scholarly journals Triaxial Compression on Semi-solid Alloys

2021 ◽  
Author(s):  
Fatin N. Altuhafi ◽  
Catherine O’Sullivan ◽  
Peter Sammonds ◽  
Te-Cheng Su ◽  
Christopher M. Gourlay
Keyword(s):  
Flow Stress ◽  
Soil Mechanics ◽  
Triaxial Compression ◽  
Effective Pressure ◽  
Volume Data ◽  
Similarities And Differences ◽  
Dependent Flow ◽  
Semi Solid ◽  
Solid Alloys ◽  
Volumetric Response

AbstractMulti-axial compression of the mushy zone occurs in various pressurized casting processes. Here, we present a drained triaxial compression apparatus for semi-solid alloys that allow liquid to be drawn into or expelled from the sample in response to isotropic or triaxial compression. The rig is used to measure the pressure-dependent flow stress and volumetric response during isothermal triaxial compression of globular semi-solid Al-15 wt pct Cu at 70 to 85 vol pct solid. Analysis of the stress paths and the stress–volume data show that the combination of the solid fraction and mean effective pressure determines whether the material undergoes shear-induced dilation or contraction. The results are compared with the critical state soil mechanics (CSSM) framework and the similarities and differences in behavior between equiaxed semi-solid alloys and soils are discussed.

Rheology of Semi-Solid Steel Alloys at Temperatures up to 1500°C

2006 ◽  
Vol 116-117 ◽  
pp. 606-609 ◽  
Author(s):  
Michael Modigell ◽  
Lars Pape ◽  
Horst R. Maier
Keyword(s):  
Flow Behavior ◽  
Measuring System ◽  
Model Parameters ◽  
Flow Properties ◽  
Steel Alloys ◽  
Ceramic Components ◽  
Dependent Flow ◽  
Couette Rheometer ◽  
Semi Solid ◽  
Solid Alloys

The investigation of the flow behavior of semi-solid steel alloys poses a great challenge by reason of high operation temperatures and the need of ceramic components for the measuring system. A high-temperature Couette rheometer has been developed to analyze flow properties of semi-solid alloys up to temperatures of 1500°C. In the present work the alloy under investigation is X210CrW12. Differently performed experiments clearly show its shear-thinning and time-dependent flow properties with a yield stress. This flow behavior is modeled using a Herschel-Bulkley approach where the experimental results achieved serve to identify model parameters.

Flow Stress, Yield Criterion and Constitutive Equation of Mushy/Semi -Solid Alloys

CIRP Annals ◽  
2001 ◽  
Vol 50 (1) ◽  
pp. 157-160 ◽  
Author(s):  
M. KIUCHI ◽  
J. YANAGIMOTO ◽  
H. YOKOBAYASHI
Keyword(s):  
Flow Stress ◽  
Constitutive Equation ◽  
Yield Criterion ◽  
Semi Solid ◽  
Solid Alloys

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

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.

scholarly journals A New Process to Manufacture Semi-solid Alloys.

1995 ◽  
Vol 35 (6) ◽  
pp. 790-797 ◽  
Author(s):  
Manabu Kiuchi ◽  
Sumio Sugiyama
Keyword(s):  
New Process ◽  
Semi Solid ◽  
Solid Alloys

scholarly journals Influence of Thermal Aging Parameters on the Characteristics of Aluminum Semi-Solid Alloys

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 746 ◽  
Author(s):  
Khaled Ragab ◽  
Mohamed Bouazara ◽  
Xiao Chen
Keyword(s):  
Electron Microscopy ◽  
Aluminum Alloys ◽  
Thermal Aging ◽  
Aging Treatment ◽  
Load Variations ◽  
Transmission Electron ◽  
Semisolid Alloys ◽  
Automotive Parts ◽  
Semi Solid ◽  
Solid Alloys

The current study aimed at analyzing the response of semisolid A357 aluminum alloys to unconventional thermal treatment cycles of T4/T6/T7 conditions. The mechanical, electrical, and microstructural characterizations of such semisolid alloys were investigated. The microstructure evolutions of Fe-intermetallic phases and strengthening precipitates were characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The mechanical failure of such semi solid A357 aluminum alloys, used for suspension automotive parts, is mostly related to cracking issues which start from the surface due to hardness problems and propagate due to severe load variations. For these reasons, the multiple thermal aging cycles, in this study, are applied to enhance the mechanical properties and to have compromised values compared to those obtained by standard thermal treatments. The results obtained in this work indicate that the heat treatment of this alloy can be optimized. The results showed that the optimum characteristics of A357 semisolid alloys were obtained by applying thermal under-aging cycle, interrupted thermal aging cycles and a T7/T6 two steps aging treatment condition. The electrical conductivity and electron microscopy were applied in this study to analyze the characteristics of hardening phases formed due to different aging cycles applied to the alloys investigated.

Flow Behaviour of M2 Steel Alloy during Semi Solid Isothermal Rapid Compression

2012 ◽  
Vol 192-193 ◽  
pp. 311-316
Author(s):  
Farzad Hosseini Yekta ◽  
S.A. Sadough ◽  
Vahid Pouyafar ◽  
Amin Jabbari
Keyword(s):  
Flow Stress ◽  
Tool Steel ◽  
Constant Strain Rate ◽  
Special Kind ◽  
Holding Time ◽  
Plastic Behavior ◽  
Steel Alloy ◽  
Rapid Compression ◽  
Ram Speed ◽  
Semi Solid

The key to all semisolid processes is spherical and non-dendritic particles suspended in a liquid matrix. This special kind of microstructure causes the semisolid material to behave like a non-Newtonian fluid dependent on time and shear rate. Semi solid metal processing gives less shrinkage and porosity, non-macro segregation, lower flow stress, good formability and increased die life compared with conventional production methods. Therefore, semi solid processing introduces a good option for massive forming of high temperature alloys. Here, by partial remelting of M2 tool steel alloy under rapid compression test, deformation mechanism of steel alloy and its correlation to rheological properties were investigated. Flow stress for M2 tool steel alloy corresponding to solid fraction above 55% derived at constant strain rate and holding time. In order to investigate the parameter involved in this process, in the second stage of experiments the ram speed and holding time are variable. The analysis of the derived curves shows that the semisolid slurries exhibit a pseudo plastic behavior dependent on stain rate and temperature. The classical power law model used to describe the rheological and thixotropic dependence.

scholarly journals Relation between the Friction Angle of Sand at Triaxial Compression and Triaxial Extension and Plane Strain Conditions

Geosciences ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 29 ◽  
Author(s):  
Zenon Szypcio
Keyword(s):  
Plane Strain ◽  
Soil Mechanics ◽  
Triaxial Compression ◽  
Deformation Mode ◽  
Friction Angle ◽  
Failure Criteria ◽  
Compression Tests ◽  
Laboratory Test Results ◽  
Experimental Findings ◽  
Triaxial Extension

The strength of sand is usually characterized by the maximum value of the secant friction angle. The friction angle is a function of deformation mode, density, and stress level and is strongly correlated with dilatancy at failure. Most often, the friction angle is evaluated from results of conventional compression tests, and correlation between the friction angle of sand at triaxial compression and triaxial extension and plane strain conditions is a vital problem of soil mechanics. These correlations can be obtained from laboratory test results. The failure criteria for sand presented in literature also give the possibility of finding correlations between friction angles for different deformation modes. The general stress-dilatancy relationship obtained from the frictional state concept, with some additional assumptions, gives the possibility of finding theoretical relationships between the friction angle of sand at triaxial compression and triaxial extension and plane strain conditions. The theoretically obtained relationships presented in the paper are fully consistent with theoretical and experimental findings of soil mechanics.

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