Analysis of Dendritic Primary Al Grain Ripening and Solid Fraction Measurement in A356 Alloy Semi-Solid Slurry Using Segregation Sensitive Reagent

2012 ◽  
pp. 1425-1430
Author(s):  
Li Gao ◽  
Yohei Harada ◽  
Shinji Kumai
Keyword(s):  
Solid Fraction ◽  
A356 Alloy ◽  
Semi Solid ◽  
Fraction Measurement

Modeling of Semi-Solid A356 Alloy under Upsetting Process

2006 ◽  
Vol 116-117 ◽  
pp. 622-625
Author(s):  
M. Shakiba ◽  
Hossein Aashuri
Keyword(s):  
Solid Fraction ◽  
Yield Criterion ◽  
Flow Behavior ◽  
A356 Alloy ◽  
Two Phase ◽  
Thermomechanical Process ◽  
Modeling Process ◽  
High Solid Fraction ◽  
Flow Through ◽  
Semi Solid

The flow behavior of a semi-solid A356 alloy at high solid fraction was studied. The mushy zone was considered as an effective two-phase, so that the solid continuum can be compressible porous media, and the liquid phase interaction with the solid skeleton was of Darcy type. The semi-solid flow through the upsetting test was modeled in ABAQUS finite element method software. The Gurson yield criterion has been developed for the modeling process of the flow behavior of solid porous medium. Specimens were globulized by a thermomechanical process and then were tested for various percentages of upsetting. The distribution of solid fraction along the radius of the specimens at different height reduction showed a good correlation with model prediction.

Modeling of the Semi-Solid Material Behavior and Analysis of Micro-/Mesoscale Feature Forming

2006 ◽  
Vol 129 (2) ◽  
pp. 237-245 ◽  
Author(s):  
Gap-Yong Kim ◽  
Muammer Koç ◽  
Rhet Mayor ◽  
Jun Ni
Keyword(s):  
Solid Fraction ◽  
A356 Alloy ◽  
Structural Evolution ◽  
Solid Material ◽  
Material Behavior ◽  
Flow Rule ◽  
Stress Model ◽  
Forming Process ◽  
Mesoscale Feature ◽  
Semi Solid

One of the major challenges in simulation of semi-solid forming is characterizing the complex behavior of a material that consists of both solid and liquid phases. In this study, a material model for an A356 alloy in a semi-solid state has been developed for high solid fractions (>0.6) and implemented into a finite element simulation tool to investigate the micro-/mesoscale feature formation during the forming process. Compared to previous stress models, which are limited to expressing the stress dependency on only the strain rate and the temperature (or the solid fraction), the proposed stress model adds the capability of describing the semi-solid material behavior in terms of strain and structural evolution. The proposed stress model was able to explain the strain-softening behavior of the semi-solid material. Furthermore, a simulation model that includes the yield function, the flow rule, and the stress model has been developed and utilized to investigate the effects of various process parameters, including analysis type (isothermal vs nonisothermal), punch velocity, initial solid fraction, and workpiece shape (“flat” versus “tall”) on the micro-/mesofeature formation process.

Prediction of Phase Segregation During Mold Filling of Semi-Solid Slurries

1999 ◽  
Author(s):  
Mahmut D. Mat ◽  
Olusegun J. Ilegbusi
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Solid Fraction ◽  
Transfer Rate ◽  
Phase Segregation ◽  
Mold Filling ◽  
Semisolid Slurry ◽  
Processing Parameter ◽  
Inlet Velocity ◽  
Semi Solid

Abstract Phase segregation during the mold filling of semisolid slurry (Sn-15%Pb) is numerically investigated under non-isothermal conditions. The effects of operating parameters on the phase segregation including inlet velocity, initial solid fraction, heat transfer rate, mold geometry are considered. The semi-solid slurry is considered a non-Newtonian fluid below a critical solid fraction (fcr) and a viscoplastic medium saturated with liquid phase above the critical solid fraction. A group of particles are introduced at the mold inlet and phase segregation is studied by following the trajectories of these particles. The sharp property change at the slurry air interface is resolved with Van Leer numerical method. It is found that phase segregation is significantly affected by processing parameter. The segregation decreases with high inlet velocity, low heat transfer rate from the mold wall and cylindrical mold geometry.

A Control of Microstructure of A356 Alloy by Sequential Semi-Solid Process

2008 ◽  
pp. 569-573
Author(s):  
Sung Chul Lim ◽  
Hai Joong Lee ◽  
Jang Won Kang ◽  
Sang Kil Lee ◽  
Kyung Hoon Kim ◽  
...  
Keyword(s):  
A356 Alloy ◽  
Semi Solid

Using ProCAST to Study the Effects of SEED Process Parameters on the Radial Temperature Distribution in Semi-Solid Slugs

2020 ◽  
Vol 993 ◽  
pp. 1004-1010
Author(s):  
Min Luo ◽  
Da Quan Li ◽  
Wen Ying Qu ◽  
Stephen P. Midson ◽  
Qiang Zhu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Transfer Coefficient ◽  
Solid Fraction ◽  
Process Parameters ◽  
Radial Temperature ◽  
Fraction Distribution ◽  
Semi Solid ◽  
The Heat Transfer Coefficient

The SEED (Swirled Enthalpy Equilibrium Device) process was used to produce semi-solid slurries. One of the factors that controls whether or not a slug can be used to produce high quality castings is the solid fraction distribution within the slug, and the solid fraction distribution is strongly dependent upon the temperature distribution. In this study, a model has been developed using ProCAST to investigate the relationship between process parameters and the temperature distribution within slugs. The parameters examined included the heat transfer coefficient between the crucible and slug, the heat transfer coefficient between the crucible and air, the slug diameter, and the initial melt temperature (pouring temperature). It was found that the most important parameters controlling the temperature distribution within slugs were the crucible size and the heat transfer coefficient between crucible and air. Adjustment of other parameters had little influence on the temperature distribution. Processing parameters will be discussed in order to allow the SEED process to be used for the production of large diameter slugs (>100 mm), and for narrow freezing range (0.3<fs<0.5, fs is fraction solid) alloys such as 6063.

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