A Compound Process Preparing Semi-Solid A356 Alloy Slurry

2010 ◽  
Vol 97-101 ◽  
pp. 1003-1007 ◽  
Author(s):  
Zheng Liu ◽  
Wei Min Mao

The semi-solid A356 alloy slurry is prepared by compound process, and the effect of the compound process on morphology and size of primary α-Al in A356 alloy is researched. The results indicate that the compound process remarkably affects the morphology and the size of primary α-Al. Primary α-Al with particle-like is distributed uniformly in A356 alloy, and there is no the transient area of change in structure morphology. Compared with the samples prepared by low superheat pouring and slightly electromagnetic stirring, the nucleation rate, morphology and grain size of primary α-Al in A356 alloy are markedly improved by the compound process. The mechanism of refining grain in the compound process is probed.

2010 ◽  
Vol 152-153 ◽  
pp. 1745-1750
Author(s):  
Zheng Liu ◽  
Xiao Mei Liu ◽  
Wei Min Mao

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.


2016 ◽  
Vol 877 ◽  
pp. 114-120
Author(s):  
Zheng Liu ◽  
Li Na Xu ◽  
Jia Yi Zhang ◽  
Guang Zhu Bai ◽  
Xiao Mei Liu

Based on the green and saving concept, a complex process preparing semisolid alloy slurry was developed, which was composed of the low superheat pouring and low frequency electromagnetic stirring. The semisolid A356-La slurry was prepared by the complex process, and the microstructure of the semisolid A356-La alloy was researched under the different preparing parameters in the complex process, such as the pouring temperature, electromagnetic stirring frequency, stirring time and micro-addition of La. The results indicated that it was feasible to reduce the addition of La and consumption of energy during the preparation of semisolid alloy slurry by optimizing the preparing parameters in the complex process. The suitable preparing parameters were obtained by the experiment, in which the pouring temperature was 630 °C, the frequency of electromagnetic stirring was 30 Hz, and the stirring time was 8 s. When semisolid A356 alloy slurry added 0.3 wt% La was prepared by the suitable preparing parameters in the complex process, the refining effects on microstructure in the semisolid A356-0.3La alloy was indistinguishable with that of the conventional addition amount of 0.6 wt% La in semisolid A356 alloy prepared by low superheat pouring.


2011 ◽  
Vol 322 ◽  
pp. 361-364
Author(s):  
Zheng Liu ◽  
Xiao Mei Liu ◽  
Yong Mei Hu

Semisolid A356 alloy, which is grain-refined by Pr, was prepared by low superheat pouring. The effects of grain-refined by Pr on the morphology and the grain size of the primary α-Al in semisolid A356 alloy are researched. The results indicate that semisolid A356 alloy with particle-like and rosette-like primary α-Al can be prepared by low superheat pouring from liquid A356 alloy grain-refined by Pr. The grain size and particle morphology of primary α-Al in A356 alloy are markedly improved by 0.3wt% Pr. The refining mechanism of Pr on the morphology and the grain size of the primary α-Al in semisolid A356 alloy were delved.


2012 ◽  
Vol 430-432 ◽  
pp. 886-889 ◽  
Author(s):  
Zheng Liu ◽  
Fu Yong Wang ◽  
Kai Cao ◽  
Hong Biao Xu ◽  
Mei Yan Huang

The semisolid A356 alloy slurry was prepared by low superheat pouring and slightly electromagnetic stirring (LSPSES). The effects of frequency conversion on the slurry were researched for energy-saving. The results indicated that it was feasible to prepare the slurry with particle primary phases by LSPSES. The application of frequency conversion technique into the preparation of the slurry by LSPSES was favorable to satisfying the requirements of rheo-forming and reducing the energy consumption.


2019 ◽  
Vol 285 ◽  
pp. 290-295
Author(s):  
Nora Nafari ◽  
Farnoush Yekani ◽  
Hossein Aashuri

A three phase electromagnetic stirrer was used to agitate aluminum A356 slurry and a dry and oxygen free argon gas was introduced in to the slurry by a porous graphite core at a same time. The prepared semi-solid slurry was then transferred into a metallic mold and was compacted by a drop weight. Results demonstrated a favorable increase in shape factor, decrease in aspect ratio and average diameter size at different intensities of stirring. The intensity of stirring was changed by altering the current passed through the magnetic coil and also bubbling intensity via the porous graphite diffuser. Different time intervals for electromagnetic stirring and gas induction were applied. Agitating the slurry for 90 Sec. separately by electromagnetic stirrer and GISS method, gave better results in terms of shape factor, decrease in average diameter of the globules and aspect ratio.


2011 ◽  
Vol 266 ◽  
pp. 84-88
Author(s):  
Wen Liu ◽  
Ji Qiang Li ◽  
Xu Ding

The influence of processing parameters on the semi-solid microstructure has been investigated in the course of semi-solid slurry preparation of A356 aluminum alloy by alternating electromagnetic stirring. The results show that compared with horizontal, vertical and spiral magnetic stirring method, alternating magnetic stirring could make eligible slurry with finer, more equiaxed and more homogeneous primary α particles in much shorter time. The microstructure evolution during isothermal treatment is studied and it is shown that the average particle diameter increases with the holding time and the shape coefficient decreases somewhat at first, and then decreases sharply in the end. It is discovered that alternating electromagnetic stirring is a good method to prepare semi-solid slurry with fine and relatively round primary particles.


2011 ◽  
Vol 311-313 ◽  
pp. 666-669
Author(s):  
Zheng Liu ◽  
Xiao Mei Liu ◽  
Yong Mei Hu

The semisolid A356 alloy slurry, which was grain-refined by Y2O3, was manufactured by low superheat pouring. The effects of grain-refine on the morphology and the grain size of the primary phase in semisolid A356 alloy were researched. The results indicated that semisolid A356 alloy contained Y2O3 with particle-like and rosette-like primary phases could be prepared by low superheat pouring. The grain size and particle morphology of primary phase in semisolid A356 alloy were markedly improved by Y2O3. The refining mechanism of Y2O3 on the morphology and the grain size of the primary α phase in semisolid A356 alloy was delved.


2006 ◽  
Vol 116-117 ◽  
pp. 344-349 ◽  
Author(s):  
Zhao Yang ◽  
J.W. Bae ◽  
C.G. Kang

In this paper, the influence of electromagnetic stirring on the grain size of A356 alloy inoculated by Al-5Ti-B was investigated. It is found that when stirring is applied at the same time with Al-5Ti-B, the inoculation effect will be disabled. X-ray determination and SEM observation show that stirring hinders the deposition of TiB2 particles; consequently hinder the formation of TiAl3 particles, which were proved to be the nucleus of primary α aluminum phase. If the stirring time is short, the grain size will be abnormally coarse. This experiment also confirms that the grain refinement of rheocasting is caused by dendrite fracture instead of modified nucleation.


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