Influence of Specimen Notices on the Superplastic m-δ Relationship of Zn-Ni-Mg Alloy

MRS Proceedings ◽

10.1557/proc-196-271 ◽

1990 ◽

Vol 196 ◽

Author(s):

Chin Liu ◽

Tao Jin

Keyword(s):

Strain Rate ◽

Mg Alloy ◽

Notch Effect ◽

Image Position ◽

Relationship Of

ABSTRACTWith AM/Ao = 1, the superplastic m- δ curves of Zn-Ni-Mg alloy have been studied. When T=220°C and έ (initial)=1.33×10−2 min−1, the curve was of the type. It was transformed into the mL =mmin =mo<mF,δL=δL<εF type of curve, when T=200°–230°C and έ (initial)=3.33×10−2 min−1 and further transformed the type at 240°–250°C with the same strain rate.With AN/Ao<1 and >0.595, T=230°C and έ (initial)=3.33×10−2 min−1 the curves were all of the mL=mmax =mo <mF, δ.(=O)= δL < δF type. The δF values increased with increase in AN/Ao value. The effect mainly reflected on the CF value and the CL m-δ equation can be expressed to account for the notch effect as follows:where and AN/Ao < 1 and > 0.595.Symbols: Refer to the List of Symbols.

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A Modified Peric Model for Al-Mg Alloy Sheet with Rate-Independent Initial Yield Stress at Warm Temperatures

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.287.3 ◽

2019 ◽

Vol 287 ◽

pp. 3-7

Author(s):

Yong Zhang ◽

Qing Zhang ◽

Yuan Tao Sun ◽

Xian Rong Qin

Keyword(s):

Flow Stress ◽

Plastic Strain ◽

Strain Rate ◽

Yield Stress ◽

Constitutive Models ◽

Mg Alloy ◽

Initial Yield Stress ◽

Initial Yield ◽

Rate Dependent ◽

Dependent Flow

The constitutive modeling of aluminum alloy under warm forming conditions generally considers the influence of temperature and strain rate. It has been shown by published flow stress curves of Al-Mg alloy that there is nearly no effect of strain rate on initial yield stress at various temperatures. However, most constitutive models ignored this phenomenon and may lead to inaccurate description. In order to capture the rate-independent initial yield stress, Peric model is modified via introducing plastic strain to multiply the strain rate, for eliminating the effect of strain rate when the plastic strain is zero. Other constitutive models including the Wagoner, modified Hockett–Sherby and Peric are also considered and compared. The results show that the modified Peric model could not only describe the temperature-and rate-dependent flow stress, but also capture the rate-independent initial yield stress, while the Wagoner, modified Hockett–Sherby and Peric model can only describe the temperature-and rate-dependent flow stress. Moreover, the modified Peric model could obtain proper static yield stress more naturally, and this property may have potential applications in rate-dependent simulations.

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Slaves to Rome: The Rhetoric of Mastery in Titus' Speech to the Jews (Bellum Judaicum 6.328-50)

Ramus ◽

10.1017/s0048671x00000771 ◽

2007 ◽

Vol 36 (1) ◽

pp. 25-38 ◽

Cited By ~ 2

Author(s):

Myles Lavan

Keyword(s):

Historical Account ◽

Self Presentation ◽

Image Position ◽

Relationship Of ◽

The Relationship ◽

Made In

(BJ6.350)Those who discard their weapons and surrender their persons, I will let live. Like a lenient master in a household, I will punish the incorrigible but preserve the rest for myself.So ends Titus' address to the embattled defenders of Jerusalem in the sixth book of Josephus'Jewish War(6.328-50). It is the most substantial instance of communication between Romans and Jews in the work. Titus compares himself to the master of a household and the Jewish rebels to his slaves. Is this how we expect a Roman to describe empire? If not, what does it mean for our understanding of the politics of Josephus' history? The question is particularly acute given that this is not just any Roman but Titus himself: heir apparent and, if we believe Josephus, the man who read and approved this historical account. It is thus surprising that, while the speeches of Jewish advocates of submission to Rome such as Agrippa II (2.345-401) and Josephus himself (5.362-419) have long fascinated readers, Titus' speech has received little or no attention. Remarkably, it is not mentioned in any of three recent collections of essays on Josephus. This paper aims to highlight the rhetorical choices that Josephus has made in constructing this voice for Titus—particularly his self-presentation as master—and the interpretive questions these raise for his readers. It should go without saying that the relationship of this text to anything that Titus may have said during the siege is highly problematic. (Potentially more significant, but unfortunately no less speculative, is the question of how it might relate to any speech recorded in the commentaries of Vespasian and Titus that Josephus appears to have used as a source.) What we have is a Josephan composition that is embedded in the broader narrative of theJewish War.

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High Strain Rate Superplasticity of Powder Metallurgy Si3N4 Reinforced Al-Zn-Mg Alloy Composites.

Journal of the Japan Society of Powder and Powder Metallurgy ◽

10.2497/jjspm.42.758 ◽

1995 ◽

Vol 42 (6) ◽

pp. 758-761 ◽

Cited By ~ 7

Author(s):

Mamoru Mabuchi ◽

Kenji Higashi

Keyword(s):

Powder Metallurgy ◽

High Strain Rate ◽

Strain Rate ◽

High Strain ◽

Mg Alloy

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Aging behavior of the extruded SiCp-reinforced AZ91 Mg alloy composite

Journal of Materials Research ◽

10.1557/jmr.2018.427 ◽

2018 ◽

Vol 34 (2) ◽

pp. 335-343

Author(s):

Hai Chang ◽

Xiaoshi Hu ◽

Xiaojun Wang ◽

Junfeng Du ◽

Libo Tong

Keyword(s):

Mg Alloy ◽

Alloy Composite ◽

Aging Behavior ◽

Image Position

Abstract

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Longitudinal Stress Gradients and Basal Shear Stress of a Temperate Valley Glacier

Journal of Glaciology ◽

10.1017/s0022143000015148 ◽

1979 ◽

Vol 24 (90) ◽

pp. 507-508 ◽

Cited By ~ 2

Author(s):

Robert Bindschadler

Keyword(s):

Shear Stress ◽

Strain Rate ◽

Field Data ◽

Numerical Models ◽

Lateral Strain ◽

Longitudinal Stress ◽

Base Shear ◽

Stress Gradients ◽

Valley Glacier ◽

Image Position

AbstractFor the first time field data from a temperate valley glacier, the Variegated Glacier, are used to investigate the behavior of longitudinal stress gradients predicted by the relation(1)whereHis the local depth, andysandybare the surface and bed elevations respectively. This equation is similar to one derived by Budd (1970) for plane strain-rate, to evaluate the importance of longitudinal stress gradients, but a shape factorfis included to account approximately for lateral strain-rate gradients. Predictive numerical models of valley glaciers require the local base shear stress to be known as accurately as possible. It has been argued on theoretical grounds that whenTis averaged over distances of more than five to ten times the depth, this term is negligible. At larger averaging scales, 2Gcan then be considered a correction to the simple geometric expression of base stress due to the presence of longitudinal stress gradients. Field data of velocity and geometry are used to evaluate the terms of Equation (1), whereτband 2Gare estimated asandat intervals of 100 m,Usis the measured surface center-line velocity,Aandnare the flow-law parameters, andis the surface longitudinal strain-rate. The expression for 2Gis an approximation proposed by Budd (1970).

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Effect of temperature and strain rate on the mechanisms of indentation deformation of magnesium

MRS Communications ◽

10.1557/mrc.2015.57 ◽

2015 ◽

Vol 5 (3) ◽

pp. 513-518 ◽

Cited By ~ 8

Author(s):

M. Haghshenas ◽

V. Bhakhri ◽

R. Oviasuyi ◽

R.J. Klassen

Keyword(s):

Strain Rate ◽

Effect Of Temperature ◽

Image Position

Abstract

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Preparation of superhydrophobic and superoleophobic Al–Mg alloy surface via simple, environmentally friendly method

Journal of Materials Research ◽

10.1557/jmr.2018.303 ◽

2018 ◽

Vol 33 (22) ◽

pp. 3818-3826 ◽

Cited By ~ 2

Author(s):

Ning Ma ◽

Yang Chen ◽

Shuguo Zhao ◽

Jingchun Li ◽

Baofeng Shan ◽

...

Keyword(s):

Environmentally Friendly ◽

Mg Alloy ◽

Alloy Surface ◽

Image Position ◽

Environmentally Friendly Method

Abstract

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Erebus Glacier Tongue, Mcmurdo Sound, Antarctica

Journal of Glaciology ◽

10.1017/s0022143000023340 ◽

1974 ◽

Vol 13 (67) ◽

pp. 27-35 ◽

Cited By ~ 39

Author(s):

G. Holdsworth

Keyword(s):

Shear Stress ◽

Strain Rate ◽

Shear Strain ◽

Longitudinal Strain ◽

Strain Rates ◽

Shear Strain Rate ◽

Mcmurdo Sound ◽

Glacier Tongue ◽

The Past ◽

Image Position

Examination of the past and present behaviour of the Erebus Glacier tongue over the last 60 years indicates that a major calving from the tongue appears to be imminent. Calculations of the regime of the tongue indicate that bottom melt rates may exceed 1 m a−1. By successive mapping of the ice tongue between the years 1947 and 1970, longitudinal strain-rates were determined using the change in distance between a set of 15 teeth, which are a prominent marginal feature of the tongue. Assuming a flow law for ice of the form where τ is the effective shear stress and is the effective shear strain-rate, values of the exponent n = 3 and B = 1 × 108 N m−2 are determined. These are in fair agreement with published values.

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Rheology of till beneath Storglaciären, Sweden

Journal of Glaciology ◽

10.3189/s0022143000002938 ◽

1997 ◽

Vol 43 (143) ◽

pp. 172-179 ◽

Cited By ~ 6

Author(s):

Roger LeB. Hooke ◽

Brian Hanson ◽

Neal R. Iverson ◽

Peter Jansson ◽

Urs H. Fischer

Keyword(s):

Strain Rate ◽

Water Pressure ◽

Force Balance ◽

Surface Velocity ◽

Shear Strain Rate ◽

Effective Pressure ◽

Frictional Material ◽

Image Position ◽

Gain Access

AbstractIn order to study, in situ, the rheology of a deforming subglacial till, various instruments were emplaced in till beneath Storglaciären, Sweden. Boreholes were used to gain access to the till beneath about 100 m of ice. Tiltmeters provided an estimate of the shear strain rate in the till. Two other instruments yielded measures of till strength. In addition, water pressures were recorded in boreholes and in the till, a computer-controlled distance meter provided an effectively continuous record of the surface velocity and data from frequent surveys of a stake network were used to estimate the mean basal drag, based on a force-balance calculation.Tilt rates varied directly with effective pressure, so decreases in water pressure apparently increased the coupling between the glacier and the bed. Surface speed was either out of phase with tilt or varied independently of tilt. Thus, increases in speed were apparently a consequence either of longitudinal coupling or of reduced coupling between the glacier and the bed; they were not a result of till deformation! Till strength varied directly with effective pressure, which is consistent with it being a Mohr – Coulomb, or frictional material. The devices measuring till strength are presumed to have been pulled through the till at a speed that varied in phase with the surface speed but till strength did not vary systematically with surface speed. This implies that the residual strength of the till is insensitive to strain rate. Thus, the appropriate constitutive equation for till rheology may be of the form:where k is a constant. This is consistent with experimental data reported in the geotechnical literature.

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