Effect of pouring temperature on fractal dimension of primary phase morphology in semi-solid A356 alloy

2009 ◽  
Vol 19 (5) ◽  
pp. 1098-1103 ◽  
Author(s):  
Zheng LIU ◽  
Wei-min MAO ◽  
Xiao-mei LIU
Keyword(s):  
Fractal Dimension ◽  
A356 Alloy ◽  
Primary Phase ◽  
Phase Morphology ◽  
Pouring Temperature ◽  
Semi Solid

Study on Fractal Characteristics of Primary Phase Morphology in Semi-Solid A356 Alloy

2010 ◽  
Vol 139-141 ◽  
pp. 653-656
Author(s):  
Zheng Liu ◽  
Xiao Mei Liu
Keyword(s):  
Fractal Dimension ◽  
A356 Alloy ◽  
Fractal Dimensions ◽  
Primary Phase ◽  
Phase Morphology ◽  
Fractal Characteristic ◽  
Box Counting ◽  
Compound Process ◽  
Fractal Characteristics ◽  
Semi Solid

Semi-solid A356 slurry was prepared by compound process, and the fractal characteristic of primary phase morphology was researched. The fractal dimensions of primary phase morphology in semi-solid A356 alloy were calculated by the calculating program written to calculate the fractal dimensions of box-counting in the imagine of morphology of semi-solid primary phase in A356 alloy. The results indicated that the primary phase morphology in semi-solid A356 prepared by compound process is characterized by fractal dimension, and the primary phase morphology prepared by the different technology parameters had different fractal dimensions. The primary phase morphology at the different position of ingot had the different fractal dimensions, which reflected the effect of solidified conditions at different position in the same ingot on the morphology of semi-solid primary phase

Characterization on Primary Phase Morphology of Semisolid A356 Alloy during Isothermal Holding with Fractal

2012 ◽  
Vol 531-532 ◽  
pp. 67-72 ◽  
Author(s):  
Zheng Liu ◽  
Xiao Mei Liu
Keyword(s):  
Fractal Dimension ◽  
Fractal Theory ◽  
Isothermal Holding ◽  
A356 Alloy ◽  
Primary Phase ◽  
Phase Morphology ◽  
Processing Conditions ◽  
Alloy Solidification ◽  
Fractal Character ◽  
Holding Temperature

Semisolid A356 alloy was prepared by low superheat pouring, and evolution of primary phase morphology in semisolid A356 alloy during isothermal holding was characterized by fractal theory. The results indicated that the primary phase morphology in the alloy had fractal character, and the evolution of the primary phase morphology in the alloy could be characterized by fractal dimension. The primary phase morphology at the different isothermal holding temperature and holding time had the different fractal dimension, which meant the effect of processing conditions on the morphology in the alloy. Solidification of the alloy was a course of change in fractal dimension.

Fractal Characteristics of Primary Phase Morphology in Semisolid A356 Alloy

2012 ◽  
Vol 535-537 ◽  
pp. 936-940
Author(s):  
Zheng Liu ◽  
Xiao Mei Liu
Keyword(s):  
Fractal Dimension ◽  
A356 Alloy ◽  
Fractal Dimensions ◽  
Processing Parameters ◽  
Primary Phase ◽  
Phase Morphology ◽  
Box Counting ◽  
Magnetic Stirring ◽  
Fractal Characteristics ◽  
Electro Magnetic

Semisolid A356 alloy was prepared by low superheat pouring and slightly electro- magnetic stirring(LSPSES). The fractal dimensions of primary phase morphology in semisolid A356 alloy were researched by the calculating program written to calculate the fractal dimensions of box-counting in the image of primary phase morphology in semisolid A356 alloy. The results indicated that the primary phase morphology in the alloy was characterized by fractal dimension, and the morphology obtained by the different processing parameters had the different fractal dimension. The morphology at the different position of ingot had the different fractal dimensions, which reflected the effect of solidified conditions at different position in the same ingot on the morphology in the alloy. Solidification of the alloy was a course of change in fractal dimension.

scholarly journals Microstructure Evolution and Solidification Behavior of a Novel Semi-Solid Alloy Slurry Prepared by Vibrating Contraction Inclined Plate

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1810
Author(s):  
Yan Liu ◽  
Minqiang Gao ◽  
Ying Fu ◽  
Weirong Li ◽  
Pan Yang ◽  
...  
Keyword(s):  
Inclination Angle ◽  
Microstructure Evolution ◽  
Vibration Frequency ◽  
A356 Alloy ◽  
Good Mechanical Property ◽  
Solid Alloy ◽  
Solidification Behavior ◽  
Inclined Plate ◽  
Pouring Temperature ◽  
Semi Solid

In this work, based on the A356 alloy, a novel Al–Si–Mg–Cu–Fe–Sr alloy with good mechanical property and high thermal conductivity was developed. The semi-solid slurry of the alloy was prepared via the vibrating contraction inclined plate. The microstructure evolution and solidification behavior of the alloy were investigated. The results demonstrated that, compared with the A356 alloy, the enhanced property of the Al–Si–Mg–Cu–Fe–Sr alloy was associated with the size of primary α-Al grains and morphology of eutectic Si phases. In addition, the preparation process parameters of semi-solid slurries, including the pouring temperature, inclination angle, and vibration frequency, had a crucial effect on the size and morphology of primary α-Al grains. The optimized pouring temperature, inclination angle, and vibration frequency were 670 °C, 45°, and 60 Hz, respectively. In this condition, for the primary α-Al grains, a minimum grain diameter of 64.31 µm and a maximum shape factor of 0.80 were obtained. This work provides a reference for the application of the alloy with high performance in the field of automobile and communication.

Effect of Serpentine Channel Pouring Process on the Microstructure of Semi-Solid 6061 Aluminum Alloy Slurry

2022 ◽  
Vol 327 ◽  
pp. 255-262
Author(s):  
Nai Yong Li ◽  
Wei Min Mao ◽  
Xiao Xin Geng ◽  
Peng Yu Yan
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Shape Factor ◽  
Primary Phase ◽  
High Quality ◽  
Pouring Temperature ◽  
6061 Aluminum Alloy ◽  
Serpentine Channel ◽  
Channel Surface ◽  
Semi Solid

The semi-solid slurry of 6061 aluminum alloy was prepared by the serpentine channel pouring process. The influence of graphite serpentine channel and copper serpentine channel on the slurry was comparative analyzed. The effect of pouring temperature on the slurry microstructure was also investigated. The results indicate that both copper and graphite serpentine channel can be used to prepare semi-solid slurry with spherical primary grains. Compared with a permanent casting, the microstructure of the semi-solid slurry was significantly improved and refined. With the increase of pouring temperature, the average equivalent grain diameter of the primary phase grains in the semi-solid slurry increases gradually, but the shape factor decreases gradually. When the pouring temperature increased from 675 °C to 690 °C, a high quality semi-solid slurry can be obtained. Comparing the two kinds of serpentine channel, it is found that the copper serpentine channel can make the primary grains finer, and the average equivalent grain size was 63 μm. However, the solidified shell near the inner graphite serpentine channel surface was thinner than that of the copper serpentine channel. In conclusion, the graphite serpentine channel is more suitable for preparing semi-solid 6061 aluminum alloy slurry.

A New Method of Characterization on Microstructure of Casting Alloy

2011 ◽  
Vol 211-212 ◽  
pp. 122-126
Author(s):  
Zheng Liu ◽  
Xiao Mei Liu
Keyword(s):  
Fractal Dimension ◽  
Fractal Structure ◽  
A356 Alloy ◽  
Fractal Dimensions ◽  
Primary Phase ◽  
New Method ◽  
Casting Alloy ◽  
Microstructural Characteristics ◽  
Low Superheat

Microstructural characteristics of A356 alloy prepared by low superheat pouring were researched, and the fractal dimensions of morphology of primary phase in the alloy was calculated. The results indicated that morphology of primary phase in A356 alloy belonged to fractal structure, and the microstructural characteristics in the alloy can be characterized by fractal dimension. There were the different fractal dimensions for the morphology of primary phase prepared by the different process.

Continuous Fabrication of Sound Semi-Solid Slurry for Rheoforming

2006 ◽  
Vol 116-117 ◽  
pp. 425-428 ◽  
Author(s):  
Hong Min Guo ◽  
Xiang Jie Yang
Keyword(s):  
High Efficiency ◽  
Primary Phase ◽  
Process Window ◽  
Equivalent Diameter ◽  
Forming Process ◽  
Pouring Temperature ◽  
Initial Stage ◽  
Semi Solid ◽  
Continuous Fabrication ◽  
Low Superheat

An alternative method has been proposed for the continuous and sample production of SSM slurry for the rheo-forming process. The process named “Low Superheat Pouring with a Shear Field (LSPSF)” dose not use the conventional stirring process, instead, it uses solidification conditions to control nucleation, nuclei survival and grain growth by means of low superheat pouring, vigorous mixing and rapid cooling during the initial stage of solidification combined with thereafter a much slower cooling. The method has been applied to A356, 201 and A380 Al-alloys. The primary phases present in average equivalent diameter of 40-70μm, 35-50μm and 50-70μm for A356, 201 and A380, respectively. The morphology of primary phases is nearly spherical with shape factor of 0.78-0.86, 0.71-0.83 and 0.85-0.96 for A356, 201 and A380, respectively. For each of those alloys, there is no eutectic entrapped within the primary phase. The advantages of the LSPSF include process simplicity with high efficiency, easy incorporation into existing metal forming installation without infrastructure changes and a wide process window for pouring temperature.

Semi-Solid A356 Alloy Slurry Prepared by Slightly Electromagnetic Stirring with Ti-Based Refiner

2010 ◽  
Vol 152-153 ◽  
pp. 1745-1750
Author(s):  
Zheng Liu ◽  
Xiao Mei Liu ◽  
Wei Min Mao
Keyword(s):  
Grain Size ◽  
A356 Alloy ◽  
Particle Morphology ◽  
Primary Phase ◽  
Electromagnetic Stirring ◽  
Semi Solid

The semi-solid A356 alloy slurry is prepared by slightly electromagnetic stirring with Ti-based refiner. The effects of the refiner on the morphology and the grain size of the primary phase in the slurry are researched. The results indicate that the slurry with particle-like and rosette-like primary phases can be prepared by slightly electromagnetic stirring with the refiner. Compared with the A356 alloys without the refiner, the grain size and particle morphology of primary phase as well as the distribution of the grain with particle-like or rosette-like along radial in the ingot in A356 are markedly improved by the refiner.

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