Effect of grain refining on primary α phase in semi-solid A356 alloy prepared by low superheat pouring and slight electromagnetic stirring

2008 ◽  
Vol 21 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Z LIU
Keyword(s):  
A356 Alloy ◽  
Electromagnetic Stirring ◽  
Grain Refining ◽  
Α Phase ◽  
Semi Solid ◽  
Low Superheat

A Compound Process Preparing Semi-Solid A356 Alloy Slurry

2010 ◽  
Vol 97-101 ◽  
pp. 1003-1007 ◽  
Author(s):  
Zheng Liu ◽  
Wei Min Mao
Keyword(s):  
Grain Size ◽  
Nucleation Rate ◽  
A356 Alloy ◽  
Electromagnetic Stirring ◽  
Structure Morphology ◽  
Compound Process ◽  
Semi Solid ◽  
Low Superheat

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.

Research of Preparing Parameters in the Complex Process on Microstructure in Semisolid A356 Alloy Slurry with Micro-Addition of La

2016 ◽  
Vol 877 ◽  
pp. 114-120
Author(s):  
Zheng Liu ◽  
Li Na Xu ◽  
Jia Yi Zhang ◽  
Guang Zhu Bai ◽  
Xiao Mei Liu
Keyword(s):  
A356 Alloy ◽  
Low Frequency ◽  
Electromagnetic Stirring ◽  
Pouring Temperature ◽  
Complex Process ◽  
Stirring Time ◽  
Semisolid Alloy ◽  
Addition Amount ◽  
Low Superheat

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.

Application of Frequency Conversion in Preparation of Semisolid A356 Alloy Slurry

2012 ◽  
Vol 430-432 ◽  
pp. 886-889 ◽  
Author(s):  
Zheng Liu ◽  
Fu Yong Wang ◽  
Kai Cao ◽  
Hong Biao Xu ◽  
Mei Yan Huang
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Frequency Conversion ◽  
A356 Alloy ◽  
Electromagnetic Stirring ◽  
Low Superheat

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.

The Refinement Mechanism of La-Ce Binary Alloy on Primary α Phase in A356 Alloy under Electromagnetic Stirring

2014 ◽  
Vol 217-218 ◽  
pp. 340-346
Author(s):  
Zheng Liu ◽  
Hao Lin Luo ◽  
Qing Chun Chen
Keyword(s):  
Binary Alloy ◽  
Frequency Conversion ◽  
Eutectic Reaction ◽  
A356 Alloy ◽  
The Other ◽  
Electromagnetic Stirring ◽  
Α Phase ◽  
Refinement Mechanism ◽  
Re Elements ◽  
Shape And Size

The refining effects of La-Ce binary alloy on the primary α phase in semisolid A356 alloy prepared by electromagnetically stirred were researched, in which the refinement mechanism of the binary alloy on primary α phase were emphatically approached. The different amount of La-Ce was added into A356 melt, the melt was poured at 620°C and slightly electromagnetically stirred for 15s with an electromagnetic stirrer which was controlled by frequency conversion, then it was isothermally held at 615°C for 10min. The shape and size of primary α phase were measured, and the distribution of La and Ce was researched by SEM and EDS. The results indicated that the RE elements were easy to uniformly distribute around the primary α phase under electromagnetic stirring, and had the obvious refining effect on primary α phase in semisolid A356 alloy, in which there was the finer primary α phase with particle-like in the melt. The refinement mechanism of La-Ce binary alloy under electromagnetic stirring was concerned with the eutectic reaction between RE elements and Al in the melt, in which the α-Al phase resulted from the Al-RE eutectic reaction could serve as the nucleating site of the primary α phase during solidification of A356 alloy. The other reactant from the Al-RE eutectic reaction, Al11Ce3, was also directly used as nucleation of α phase during the solidification.

Microstructural Investigation of Semisolid Aluminum A356 Alloy Prepared by the Combination of Electromagnetic Stirring and Gas Induction

2019 ◽  
Vol 285 ◽  
pp. 290-295
Author(s):  
Nora Nafari ◽  
Farnoush Yekani ◽  
Hossein Aashuri
Keyword(s):  
Aspect Ratio ◽  
Shape Factor ◽  
A356 Alloy ◽  
Average Diameter ◽  
Electromagnetic Stirring ◽  
Microstructural Investigation ◽  
Porous Graphite ◽  
Three Phase ◽  
Semi Solid ◽  
Aluminum A356 Alloy

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.

Development of Microstructure of Semi-Solid A356 Alloy by Alternating Electromagnetic Stirring

2011 ◽  
Vol 266 ◽  
pp. 84-88
Author(s):  
Wen Liu ◽  
Ji Qiang Li ◽  
Xu Ding
Keyword(s):  
Particle Diameter ◽  
A356 Alloy ◽  
Good Method ◽  
Processing Parameters ◽  
Electromagnetic Stirring ◽  
Isothermal Treatment ◽  
Average Particle ◽  
Shape Coefficient ◽  
Magnetic Stirring ◽  
Semi Solid

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.

Microstructure Refinement by Y2O3 in Semisolid A356 Alloy

2011 ◽  
Vol 311-313 ◽  
pp. 666-669
Author(s):  
Zheng Liu ◽  
Xiao Mei Liu ◽  
Yong Mei Hu
Keyword(s):  
Grain Size ◽  
A356 Alloy ◽  
Particle Morphology ◽  
Primary Phase ◽  
Microstructure Refinement ◽  
Α Phase ◽  
Low Superheat

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.

Research on Effect of La on Microstructure in Semi-Solid A356 Alloy

2010 ◽  
Vol 139-141 ◽  
pp. 693-697 ◽  
Author(s):  
Xiao Mei Liu ◽  
Zheng Liu ◽  
Yong Mei Hu
Keyword(s):  
Binary Alloy ◽  
Master Alloy ◽  
Eutectic Reaction ◽  
A356 Alloy ◽  
Size And Morphology ◽  
Semi Solid ◽  
Low Superheat

Semi-solid A356 alloy slurry grain-refined by Al-La master alloy is prepared by low superheat pouring. The effects of La on the morphology and size of primary grain in semi-solid A356 alloy are researched. The results indicate that the semi-solid A356 alloy slurry with particle-like and rosette-like primary grains can be prepared by low superheat pouring. The size and morphology of the primary grain in semi-solid A356 alloy are markedly improved by La. The refining mechanism of La on the morphology and size of the primary grain in semi-solid A356 alloy is delved. The eutectic reaction of Al-La binary alloy provides the effective nuclei for formation of the primary grains in semi-solid A356 alloy.

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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