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.

Development of Microstructure of Semi-Solid 6061 Alloy with Method of Alternating Electromagnetic Stirring

2011 ◽  
Vol 199-200 ◽  
pp. 1870-1873
Author(s):  
Wen Liu ◽  
Jun Long Chen ◽  
Xiao Li Ma ◽  
Xu Ding
Keyword(s):  
Isothermal Holding ◽  
Particle Diameter ◽  
Electromagnetic Stirring ◽  
Isothermal Treatment ◽  
Average Particle ◽  
Average Particle Diameter ◽  
Shape Coefficient ◽  
Magnetic Stirring ◽  
Semi Solid ◽  
Α Particles

The semi-solid 6061 alloy was obtained with method of 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 increase of isothermal holding time and the shape coefficient decreases somewhat at first, and then decreases sharply in the end.

Development of Non-Dendritic Microstructure of Aluminum Alloy in Semi-Solid State under Ultrasonic Vibration

2008 ◽  
Vol 141-143 ◽  
pp. 451-456 ◽  
Author(s):  
Shu Sen Wu ◽  
Jun Wen Zhao ◽  
Li Ping Zhang ◽  
Ping An ◽  
You Wu Mao
Keyword(s):  
Ultrasonic Vibration ◽  
Isothermal Holding ◽  
Acoustic Streaming ◽  
Particle Diameter ◽  
Good Method ◽  
Processing Parameters ◽  
Al Alloy ◽  
Average Particle ◽  
Dendritic Microstructure ◽  
Semi Solid

The effect of processing parameters on the semi-solid microstructure has been investigated in the course of semi-solid slurry preparation of A356 Al alloy by ultrasonic vibration method. The A356 melt in temperature of 630660°C was poured into a special metal cup, and exposed to ultrasonic vibration at 20 kHz or isothermal holding for a certain time after vibration. The results show that the semi-solid slurry with primary α-Al crystals smaller than 90 μm and an average shape coefficient F S (SF was defined as SF4 A/L2P) above 0.5 could be prepared by ultrasonic vibration for a time less than 144 s. In the isothermal holding period after a short time of ultrasonic vibration, the average particle diameter increased with the increase of holding time, but F S decreased at first, and then increased a little. It was discovered that ultrasonic vibration is a good method to prepare semi-solid slurry with fine and relatively round primary crystals due to cavitation and acoustic streaming effects.

Rheoforging of thin case for IT devices with optimal process parameters and new type die design

2013 ◽  
Vol 228 (6) ◽  
pp. 1021-1028
Author(s):  
Yong Phil Jeon ◽  
Amir Bolouri ◽  
Hyung Yoon Seo ◽  
Jong Deok Kim ◽  
Chung Gil Kang
Keyword(s):  
Mechanical Properties ◽  
Cell Phone ◽  
Processing Parameters ◽  
Die Design ◽  
Electromagnetic Stirring ◽  
Forming Process ◽  
Processing Technologies ◽  
Promising Tool ◽  
New Type ◽  
Semi Solid

The latest trend in the cell phone component industry to use aluminium and magnesium alloys has resulted in the advanced processing technologies. Semi-solid forming process that is advantageous for the mass production of thin parts with complex shapes have been of interest as a promising tool for near net-shape manufacturing. This study describes a semi-solid forming process for the development of a 1 mm-thick cell phone case by using the rheological material prepared by electromagnetic stirring equipment. Thus, a new type of die design for indirect rheoforging was proposed to efficiently control the primary α-Al phase particles in the thin part under rheological conditions. Their microstructure and mechanical properties were investigated and compared to parts produced without electromagnetic stirring. Those products fabricated by electromagnetic stirring had better mechanical properties and globular microstructures than those fabricated without electromagnetic stirring. Several processing parameters such as punch velocity (30 mm/s), punch pressure (75–250 MPa), stirring time (10 s), and solid fraction (0–20%) were used. The optimal condition that resulted in a defect-free component with the improved mechanical properties was explained and discussed.

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.

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.

Study of the Precision Forging of an Impeller by Numerical Simulation and Test Forming

2008 ◽  
Vol 141-143 ◽  
pp. 593-598
Author(s):  
Wei Wei Wang ◽  
Fei Han ◽  
Shou Jing Luo
Keyword(s):  
Numerical Simulation ◽  
Flow Line ◽  
Processing Parameters ◽  
Hydraulic Press ◽  
Isothermal Treatment ◽  
Billet Temperature ◽  
Precision Forging ◽  
Die Structure ◽  
Semi Solid ◽  
Forging Die

In the present paper, the precision forging of an impeller was studied by means of numerical simulation and test forming. Based on the structure and dimension of the impeller, the combination structure was used in the forging die to obtain the extrusion deformation. The forming processes were simulated with DEFORM-3D for different billet dimensions and processing parameters. The parameters, which could ensure the forming quality of the impeller, were determined by the calculations and analysis. The die structure and the billet dimensions were determined according to the simulation results, and the forging die was designed and manufactured. The billet with semi-solid microstructure was produced by means of the direct heating-isothermal treatment. The forming was conduced in an YX-315F hydraulic press, and the precision forgings of the impeller were produced successfully. Both of the simulation and the forming test show that the impeller forging can be formed with the combination structure die and the extruding forming stale satisfactorily. The ideal parameters to produce the precision forgings of the impeller are: billet temperature at 625°C, die temperature at 450°C and punch speed at 20mm/s. Under these conditions, forgings of the impeller can be produced with plump blades, smooth outer surface, and good flow line. This can match the requirements of the precision forging of impellers.

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.

The MSCP Process for Semi-Solid Slurry Production

2006 ◽  
Vol 116-117 ◽  
pp. 362-365 ◽  
Author(s):  
Zhan Feng Tian ◽  
Zhi Feng Zhang ◽  
Jun Xu ◽  
Li Kai Shi
Keyword(s):  
Continuous Production ◽  
Electromagnetic Stirring ◽  
Preparation Process ◽  
High Quality ◽  
Magnetic Stirring ◽  
Continuous Preparation ◽  
The Common ◽  
Feedstock Production ◽  
Electro Magnetic ◽  
Semi Solid

Production of semi-solid slurry with fine and uniform microstructures is one of the basic and key problems for the industrial application of semi-solid processing. The common disadvantages of existing techniques are as follows: continuous production difficulty, high process controlling requirement and low quality microstructure. In order to overcome those problems, the MSCP (Multielectromagnetic Stirring Continuous Preparation) process has been developed by GRINM. Experimental results show that annular chamber for feedstock production can improve the efficiency of electromagnetic stirring and reduce the difficulty of temperature grad control. Compared with single electromagnetic stirring, multi- electro magnetic stirring can achieve more uniform stirring. Strict temperature grad control in annular chamber is the key of continuous preparation of high quality semi-solid slurry. Semi-solid slurry of different solid fractions was obtained by MSCP.

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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