THE OPTIMIZING CONDITIONS BY TAGUCHI METHOD FOR FABRICATING SEMI-SOLID Al–Zn–Mg ALLOY SLURRY BY COOLING PLATE METHOD

In order to optimize the condition for the semi-solid Al–Zn–Mg aluminium alloy fabricated by cooling plate method, the Taguchi design was used. The cooling plate method effectively separating the grains formed from the mold wall can be used to form a semi-solid material by flowing molten metal over an inclined Cu plate and casting in a mold for the near-net shape component. In Taguchi's design method, the higher signal vs noise (S/N) ratio the better. Therefore, the manufacturing conditions were arranged as a table of orthogonal arrays (L9(34)), and the influence of two factors, pouring temperature and cooling plate angle, was examined. From the observed microstructures, the grain size and aspect ratio were measured by image analyzer. The results indicated that the pouring temperature exerts the main effect on the spherical microstructures since the S/N ratio, which is the sensibility of the surrounding environment, was the highest. The optimum condition for the Al–Zn–Mg alloy was a cooling plate angle of 40° and a pouring temperature of 680°C. The grain size and aspect ratio were 70 μm and 1.3, respectively.

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The analysis of variance on process parameters affecting the microstructures of semi-solid Al-Zn-Mg alloy billet by cooling plate method

Metals and Materials International ◽

10.1007/s12540-010-1223-0 ◽

2010 ◽

Vol 16 (6) ◽

pp. 1009-1017 ◽

Cited By ~ 4

Author(s):

Sung-Yong Shim ◽

Dae-Hwan Kim ◽

Seung-Hwa Chio ◽

Yeong-Hwa Kim ◽

He Bai ◽

...

Keyword(s):

Analysis Of Variance ◽

Process Parameters ◽

Mg Alloy ◽

Plate Method ◽

Cooling Plate ◽

Semi Solid

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The Determination of Semi-Solid Processing Ability Using a Novel Rheo-Characterizer Apparatus

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.141-143.343 ◽

2008 ◽

Vol 141-143 ◽

pp. 343-348 ◽

Cited By ~ 2

Author(s):

Manel da Silva ◽

Alain Lemieux ◽

Hugues Blanchette ◽

X. Grant Chen

Keyword(s):

Grain Size ◽

Cutting Temperature ◽

Solid Material ◽

Processing Conditions ◽

Grain Refiner ◽

Processing Ability ◽

Working Principle ◽

Semi Solid ◽

The Impact

The “Rheo-Characterizer” is an apparatus designed to assess the quality control of the semi-solid material. The working principle is based on the recording and subsequent analysis of the force required to transversally cut the semi-solid slurry at constant speed. Semi-solid slurries produced under different conditions while using the SEED process were analyzed with the “Rheo- Characterizer”. The TiB2 grain refiner was also added to evaluate the impact on the microstructure and the cutting force. The microstructural features were measured and the grain size was analyzed for the different processing conditions. The effect of the cutting temperature on the resulting curve was also investigated. The results show that the “Rheo-Characterizer” is capable of differentiating between the varied microstructural morphologies and the solid fraction of the billet.

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The Role of Alloy Design in Semi-Solid Casting of Ductile Iron Processed by Inclined Cooling Plate

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.457.287 ◽

2010 ◽

Vol 457 ◽

pp. 287-292 ◽

Cited By ~ 1

Author(s):

Bashir Heidarian ◽

Mahmoud Nili-Ahmadabadi ◽

Marzyeh Moradi

Keyword(s):

Cast Iron ◽

Reliable Method ◽

Ductile Cast Iron ◽

Forming Process ◽

Plate Method ◽

Equilibrium Conditions ◽

Cooling Plate ◽

Solidification Range ◽

Semi Solid

The inclined Cooling Plate process can be considered as a reliable method for the production of semi-solid ductile cast iron. By utilizing aforesaid method, the main limitation of common semi-solid methods, i.e. Mg fading, will be eliminated. The present research is intended that the importance of alloying design through the inclined cooling plate method and its profound effect on obtaining the optimum solidification range for thixo-forming process have been illustrated. The optimization of solidification range for thixo-forming process has been gained by the simulation in both equilibrium and non-equilibrium conditions. Afterwards the alloy selection has been performed amongst several alloying composition with a view to their effect on the thixo-forming process and austempering.

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Refinement of Primary Silicon Grains in Semi-Solid Al-25%Si Hypereutectic Aluminum Alloy Slurry

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.285.153 ◽

2019 ◽

Vol 285 ◽

pp. 153-160 ◽

Cited By ~ 1

Author(s):

Wei Min Mao ◽

Peng Yu Yan ◽

Z.K. Zheng

Keyword(s):

Grain Size ◽

Aluminum Alloy ◽

Research Work ◽

Good Method ◽

Primary Silicon ◽

Pouring Temperature ◽

Channel Bend ◽

Traditional Process ◽

Semi Solid ◽

Inner Channel

s: The semi-solid slurry of Al-25%Si hypereutectic aluminum alloy was prepared through a copper serpentine pouring channel, the effect of pouring temperature and numbers of channel bend on the slurry microstructure was investigated. The results show that the primary silicon grains in Al-25%Si hypereutectic alloy solidified at a traditional condition are very large and the average silicon grain size is about 65.3μm, however, when the liquid Al-25%Si alloy is poured through a copper serpentine pouring channel, the primary silicon grains are fined obviously. If the channel has three bends and the pouring temperature is 747°C,the average silicon grain size in the slurry is about 33.7μm. If the channel has four bends and the pouring temperature is 747°C, the average silicon grain size in the slurry is about 30.9μm. If the channel has seven bends and the pouring temperature is 747°C, the average silicon grain size in the slurry is about 28.6μm. The analysis shows that the chilling effect of the inner channel wall precipitates primary silicon nuclei, and so the primary silicon grains of Al-25%Si alloy are fined greatly. Meanwhile, the subsequent washing of the alloy melt also promotes the separation of primary silicon grains from the inner wall and the primary silicon grains are further fined. The above research work demonstrates eventually that the copper serpentine pouring channel process is a good method for fining the primary silicon grains in hypereutectic Al-25%Si alloy rather than using chemical fining agent phosphorus as in traditional process.

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Application of Inclined Cooling Plate to Fabrication of Semi-Solid Cast Iron

Materials Science Forum ◽

10.4028/www.scientific.net/msf.544-545.195 ◽

2007 ◽

Vol 544-545 ◽

pp. 195-198 ◽

Cited By ~ 2

Author(s):

Sung Yong Shim ◽

Hwan Goo Seong ◽

Jin Ho Jeong ◽

Su Gun Lim

Keyword(s):

Cast Iron ◽

Solidification Rate ◽

Optical Microscope ◽

Peak Hardness ◽

Image Analyzer ◽

Cast Irons ◽

Cooling Plate ◽

Relative Extent ◽

Iron Specimen ◽

Semi Solid

The influence of angles of inclined cooling plate on cast structure and mechanical properties of cast iron was investigated experimentally in 3.1 wt.% C containing hypoeutectic semisolid cast irons fabricated by flowing the molten melt over the inclined cooling plate and pouring into a preheated permanent mold. The variables used in this study were angles of the cooling plate (5 ~ 15 deg) and the mold temperatures (500~700 deg). The microstructure of resultant specimens were characterized by measuring grain sizes of primary austenite and its solid fraction, using an optical microscope equipped with a digital image analyzer. It was shown that the spherical-like austenite (1.4 aspect ratio) was formed at the cast iron specimens prepared in employing a 10 deg angle of the inclined cooling plate. This was ascribed to the relative extent of duration time of the flowing melt which determine the solidification rate of the melt. The peak hardness and impact values were achieved in the semi-solid cast iron specimen with relatively more spherical austenite. The measured values were approximately 44HRC and 1.71 J/cm2.

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Statistical Analysis for Influence of Factors on Morphological Evolution in Semi-Solid Al-6Zn-2.5Mg-0.5Cu Alloy by Cooling Plate Method

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.l-mz201130 ◽

2011 ◽

Vol 52 (5) ◽

pp. 862-867 ◽

Cited By ~ 6

Author(s):

Sung-Yong Shim ◽

Dae-Hwan Kim ◽

Young-Rok Seong ◽

Su-Gun Lim

Keyword(s):

Statistical Analysis ◽

Morphological Evolution ◽

Plate Method ◽

Cooling Plate ◽

Semi Solid

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

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.327.255 ◽

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.

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Optimum Design of Journal Bearings Dimensions for Rotating Machines

Engineering and Technology Journal ◽

10.30684/etj.v38i10a.1093 ◽

2020 ◽

Vol 38 (10A) ◽

pp. 1481-1488

Author(s):

Tariq M. Hammza ◽

Ehab N. Abas ◽

Nassear R. Hmoad

Keyword(s):

Aspect Ratio ◽

Dynamic Response ◽

Numerical Solution ◽

Critical Speed ◽

Design Method ◽

Considerable Effect ◽

Journal Bearings ◽

Rotating Machines ◽

Bearing Clearance ◽

Study Results

The values of Many parameters which involve in the design of fluid film journal bearings mainly depend on the bearing applied load when using the conventional design method to design the journal bearings, in this study, as well as applied bearing load, the dynamic response and critical speed have been used to calculate the dimensions of journal bearings. In the field of rotating machine, especially a heavy-duty rotating machines, the critical speed and response are the main parameters that specify bearing dimensions. The bearing aspect ratio (bearing length to bore diameter) and bearing clearance have been determined based on rotor maximum critical speed and minimum response displacement. The analytical solution of rotor Eq. of motion was verified by numerical solution via using ANSYS Mechanical APDL 18.0 and by comparing the numerical solution with the preceding study. The final study results clearly showed that the bearing aspect ratio has little effect on the critical speed, but it has a high effect on the dynamic response also the bearing clearance has little effect on the critical speed and considerable effect on the dynamic response. The study showed that the more accurate values of bearing aspect ratio to make the response of rotor as low as possible are about 0.65 - 1 and bearing percent clearance is about 0.15 - 0.2 for different rotor dimensions.

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Effect of Vanadium Reinforcement on the Microstructure and Mechanical Properties of Magnesium Matrix Composites

Crystals ◽

10.3390/cryst11070806 ◽

2021 ◽

Vol 11 (7) ◽

pp. 806

Author(s):

Liqing Sun ◽

Shuai Sun ◽

Haiping Zhou ◽

Hongbin Zhang ◽

Gang Wang ◽

...

Keyword(s):

Grain Size ◽

Grain Refinement ◽

Milling Process ◽

Mg Alloy ◽

Matrix Composites ◽

Magnesium Matrix Composites ◽

Pinning Effect ◽

Average Grain Size ◽

The Matrix ◽

Hot Press Sintering

In this work, vanadium particles (VP) were utilized as a novel reinforcement of AZ31 magnesium (Mg) alloy. The nanocrystalline (NC) AZ31–VP composites were prepared via mechanical milling (MM) and vacuum hot-press sintering. During the milling process, the presence of VP contributed to the cold welding and fracture mechanism, resulting in the acceleration of the milling process. Additionally, increasing the VP content accelerated the grain refinement of the matrix during the milling process. After milling for 90 h, the average grain size of AZ31-X wt % Vp (X = 5, 7.5, 10) was refined to only about 23 nm, 19 nm and 16 nm, respectively. In the meantime, VP was refined to sub-micron scale and distributed uniformly in the matrix, exhibiting excellent interfacial bonding with the matrix. After the sintering process, the average grain size of AZ31-X wt % VP (X = 5, 7.5, 10) composites still remained at the NC scale, which was mainly caused by the pinning effect of VP. Besides that, the porosity of the sintered composites was no more than 7.8%, indicating a good densification effect. As a result, there was little difference between the theoretical and real density. Compared to as-cast AZ31 Mg alloy, the microhardness of sintered AZ31-X wt % VP (X = 5, 7.5, 10) composites increased by 65%, 87% and 96%, respectively, owing to the strengthening mechanisms of grain refinement strengthening, Orowan strengthening and load-bearing effects.

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