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.

Semi-Solid Forming of A356 Alloy by Rapid Slurry Forming Process

2012 ◽  
pp. 1441-1450
Author(s):  
S. Sharma ◽  
A. Sharma ◽  
S. Kumar
Keyword(s):  
A356 Alloy ◽  
Forming Process ◽  
Semi Solid

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.

Effect of Solid Fraction on Microstructure and Casting Faults of AZ91D Alloys in New Type Semi-Solid Injection Process

2006 ◽  
Vol 116-117 ◽  
pp. 441-444 ◽  
Author(s):  
Kenji Miwa ◽  
Rudi S. Rachmat ◽  
Takuya Tamura
Keyword(s):  
Solid Fraction ◽  
Testing Machine ◽  
Solid Particles ◽  
Casting Defects ◽  
Permanent Mold ◽  
Forming Process ◽  
Injection Process ◽  
Controlling System ◽  
New Type ◽  
Semi Solid

We have developed new type semi-solid injection process, that is, runner-less injection process. In order to investigate the effects of solid fraction on microstructure and casting defects of AZ91D in new type semi solid injection process, semi-solid forming testing machine which has the same system as a runner-less injection machine has been made on an experimental basis. Its temperature controlling system has been established to obtain the homogeneous solid-liquid coexisted state in its injection cylinder. AZ91D billets are injected into a permanent mold by this machine in the semi-solid state. A shearing in the part of nozzle of injection cylinder is the most important to reveal thixotropic property of alloy slurry in semi solid forming process by injection machine. So it needs controlling of solid fraction to affect thixotropic property. In order to decrease casting defects and hold homogeneous structure, solid fraction more over 50% is needed. But when the solid fraction increases more than 50%, primary solid particles grow coarser, and then controlling method is required to suppress coarsening. In the case of less than 50% of solid fraction, liquid part preferentially fills inside the permanent mold and alloy slurry continue to fill the mold behind alloy liquid. Then large casting defects form at the boundary of both flows.

Werkstückerwärmung für das Thixoforming*/Heating workpieces for Thixoforming - Using inductor as sensor for monitoring the heating process of semi-solid material

2017 ◽  
Vol 107 (05) ◽  
pp. 340-345
Author(s):  
J. Uphoff ◽  
A. Lechler ◽  
A. Prof. Verl
Keyword(s):  
Solid State ◽  
Solid Fraction ◽  
Material Properties ◽  
Solid Material ◽  
Heating Process ◽  
Inductive Heating ◽  
Inductor Coil ◽  
Specific Material ◽  
Semi Solid

Das Thixoforming nutzt bei der Formgebung besondere Materialeigenschaften zur Herstellung metallischer Bauteile. Die verwendeten Legierungen müssen dazu in den sogenannten teilflüssigen Bereich erwärmt werden. Das Einstellen des geforderten Fest-Flüssig-Verhältnisses stellt besondere Anforderungen an die Erwärmung. Betrachtet werden verschiedene Messverfahren, welche die Induktorspule bei der induktiven Erwärmung als Sensor nutzen.   Thixoforming uses specific material properties for shaping metal workpieces. For this purpose, the alloys need to be heated to the so-called semi-solid state. The adjustment of the desired semi-solid fraction imposes high requirements on the heating process. Various measurement principles, which use the inductor-coil as a sensor in inductive heating processes, are presented.

Effect of Plunger Speed and Solid Fraction on Automotive Component by Thixoforming Simulation

2020 ◽  
Vol 17 (2) ◽  
pp. 7942-7955
Author(s):  
M.R. Mohamad Kamal ◽  
N.F. Bazilah ◽  
N.F. M. Pzil ◽  
M.H. Idris ◽  
M.S. Salleh ◽  
...  
Keyword(s):  
Solid Fraction ◽  
Solidification Rate ◽  
Solid Content ◽  
Simulation Software ◽  
Forming Process ◽  
3D Cad ◽  
Alloy Az91d ◽  
Metal Forming Process ◽  
Thixotropic Behaviour ◽  
Semi Solid

Thixoforming is a promising metal forming process to produce near net-shape components with high casting quality. Thixoforming of metallic alloy utilizes the thixotropic behaviour of the material with near globular or globular microstructure in the semi-solid condition. The solid content is between 50% to 70% before forming. In this paper, the effect of plunger speed and a solid fraction on an alternator housing was investigated by advance casting simulation software. The 3D CAD model of the alternator housing was created using SolidWorks software and AnyCasting software is utilized for the simulation of the thixoforming parameter and magnesium alloy (AZ91D) is the material used. The simulation had been done by varying the plunger speed, temperature (solid fraction) of the material, and both Power Law and Bingham Viscosity model are used in the simulation to identify the defect prediction at the end. The simulation result shows that laminar filling in semi-solid slurry able to achieved by controlling the plunger speed and temperature. Slower speed and lower melt temperatures are preferable in thixoforming. Therefore, a solid fraction of the material, plunger speed, and solidification rate do influence the filling behaviour of the casting of semi-solid metal.

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