Apparent Viscosity and Rheological Behavior of Aluminum-Alloy Slurry Containing Nano-Sized SiC Particles

2019 ◽  
Vol 285 ◽  
pp. 391-397
Author(s):  
Kang Lu ◽  
Shu Sen Wu ◽  
Shu Lin Lü ◽  
Chong Lin
Keyword(s):  
Aluminum Alloy ◽  
Rheological Behavior ◽  
Apparent Viscosity ◽  
Mass Fraction ◽  
Matrix Alloy ◽  
Rotating Cylinder ◽  
Viscous Force ◽  
Semi Solid ◽  
The Relationship ◽  
Cylinder Viscometer

The apparent viscosity and rheological behavior of nanoSiCP/Al-5Cu composites were studied by using a high temperature coaxial rotating cylinder viscometer. The results show that mass fraction of nanoSiCP is an important factor for apparent viscosity of the nanoSiCP/Al-5Cu composites, and there is a great enhancement of apparent viscosity of the slurry with the increase of nanoSiCp content. It can attribute to the viscous force between nanoSiCp and matrix alloy melt above the liquidus. The increased amplitude of apparent viscosity in semi-solid state is far less than those in liquid state with the increase of mass fraction of nanoSiCp. The apparent viscosities of the composites reinforced with 0.5%, 1%, 1.5% and 2% nanoSiCp at 700°C were 24.78%, 95.25%, 160.29% and 228.62% higher than that of Al-5Cu alloy, respectively. Besides, the rheological model of nanoSiCP/Al-5Cu composites was established based on the fitting curve, which can precisely describe the relationship between the apparent viscosity of nanocomposites slurry and nanoSiCp mass fraction.

Influence of Morphology on the Rheological Behavior of Semi-Solid A356 Aluminum Alloy

2006 ◽  
Vol 116-117 ◽  
pp. 601-605
Author(s):  
Heng Hua Zhang ◽  
Xian Nian Zhang ◽  
Guang Jie Shao ◽  
Luo Ping Xu ◽  
Yi Tao Yang ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Solid State ◽  
Rheological Behavior ◽  
Apparent Viscosity ◽  
Flow Behavior ◽  
A356 Alloy ◽  
Solid Alloy ◽  
A356 Aluminum Alloy ◽  
A356 Aluminum ◽  
Semi Solid

The morphology of semi-solid alloy is one of the key influence factors on the rheological behavior of slurry during die filling and the mechanical properties of formed parts. However, it is difficult to study such effect due to hard controlling of morphology in semi-solid state. In this paper, a self-developed Searle-type viscometer was used to determine the rheological behavior of A356 aluminum alloy in different morphology, which was refined with the salts mixture of K2TiF6 and KBF4. The results indicated that the flow behavior of refined A356 alloy in the semi-solid state possesses obviously thixotropic behavior under isothermal shearing condition with less time to reach steady state and lower steady apparent viscosity as compared to that of the A356 alloy. During continuous cooling at a constant shearing rate, the apparent viscosity of refined A356 slurry in the same solid fraction decreased with the content of Ti. It is shown from quantitative image analysis that the primary α-Al grain in the refined alloy evolves from dendrites to rosettes or sphericitys, and then tends to be rounder and finer in higher Ti content. The mechanism of the influence of morphology on rheological behavior was also discussed in this paper.

Influence of Morphology on the Rheological Behavior of Semi-Solid A356 Aluminum Alloy

2006 ◽  
pp. 601-605
Author(s):  
Heng Hua Zhang ◽  
Xian Nian Zhang ◽  
Guang Jie Shao ◽  
Luo Ping Xu ◽  
Yi Tao Yang ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Rheological Behavior ◽  
A356 Aluminum Alloy ◽  
A356 Aluminum ◽  
Semi Solid

Microstructure and Mechanical Properties of Semi-Solid Die-Cast A356 Aluminum Alloy

2016 ◽  
Vol 877 ◽  
pp. 39-44
Author(s):  
Si Min Lei ◽  
Li Gao ◽  
Yohei Harada ◽  
Shinji Kumai
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
A356 Aluminum Alloy ◽  
Microstructure And Mechanical Properties ◽  
Die Cast ◽  
Microstructural Evaluation ◽  
Cast Machine ◽  
A356 Aluminum ◽  
Semi Solid ◽  
The Relationship

The present work deals with the relationship between microstructure and mechanical properties of A356 aluminum alloy which was produced via thixocasting process under different casting conditions. Feedstock billets were heated to a target temperature to obtain a semi-solid slurry with the required solid fraction. Some billets were heated to a fully-melted condition. In order to obtain fine and spheroidized Al grains, some billets for the partially melting were compressed axially by 33% at a room temperature before heating. The completely-melted and partially-melted slurries were die-cast by using a die-cast machine, and hour glass-shaped rod-type tensile specimens and small-size plate-type tensile specimens were obtained. Small cubic specimens were also collected from the die-cast products for microstructural evaluation. They were polished, and etched by Weck’s reagent. The partially-melted specimen which was compressed before heating shows the spherical Al grains. But the grain of the strain-free partially-melted specimen exhibited complicated morphology. The fully-melted specimen shows the fine and dendrite structure.

The Influence of Strontium on Microstructural and Rheological Behavior of the Semi-solid A380 Aluminum Alloy

2020 ◽  
Vol 51 (12) ◽  
pp. 6421-6431
Author(s):  
João Paulo Gabre Ferreira ◽  
Luciano Augusto Lourençato ◽  
Angel Sánchez Roca ◽  
Hipolito Domingo Carvajal Fals
Keyword(s):  
Aluminum Alloy ◽  
Rheological Behavior ◽  
Semi Solid

Numerical Simulation of Mould Filling in Rheocasting Process of Semisolid A356 Aluminum Alloy

2008 ◽  
Vol 141-143 ◽  
pp. 599-604
Author(s):  
Yue Long Bai ◽  
Jun Xu ◽  
Wei Min Mao ◽  
Zhi Feng Zhang ◽  
Hong Xu
Keyword(s):  
Aluminum Alloy ◽  
Apparent Viscosity ◽  
Viscosity Model ◽  
Semisolid Slurry ◽  
A356 Aluminum Alloy ◽  
Mould Filling ◽  
Forming Temperature ◽  
Simulation Results ◽  
A356 Aluminum ◽  
Semi Solid

The apparent viscosity model of the semi-solid A356 aluminum alloy, based on fitting of experimental data obtained by the Couette type viscometer, was developed in the paper. The commercial package CastSoft6.0 coupled with the model was used to simulate the mould filling of the semi-solid A356 aluminum alloy in the key-shaped component with iron cores. The simulation results showed that the position of the iron cores has an important effect on the filling of the semisolid slurry, and it is easy to obtain the completely filled key-shaped component when the iron cores were near to the inlet. The filling tests verified that the simulation results have good agreement with the experimental results. The fitting results indicated that the developed apparent viscosity model is practical and feasible and it can be used to simulate the mould filling process of the semisolid A356 aluminum alloy slurry. Also the parameters were optimized and the optimum parameters are as follows: the inject pressure is more than 15MPa, the inlet velocity is more than 1.73m/s and the forming temperature is over 585 °C.

Investigation of the Relationships between Billet Reheating and Semi-Solid Die-Casting

2010 ◽  
Vol 97-101 ◽  
pp. 306-310 ◽  
Author(s):  
Xiang Lin Yin ◽  
Yi Tao Yang ◽  
Yu Peng Shao ◽  
Guang Jie Shao
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Aluminum Alloy ◽  
Die Casting ◽  
Surface Hardness ◽  
A356 Aluminum Alloy ◽  
Final Temperature ◽  
A356 Aluminum ◽  
Semi Solid ◽  
The Relationship

The non-dendritic of A356 aluminum alloy billet was reheated to meet the requirements of the semi-solid microstructure by three different kinds of power, achieving the same final temperature of 863K. Subsequently, under the same conditions of die-casting (thixoforming), the microstructure was observed, surface hardness and tensile properties were measured. Afterwards, quantitative analysis was made for the microstructure of the reheated semi-solid of billet and the thixoforming parts. The results showed that the larger induction reheating power of the billet, the smaller the grain size of its microstructure and the higher surface hardness and the better mechanical properties of its thixoforming sample. Finally, through studying on the relationship between the microstructure of the semi-solid billet of A356 aluminum alloy and the mechanical properties of the thixoforming sample, we primarily achieved the reverse design of microstructure.

Characterization of the Microstructure and Rheological Behavior of Al-4wt%Si-2.5wt%Cu Alloy Produced by Direct Chill Casting and Electromagnetic Stirring

2012 ◽  
Vol 192-193 ◽  
pp. 142-148 ◽  
Author(s):  
Luis Vanderlei Torres ◽  
Eugênio José Zoqui
Keyword(s):  
Rheological Behavior ◽  
Apparent Viscosity ◽  
Primary Particle ◽  
Raw Materials ◽  
Morphological Evolution ◽  
Raw Material ◽  
Electromagnetic Stirring ◽  
Cu Alloy ◽  
Semi Solid

This work involved an evaluation of a Al-4wt%Si-2.5wtCu alloy to be used as raw materials in the thixoforming process. The alloy was produced by direct casting under electromagnetic stirring to obtain ingots of 250 mm length and 30 mm diameter. The alloy was analyzed to determine their morphology and rheological behavior in the semi-solid range. The tests included characterization of the microstructural evolution by subjecting them to re-heating treatment in two conditions of solid fractions, 45% and 60%, for 0, 30, 90 and 210 s. A compression testing device designed specifically to evaluate semi-solid materials was used to determine the rheological behavior, and the tests were performed at the same heating rate and hold times to determine the apparent viscosity. The use of electromagnetic stirring to produce the raw material was effective in producing alloy with very small grain/primary particle sizes (80 up to 120 µm). Based on the morphological evolution in the semi-solid state, the alloy showed only minor variations in grain/primary particle size and surface factor (SF) as a function of the different globularization heat treatment times, suggesting that all these alloys are suitable for production. The Al-4.0wt%Si-2.5wt%Cu alloy with 45% solid fraction presented apparent viscosity about 1.5 x106 Pa.s.

Pressure-driven mold filling model of aluminum alloy melt/semi-solid slurry based on rheological behavior

2020 ◽  
Vol 39 ◽  
pp. 14-21 ◽  
Author(s):  
Zhen Ma ◽  
Huarui Zhang ◽  
Wei Song ◽  
Xiaoyan Wu ◽  
Lina Jia ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Rheological Behavior ◽  
Mold Filling ◽  
Semi Solid ◽  
Pressure Driven

Rheological Behavior and Fluidity of Semi-Solid SiCp/A357 Composites with Different SiC Addition Levels

2016 ◽  
Vol 256 ◽  
pp. 126-132 ◽  
Author(s):  
Zhen Lin Zhang ◽  
Zhi Feng Zhang ◽  
Jun Xu ◽  
Wei Min Mao
Keyword(s):  
Shear Rate ◽  
Solid Fraction ◽  
Rheological Behavior ◽  
Apparent Viscosity ◽  
Stir Casting ◽  
Sic Particles ◽  
Semi Solid ◽  
Test Casting ◽  
Good Agreement

The apparent viscosities of the semi-solid SiCp/A357 composites with 0vol.%, 10vol.% and 20vol.% SiC particles manufactured by stir casting were investigated using a Couette type viscometer, and the composite fluidity was examined with a test casting. The results showed that, the viscosities of the semi-solid SiCp/A357 composites decreased with an increase in shear rate, but increased with the increasing of solid fraction, and apparent viscosity of 10vol.% SiCp/A357 composite was the lower than that of 20vol.% SiCp/A357 composite at the same solid fraction; and the composite fluidity results were in a good agreement with the viscosity ones.

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