detector efficiency of atom probe tomography and methods to address these limitations. This leads to discussion of prediction of mechanical properties by simulation and modelling of the strengthening effect exerted by solute clusters and the role of experimental atom probe data to assist in this process. The unique contribution of atom probe tomography to the study of corrosion and hydrogen embrittlement of Light Alloys will also be discussed as well as a brief insight into its potential application for the investigation of solute strengthening of twinning in Mg Alloys.

Mohammad Azadi - One of the best experts on this subject based on the ideXlab platform.

  • Cyclic thermo-mechanical stress, strain and continuum damage behaviors in Light Alloys during fatigue lifetime considering heat treatment effect
    International Journal of Fatigue, 2017
    Co-Authors: Mohammad Azadi
    Abstract:

    Abstract In this article, thermo-mechanical fatigue behaviors in Light Alloys have been investigated to find the effect of heat treatments. For this objective, thermo-mechanical fatigue tests were performed on the A356.0 aluminum alloy and the AZE911 magnesium alloy, with and without typical T6 heat treatments. Obtained results demonstrated no significant difference in thermo-mechanical fatigue lifetime of the A356.0 alloy between non-heat-treated and heat-treated test specimens at 250 °C of the maximum temperature, which was attributed to the over-ageing phenomenon. As a consequence, this low effect showed that the heat treatment could be eliminated for cylinder heads. However, the thermo-mechanical fatigue lifetime of the AZE911 alloy was significantly affected by the heat treatment. The explanation for the mentioned behavior could be found in the material micro-structure, which was affected by dissolving the brittle intermetallic phase in the matrix of the AZE911 alloy. However, the magnesium alloy still requires more improvements in the fatigue lifetime for a possible substitution in cylinder heads. Continuum damage behaviors showed that higher damage values occurred in the aluminum alloy, in comparison to the magnesium alloy, both for heat-treated and non-heat-treated specimens.

  • numerical simulations of cyclic behaviors in Light Alloys under isothermal and thermo mechanical fatigue loadings
    Materials & Design, 2014
    Co-Authors: G H Farrahi, A Shamloo, M Felfeli, Mohammad Azadi
    Abstract:

    Abstract In this article, numerical simulations of cyclic behaviors in Light Alloys are conducted under isothermal and thermo-mechanical fatigue loadings. For this purpose, an aluminum alloy (A356) which is widely used in cylinder heads and a magnesium alloy (AZ91) which can be applicable in cylinder heads are considered to study their stress–strain hysteresis loops. Two plasticity approaches including the Chaboche’s hardening model and the Nagode’s spring-slider model are applied to simulate cyclic behaviors. To validate obtained results, strain-controlled fatigue tests are performed under low cycle and thermo-mechanical fatigue loadings. Numerical results demonstrate a good agreement with experimental data at the mid-life cycle of fatigue tests in Light Alloys. Calibrated material constants based on low cycle fatigue tests at various temperatures are applied to models to estimate the thermo-mechanical behavior of Light Alloys. The reason is to reduce costs and the testing time by performing isothermal fatigue experiments at higher strain rates.

  • Thermo-mechanical behaviours of Light Alloys in comparison to high temperature isothermal behaviours
    Materials at High Temperatures, 2014
    Co-Authors: Mohammad Azadi, Gholam Hossein Farrahi, Gerhard Winter, W. Eichlseder
    Abstract:

    In this article, out-of-phase thermo-mechanical fatigue (TMF) behaviours of Light Alloys were investigated in comparison to their high temperature low cycle fatigue (LCF) behaviours. For this objective, strain based fatigue tests were performed on the A356 aluminium alloy and on the AZ91 magnesium alloy. Besides, TMF tests were carried out, where both strain and temperature changed. The fatigue lifetime comparison demonstrated that the TMF lifetime was less than that one under LCF loadings at elevated temperatures for both Light Alloys. The reason was due to severe conditions in TMF tests in comparison to LCF tests. The temperature varied in TMF test but it was constant under LCF loadings. As the other reason, the tensile mean stress occurred under TMF loadings, in comparison to the compressive mean stress under LCF loadings. At high temperatures, the cyclic hardening behaviour occurred in the AZ91 alloy and the A356 alloy had the cyclic softening behaviour.

G I Eskin - One of the best experts on this subject based on the ideXlab platform.

  • broad prospects for commercial application of the ultrasonic cavitation melt treatment of Light Alloys
    Ultrasonics Sonochemistry, 2001
    Co-Authors: G I Eskin
    Abstract:

    Abstract Theoretical and applied aspects of ultrasonic melt treatment are considered. Industrial applications of the cavitation treatment for degassing, filtration, and grain refinement are illustrated using data for commercial Alloys. Some new fields of use such as semi-solid processing, low-friction Alloys, and natural composites are discussed. In general, wide prospects of commercial application for the ultrasonic melt treatment of Light Alloys are shown.

  • New aspects of the plastic deformation of Light Alloys in the thixotropic state
    Metallurgist, 1998
    Co-Authors: G I Eskin
    Abstract:

    Ultrasonic (cavitational) treatment of the melt during continuous casting makes it possible to form a limitingly fine nondendritic structure, which opens up new possibilities for the process of semi-solid deformation. The deformation process is made easier and the treatment eliminates the need for the additional operation of converting the fine-grained dendritic structure of the ingot into a coarse nondendritic structure by heating the metal in the semi-solid state. The process can be used for the die-forging of complex parts made of high-strength structural aluminum Alloys of the system Al-Zn-Mg-Cu-Zr.

  • principles of ultrasonic treatment application for Light Alloys melts
    Advanced Performance Materials, 1997
    Co-Authors: G I Eskin
    Abstract:

    Scientific and practical aspects of ultrasonic treatment of Light alloy melts followed with development of acoustic cavitation in liquid metals are discussed. It is shown, that the ultrasonic melt treatment raises the rate of degassing and fine filtration of Light alloy melts and very strongly effects ingot structure. Furthermore, an inherited effect of ultrasonic melt treatment on the structure and properties of wrought Light alloy semis is shown.

  • influence of cavitation treatment of melts on the processes of nucleation and growth of crystals during solidification of ingots and castings from Light Alloys
    Ultrasonics Sonochemistry, 1994
    Co-Authors: G I Eskin
    Abstract:

    Abstract Actual melts of Light Alloys contain a large amount of insoluble impurities; for aluminium and its Alloys these are mainly oxides of the Al 2 O 3 type, so one could not consider such melts as the ideal liquid. As a rule, the most part of the impurities is represented by insoluble particles ⩽ 1.0 μ m in size. These impurities being nonwettable by the melt do not take part in the solidification process. Generation of cavitation bubbles, their nonlinear pulsation and compression, surface distortion, and formation of new bubbles from fragments of the former ones result in the appearance of impact pulses of pressure and cumulative jets. Under such conditions of the active cavitation treatment of the melt, defects on oxide particle surfaces filled with the matrix melt ensure the transformation of these noncontrolled impurities to active solidification nuclei. This paper focuses especially on the features of the attainment of the extremely refined cast grain structure and the transition to nondendritic solidification of aluminium Alloys ingots in acoustic cavitation field.

G A Chadwick - One of the best experts on this subject based on the ideXlab platform.

  • squeeze casting of Light Alloys and their composites
    Journal of Materials Processing Technology, 1996
    Co-Authors: G A Chadwick
    Abstract:

    Abstract Squeeze casting is the term used commonly to describe processes in which liquid metal is solidified under the action of a relatively high external pressure. The fundamentals of the process have been known for decades, the process having been used in Russia for more than 50 years. However, it is only recently that squeeze casting has been commercialised in the West to produce high-quality engineering components with, and without, reinforcements. This article reviews aspects of recent progress in the development of current squeeze-casting techniques, and addresses both the merits and limitations of the various processes. The relationships between the microstructure and mechanical properties of some squeeze-cast Light Alloys, as well as their metal-matrix composite (MMC) counterparts, are presented, and the distinguished advantage of being able to directly squeeze cast high-strength aerospace wrought Alloys, thus replacing forgings by casting, is highLighted.

H. M. Flower - One of the best experts on this subject based on the ideXlab platform.

  • Light Alloys: metallurgy of the Light metals
    International Materials Reviews, 1992
    Co-Authors: H. M. Flower
    Abstract:

    Thoroughly revised and updated, this third edition of lan Polmear’s Light Alloys provides the definitive overview of the metallurgy of aluminum, magnesium and titanium Alloys. The emphasis remains on manufacturing processes and application areas, in which there have been significant advances in recent years. The extraction of each metal is considered briefly, followed by its casting characteristics and alloying behavior. Sections on heat treatment properties, fabrication and major applications have been expanded to give more comprehensive coverage of the subjects. Particular attention has been paid to microstructure/property relationships as well as to the role of the individual alloying elements, and new materials and novel processes are reviewed in an additional chapter. This succinct and informative introduction to the physical metallurgy of the Light Alloys will be essential reading for advanced undergraduates in metallurgy, materials science, manufacturing and mechanical engineering. It will also prove invaluable to metallu## gists and engineers in industry seeking to expand on their knowledge. Other Titles of Interest Steels: Microstructure and Properties Second Edition R W K Honeycombe and H K D H Bhadeshia ISBN 0340589469 Properties of Engineering Materials Second Edition R A Higgins ISBN 0 340 60033 0 Engineering Metallurgy: Applied Physical Metallurgy Sixth Edition R H Higgins ISBN 0 340 56830 5