2 edition of Constitutive acoustic-emission elastic-stress behavior of magnesium alloy found in the catalog.
Constitutive acoustic-emission elastic-stress behavior of magnesium alloy
Williams, James H.
by National Aeronautics and Space Administration, Springfield, Va., for sale by the National Technical Information Service in Washington
Written in English
|Statement||James H. Williams, jr., and George P. Emerson.|
|Series||NASA contractor report ; NASA CR-2839, NASA contractor report -- NASA CR-2839.|
|Contributions||Emerson, George P., United States. National Aeronautics and Space Administration.|
|The Physical Object|
|Pagination||39 p. :|
|Number of Pages||39|
Purchase Advances in Mechanical Behaviour, Plasticity and Damage - 1st Edition. Print Book & E-Book. ISBN , Agnew SR, Viswanathan S, Payzant, Han Q, Liu KC, Kenik EA () Tensile and Compressive Creep Behavior of Magnesium Die Casting Alloys Containing Aluminium. In Kainer KU (ed) Magnesium Alloys and their Applications. Wiley VCH Verlag Gmbh, .
Structure Evolution in BCC Pure Metals and Alloys / Analysis of the Constitutive Behavior of a Fictitious BCC Alloy: UfKonel / Analysis of the Constitutive Behavior of AISI Steel / Analysis of the Constitutive Behavior of Polycrystalline Vanadium / Deformation Twinning in Vanadium / The matrix materials used in this investigation were Mg of commercial purity, magnesium alloys ZE41 alloy containing 4 wt. % Zn and 1 wt. % rare earths, an AZ91 alloy containing 9 wt. % Al and 1 wt. % Zn, a QE22 alloy containing 2 wt. % Ag and 2 wt. % rare earths and an AM
N2 - The following study investigates the deformation behavior and acoustic emission in aluminum-magnesium alloy under conditions of non-isothermal thermo-mechanical loading. The accumulation of deformation in the alloy, in conditions of change from room temperature to °C, occurs in two temperature intervals (I, II), characterized by. A magnesium alloy engine block has the potential to significantly reduce the weight of an automobile, and studies on the corrosion of magnesium alloys in automotive coolants has received increasing attention. Song and StJohn studied the corrosion of a new magnesium alloys AM-SC1 and magnesium alloy AZ91 in commercial engine coolants. AM-SC1 is.
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Constitutive acoustic-emission elastic-stress behavior of magnesium alloy. Washington: National Aeronautics and Space Administration: Springfield, Va.: For. CONSTITUTIVE ACOUSTIC-EMISSION ELASTIC-STRESS BEHAVIOR OF MAGNESIUM ALLOY James H. Willidms, JR, mzd George P, Emerson ___ ’ ‘.
Prepared by MASSACHUSETTS INSTITUTE OF TECHNOLOGY!I Cambridge, Mass. 02 for Lewis Research Center NATIONAL AERONAUTICS AND SPACE ADMINISTRATION l WASHINGTON, D.
l JUNE Constitutive acoustic-emission elastic-stress behavior of magnesium alloy. An acoustic emission Bauschinger strain model is proposed to describe the unloading emission behavior. For the limited range of stress examined, loading and unloading stress delays of the order of 50 MN/sq m are observed, and they appear to be dependent upon the Author: G.
Emerson and Jr. Williams. These models require prior knowledge of magnesium’s constitutive behavior in the as-cast state over a wide range of temperatures and strain rates.
While research has been performed to characterize AZ31 under compressive loading and in the fully solid state (e.g. , ), little is known regarding the semi-solid constitutive behavior of Cited by: The hot deformation behaviors of AZ41M magnesium alloy were studied via hot compression tests on a GleebleD thermal-mechanical simulation machine under the strain rate of –1 s −1 and deformation temperature of – K.
According to the experimental results, the flow stress curves show a quintessential flow behavior with dynamic recrystallization softening as the Cited by: However, due to the unusual mechanical behavior of magnesium alloys, accurate constitutive modeling of these alloys is still a challenging task.
Several continuum based approaches have been used to model the tension/compression asymmetry associated with HCP materials by introducing eccentricity of the yield surface (Lee and Backofen, Constitutive modeling of the magnesium alloy behavior, however, is rather a challenging task because magnesium alloy sheets exhibit unique behavior compared to cubic metals.
At room temperature, magnesium alloy sheets have significant anisotropy that deviates from conventional predictions using von Mises or Hill yield surfaces (Kelley and.
Constitutive acoustic-emission elastic-stress behavior of magnesium alloy. July The existence of acoustic emission elastic stress constitutive relations is concluded, which provides.
Another characteristic behavior of Mg alloy sheets is a strong inelastic response during unloading, which is the main topic of this study. Fig. 1 shows the stress–strain curves obtained from uniaxial tensile tests of Mg alloy, mild steel, and aluminum alloy sheets.
Clearly the Mg alloy sheet exhibits a strong inelastic deformation during unloading, and the gradient during unloading is.
Título: Constitutive acoustic-emission elastic-stress behavior of magnesium alloy Creador: James H. Williams Género: Acoustic emission Impresora: no defined Identidad Clave: KZpP_gah2pMC Código del libro: UIUC Oficiales de Idiomas: UIUC El número de hojas: 39 Lanzamiento: To accurately predict the material behavior of a magnesium alloy from the microstructural level, the VPSC crystal plasticity model was used as a constitutive equation in this methodology.
The constitutive response of a commercial magnesium alloy rolled sheet (AZ31B-O) is studied based on room temperature tensile and compressive tests at strain rates ranging from 10 −3 to 10 3 s −e of its strong basal texture, this alloy exhibits a significant tension–compression asymmetry (strength differential) that is manifest further in terms of rather different strain rate.
Texture development in magnesium alloy AZ31 was studied by uniaxial compression tests at temperatures, strain rates and final strains ranging from to K, × 10−3 to × 10−5 s. The influence of grain size on the flow stress of magnesium alloys has been subject of a number of investigations (e.g.
Mabuchi et al.,Anderson et al., ). Choi and co-workers (Choi et al., ) studied the deformation behaviour of ball milled Mg with the grain size from 60 nm up to 1 μm. The following study investigates the deformation behavior and acoustic emission in aluminum-magnesium alloy under conditions of non-isothermal thermo-mechanical loading.
The accumulation of deformation in the alloy, in conditions of change from room temperature to °C, occurs in two temperature intervals (I, II), characterized by different rates of deformation.
Based on the stress–strain curves of as cast Mg-8Gd-3Y alloy, which were obtained by isothermal compression tests at temperatures ranging from °C to °C and strain rates from to s−1, a new constitutive model for thermal deformation of magnesium alloys was proposed from the functional relationship between the ratio of instantaneous stress to peak stress (σ/σp) and that.
A constitutive law is offered for an AZ31B-H24 Mg alloy within a strain rate range of 10−5−10−2 s−1 at a temperature of °C. The constitutive law, which is developed by curve fitting.
Study on the Indentation Creep Behavior of Mg-4Al-RECa Magnesium Alloy Article (PDF Available) in Journal of Materials Engineering and Performance 24(11) October with 59 Reads. Casting magnesium alloys are heterogeneous materials containing numerous voids.
Assuming the voids are spherical, in the present investigation, the evolution equations of the growth and nucleation of the voids have been presented. Combining the evolution equation of the void growth with that of the void nucleation, the evolution rule of the voids was obtained.
Abstract. Magnesium alloys with different content of zinc (Zn) and yttrium (Y) were extruded at an extrusion ratio of at °C. The alloying elements in both Mg alloys formed a long period stacking ordered (LPSO) phase, which during the extrusion process was elongated along the extrusion direction (ED).
Uniaxial tensile tests were carried out in the temperature range of –°C and the strain rate range of ×10−3–×10−1 s−1 to evaluate the superplasticity of AZ31 Mg alloy. The threshold stress which characterizes the difficulty for grain boundary sliding was calculated at various temperatures.
The surface relieves of superplastically deformed specimens were observed by.Abstract. Our community has learned a great deal about twinning in Mg alloys over the past decade.
Some of these things were known qualitatively in prior decades, but we have now developed a proficiency in characterization and computational modeling which permits a quantitative description of these twinning-induced effects over a wide range of strain rates, temperatures, loading conditions.Magnesium alloys have been increasingly used in automotive and electronic industries because of their excellent strength to weight ratio and EMI shielding properties.
However, magnesium alloys have low formability at room temperature due to their unique mechanical behavior (twinning and untwining), prompting for forming at an elevated temperature. In this study, a temperature dependent.