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.

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.

Semi-Solid Processing of Nano-SiCP/ Al-Si Composites and Mechanical Properties with Rheo-Casting

2019 ◽  
Vol 285 ◽  
pp. 33-38
Author(s):  
Shu Sen Wu ◽  
Du Yuan ◽  
Qiang Chen ◽  
Shu Lin Lü ◽  
Zhi Wei Huang
Keyword(s):  
A356 Alloy ◽  
Average Diameter ◽  
Sem Analysis ◽  
Nano Particles ◽  
Mechanical Stirring ◽  
Sic Particles ◽  
New Process ◽  
The Matrix ◽  
A356 Aluminum ◽  
Semi Solid

Generally nano-SiC particles are difficult to be added into molten aluminum metals because of poor wettability. Nano-SiC particles reinforced A356 aluminum alloy composites were prepared by a new process, i.e., a molten-metal process combined with mechanical stirring at semi-solid state and ultrasonic vibration method. The nano particles were β-SiCp with an average diameter of 40 nm, and pre-oxidized at about 850°C to form an oxide layer with thickness of approximately 3.6 nm. The SEM analysis results show that nano-SiC particles are dispersed well in the matrix and no serious agglomeration is observed. The tensile strength and elongation of the 2wt.% nano-SiCp/A356 composite in as-cast state are 259 MPa and 5.3%, and they are improved by 20% and 15% respectively compared with those of the A356 alloy.

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.

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.

Numerical Modeling of Die Filling of Semi-Solid A356 Aluminum Alloy

2008 ◽  
Vol 141-143 ◽  
pp. 605-610 ◽  
Author(s):  
A. Foroughi ◽  
Hossein Aashuri ◽  
A. Narimannezhad ◽  
Ali Khosravani ◽  
M. Kiani
Keyword(s):  
A356 Alloy ◽  
Solidification Process ◽  
A356 Aluminum Alloy ◽  
Finite Element Software ◽  
Die Filling ◽  
Simulation Results ◽  
A356 Aluminum ◽  
Semi Solid ◽  
Constitutive Parameters ◽  
Aluminum A356 Alloy

Computer base and simulation technique have been applied for modeling the semi-solid die filling and part of the solidification process of aluminum A356 alloy. A fairly simple one-phase rheological model has been implemented into a fluid flow finite element software Procast, to solve the partial differential equations. This model is purely viscous nature and is implemented in the power law cut-off model of Procast. The constitutive parameters of this model were determined for a rheocast A356 alloy. Using these parameters and comparing the simulation results with experimental data showed good correlation with the model prediction. The designed die for rheocasting was applied for the production of a small propeller with thin section.

Control of Amount of α-Al Phase Particles in near Eutectic Al-Si Alloy by Electromagnetic Stirring

2022 ◽  
Vol 327 ◽  
pp. 250-254
Author(s):  
Yuichiro Murakami ◽  
Naoki Omura
Keyword(s):  
Solid State ◽  
Volume Fraction ◽  
Electromagnetic Stirring ◽  
Casting Alloy ◽  
Slow Cooling ◽  
Fraction Solid ◽  
Three Phase ◽  
Rotational Magnetic Field ◽  
Semi Solid ◽  
Si Content

Al-Si alloy is widely used as a casting alloy. The α-Al phase in the semi-solid state has low Si content in the Al-Si alloy. Then by separation of these α-Al phases from semi-solid Al-Si alloy, refining of aluminum can be possible. But, in near eutectic Al-Si alloy, few primary α-Al phases can be crystallized. If the fraction ratio of the α-Al phase can be increased, near eutectic Al-Si alloy can refine, and this method can be used for recycling. In this study, the effect of electromagnetic stirring (EMS) on the microstructure, especially the amount of the α-Al phase particles was investigated. A rotational magnetic field was applied to JIS ADC12 alloy which has near eutectic content during slow cooling from the liquid state to the solid-state, by using a three-phase AC coil. By applying EMS at solidification, the shape of the α-Al phase became particle shape from dendrite shape, and the amount of α-Al phase particles was increased. Moreover, by applying unidirectional intermittent EMS, the volume fraction of α-Al phase particles was decreased with increasing intermittent applying time. In ADC12 alloy, the primary α-Al phases can be crystallized only 10% generally, but it could be obtained over 40% by applying EMS. This means that the semi-solid slurry of near eutectic alloy with over 40% of fraction solid can be obtained by applying EMS.

Preparation of AlSi9Mg Alloy Semi-Solid Slurry by Electromagnetic Stirring Combined with Mechanical Vibration

2012 ◽  
Vol 192-193 ◽  
pp. 398-403
Author(s):  
Van Luu Dao ◽  
Sheng Dun Zhao ◽  
Wen Jie Lin ◽  
Chen Yang Zhang
Keyword(s):  
Shape Factor ◽  
Mechanical Vibration ◽  
Experimental Results ◽  
Electromagnetic Stirring ◽  
Mechanical Stirring ◽  
Fine Microstructure ◽  
Semi Solid

The electromagnetic stirring combined with mechanical stirring (EMSCMV) method was developed for preparing the AlSi9Mg alloy semi-solid slurry. The experimental results demonstrate that, the preparation of semi-solid slurry by EMSCMV is sufficient to obtain fine microstructure of billet. The primary -Al particles are small, spherical and uniform throughout the microstructure. When increasing the stirring power and the vibrating power, the size of primary -Al particles decreases while the shape factor increases, and its distribution is more uniform. The fine microstructure of billet prepared by EMSCMV was obtained at the stirring power of 2.0~2.4 kW and vibrating power of 0.8 kW.

A Control of Microstructure of A356 Alloy by Sequential Semi-Solid Process

2008 ◽  
Vol 141-143 ◽  
pp. 569-573
Author(s):  
Sung Chul Lim ◽  
Hai Joong Lee ◽  
Jang Won Kang ◽  
Sang Kil Lee ◽  
Kyung Hoon Kim ◽  
...  
Keyword(s):  
Die Casting ◽  
A356 Alloy ◽  
Flow Characteristics ◽  
Solid Particles ◽  
Electromagnetic Stirring ◽  
Cast Sample ◽  
Maintenance Time ◽  
Semi Solid ◽  
Original Strength ◽  
Electronic Parts

The study on rheocasting has been conducted based on examination for destruction, growth, ripening of solid state in accordance with various changes in cooling. And flow characteristics of slurry for high liquid range rather than practical use has gotten attention. However, the characteristics of existing rheocasting and thixocasting are better mechanical property than competing process die casting but it’s competitiveness as automotive or electric electronic parts which cost of product is important. And productivity also has been decreased. Because die-casting techniques has been advanced such as vacuum, mold auto temperature control etc. Most of the work reported at this conference concerned the semi-solid processing of low melting point alloys, and in particular light alloys of aluminum and magnesium. Therefore, the aim of this study is to devise the original strength of semi-solid process by sequential semi-solid process. The size of primary solid particle and the degree of sphericity as a function of the variation in cooling rate, stirring speed, and holding time were observed. By applying electromagnetic stirring, primary solid particles became finer and rounder relative to as-cast sample. With this background, this research conducted electromagnetic stirring through slurry deliverance of sequential process through A356 alloy electromagnetic stirring pump (30Hz, 130A) with Sequential Semi-Solid Process device to assess the microstructures, primary particle size, degree of sphericity change in A356 alloy in accordance of solid-fraction, stirring speed, and stirring maintenance time.

Semi-solid microstructure evolution during reheating of aluminum A356 alloy deformed severely by ECAP

2008 ◽  
Vol 466 (1-2) ◽  
pp. 67-72 ◽  
Author(s):  
S. Ashouri ◽  
M. Nili-Ahmadabadi ◽  
M. Moradi ◽  
M. Iranpour
Keyword(s):  
Microstructure Evolution ◽  
A356 Alloy ◽  
Semi Solid ◽  
Aluminum A356 Alloy
Sign in / Sign up

Export Citation Format

Share Document