Physic Simulation of Slurry Preparation by Ultrasonic Vibration in Semisolid Metal Processing

2011 ◽  
Vol 704-705 ◽  
pp. 1279-1283
Author(s):  
Jun Wen Zhao ◽  
Shu Sen Wu ◽  
Guang Ze Dai ◽  
Jing Han ◽  
Xing Min Huang
Keyword(s):  
Fluid Flow ◽  
Ultrasonic Vibration ◽  
High Viscosity ◽  
Nucleation And Growth ◽  
Semisolid Slurry ◽  
Preparation Process ◽  
Metal Processing ◽  
Visualization Experiments ◽  
Slurry Preparation ◽  
Mixture System

In current research, a series of visualization experiments simulating the action of ultrasonic vibration (UV) in metal slurry preparation process on fluid flow, grain nucleation and growth as well as its interaction with viscosity of fluids were conducted. In these visualization experiments, the metal slurry maker was substituted by a transparent cup while the liquid and semisolid slurry of metal were replaced by other fluids or mixture system with similar characteristics. Scaled-up UV was applied to the liquid or mixture systems. The simulation shows that UV can roll up the particles at the bottom of the cup and make the liquid convection intense below the radiating surface of sonotrode while weak above it. UV can break dendrites rapidly and distribute them in melt. High viscosity reduces the actual power transmitted into liquid, and higher viscosity requires higher inception power of UV.

scholarly journals Trace element catalyses mineral replacement reactions and facilitates ore formation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yanlu Xing ◽  
Joël Brugger ◽  
Barbara Etschmann ◽  
Andrew G. Tomkins ◽  
Andrew J. Frierdich ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Trace Elements ◽  
Fluid Flow ◽  
Large Scale ◽  
Metal Accumulation ◽  
Nucleation And Growth ◽  
Reaction Interface ◽  
Ore Formation ◽  
Key Factor ◽  
Mineral Replacement

AbstractReaction-induced porosity is a key factor enabling protracted fluid-rock interactions in the Earth’s crust, promoting large-scale mineralogical changes during diagenesis, metamorphism, and ore formation. Here, we show experimentally that the presence of trace amounts of dissolved cerium increases the porosity of hematite (Fe2O3) formed via fluid-induced, redox-independent replacement of magnetite (Fe3O4), thereby increasing the efficiency of coupled magnetite replacement, fluid flow, and element mass transfer. Cerium acts as a catalyst affecting the nucleation and growth of hematite by modifying the Fe2+(aq)/Fe3+(aq) ratio at the reaction interface. Our results demonstrate that trace elements can enhance fluid-mediated mineral replacement reactions, ultimately controlling the kinetics, texture, and composition of fluid-mineral systems. Applied to some of the world’s most valuable orebodies, these results provide new insights into how early formation of extensive magnetite alteration may have preconditioned these ore systems for later enhanced metal accumulation, contributing to their sizes and metal endowment.

Simulation on the Thixocasting Process of the Turbocharger Impellers and Selection of the Viscosity Models

2014 ◽  
Vol 217-218 ◽  
pp. 219-224 ◽  
Author(s):  
Fan Zhang ◽  
Xiao Gang Hu ◽  
Da Quan Li ◽  
You Feng He ◽  
Xiao Jing Xu ◽  
...  
Keyword(s):  
Solid Fraction ◽  
High Speed ◽  
High Viscosity ◽  
Shrinkage Porosity ◽  
Die Design ◽  
Semisolid Slurry ◽  
Filling Process ◽  
Viscosity Models ◽  
Defect Control ◽  
Porosity Defects

The thixocasting technology is chosen to produce the turbocharger impellers as it is capable of producing castings with high precision dimension, free of oxide and shrinkage porosity defects and therefore long service life. The thixocasting turbocharger impellers have the similar mechanical property to those produced by forging and machine processes, but much less costs. In the thixocasting process, the semisolid slurry with certain solid fraction is injected into mould at a high speed. Since high viscosity and thixotropic characteristics, the semisolid slurry reveals unique flow condition and characteristics in the filling process. So, its very desirable for the die design, process optimization, and defect control to visualize the high-speed filling process of semisolid slurry by numerical simulation. In this paper, several commonly used viscosity models for semisolid slurry are analysed. The Power law cut-off model (PLCO) model is selected to simulate the filling process in the thixocasting process of the impellers of 319s alloy, compared with actual results by partial filling testing. The causes of the casting defects are also analysed, indicating that the simulation results can accurately reproduce the filling process of semisolid slurry, and PLCO model is a successful choice for simulating the filling process of semisolid slurry with high solid fraction.

scholarly journals CIRCULATORY HIGH-VISCOSITY NONNEWTONIAN FLUID FLOW IN A SINGLE-SCREW EXTRUDER CHANNEL

2016 ◽  
pp. 97-107
Author(s):  
Maria Andreevna PONOMAREVA ◽  
◽  
Maria Petrovna FILINA ◽  
Vladimir Albertovich YAKUTENOK ◽  
◽  
...  
Keyword(s):  
Fluid Flow ◽  
High Viscosity ◽  
Screw Extruder ◽  
Single Screw ◽  
Single Screw Extruder

Effect of Rotating Magnetic Field on Microstructure Evolution of Pb-Bi Alloys

2011 ◽  
Vol 311-313 ◽  
pp. 600-608
Author(s):  
Zhao Chen ◽  
Xiao Li Wen ◽  
Chang Le Chen
Keyword(s):  
Magnetic Field ◽  
Fluid Flow ◽  
Microstructure Evolution ◽  
Solidification Process ◽  
Nucleation And Growth ◽  
Primary Phase ◽  
Rotating Magnetic Field ◽  
Growth Behaviour ◽  
Solidification Behaviour ◽  
40 Hz

Solidification behaviour of Pb-Bi alloys under rotating magnetic field (RMF) was investigated experimentally to understand the effect of the frequency of RMF on the nucleation and growth behaviour. It was found that, as the increase of the rotating frequency, the grains are fragmented and refined gradually until a transition from columnar to equiaxed microstructures happens at a rotating frequency of 40 Hz. Moreover, the Bi concentration of the primary phase decreases and macrosegregation is eliminated effectively with RMF. These are due to the effect of RMF on the nucleation, growth and fluid flow in the solidification process.

Analytical Model for Heat Transfer Phenomena in Cup-Cast Method

2006 ◽  
Vol 116-117 ◽  
pp. 569-572
Author(s):  
Farshid Pahlevani ◽  
J. Yaokawa ◽  
M. Itamura ◽  
M. Kikuchi ◽  
O. Nagasawa ◽  
...  
Keyword(s):  
Heat Transfer ◽  
A356 Alloy ◽  
Nucleation And Growth ◽  
Heat Transfer Model ◽  
Solid Particles ◽  
Transfer Model ◽  
Heat Transfer Phenomenon ◽  
Semi Solid ◽  
Slurry Preparation ◽  
Good Agreement

Cup-cast method is a new method deals with semi-solid slurry preparation recently developed by the authors. In this method, suspension of globular solid particles in molten metal is prepared by controlling the nucleation and growth of solid-particles through the simplest and quickest techniques. In this method, heat transfer phenomenon plays an important role in governing the shape, size, and fraction of solid particles. In the current study, a heat transfer model was proposed and applied to Al-A356 alloy semi-solid slurry preparation. The heat transfer model was based on heat balance consideration between cup and slurry and it was in a good agreement with experimental results.

F121 Visualization Experiments of a Vapor Chamber (Fluid Flow Characteristics in a Sintered Wick)

2009 ◽  
Vol 2009 (0) ◽  
pp. 155-156
Author(s):  
Tomoaki Zaizen ◽  
Yasushi Koito ◽  
Shuichi Torii ◽  
Toshio Tomimura ◽  
Masataka Mochizuki
Keyword(s):  
Fluid Flow ◽  
Flow Characteristics ◽  
Vapor Chamber ◽  
Visualization Experiments ◽  
Fluid Flow Characteristics ◽  
Chamber Fluid

Preparation and rheocasting of semisolid slurry of 5083 Al alloy with indirect ultrasonic vibration process

2011 ◽  
Vol 528 (29-30) ◽  
pp. 8635-8640 ◽  
Author(s):  
Shulin Lü ◽  
Shusen Wu ◽  
Chong Lin ◽  
Zuqi Hu ◽  
Ping An
Keyword(s):  
Ultrasonic Vibration ◽  
Semisolid Slurry ◽  
Al Alloy ◽  
Vibration Process ◽  
5083 Al Alloy

Effect of slurry preparation process on electrochemical performances of LiCoO2 composite electrode

2010 ◽  
Vol 195 (18) ◽  
pp. 6049-6054 ◽  
Author(s):  
Gil-Won Lee ◽  
Ji Heon Ryu ◽  
Woojoo Han ◽  
Kyung Hyun Ahn ◽  
Seung M. Oh
Keyword(s):  
Composite Electrode ◽  
Electrochemical Performances ◽  
Preparation Process ◽  
Slurry Preparation

scholarly journals Analysis of the effect of ultrasonic vibration on nanofluid as coolant in engine radiator

2021 ◽  
Vol 5 (5 (113)) ◽  
pp. 6-13
Author(s):  
Sudarmadji Sudarmadji ◽  
Santoso Santoso ◽  
Sugeng Hadi Susilo
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Fluid Flow ◽  
Transfer Coefficient ◽  
Ultrasonic Vibration ◽  
Flow Rate ◽  
Volume Concentration ◽  
Aluminum Oxide Nanoparticles ◽  
Particle Volume ◽  
Overall Heat Transfer Coefficient

The paper discusses the combined methods of increasing heat transfer, effects of adding nanofluids and ultrasonic vibration in the radiator using radiator coolant (RC) as a base fluid. The aim of the study is to determine the effect of nanoparticles in fluids (nanofluid) and ultrasonic vibration on the overall heat transfer coefficient in the radiator. Aluminum oxide nanoparticles of 20–50 nm in size produced by Zhejiang Ultrafine powder & Chemical Co, Ltd China were used, and the volume concentration of the nanoparticles varied from 0.25 %, 0.30 % and 0.35 %. By adjusting the fluid flow temperature of the radiator from 60 °C to 80 °C, the fluid flow rate varies from 7 to 11 lpm. The results showed that the addition of nanoparticles and ultrasonic vibration to the radiator coolant increases the overall heat transfer coefficient by 62.7 % at a flow rate of 10 liter per minute and temperature of 80 °C for 0.30 % particles volume concentration compared to pure RC without vibration. The effect of ultrasonic vibration on pure radiator coolant without vibration increases the overall heat transfer coefficient by 9.8 % from 385.3 W/m2·°C to 423.3 W/m2·°C at a flow rate of 9 liter per minute at a temperature of 70 °C. The presence of particles in the cooling fluid improves the overall heat transfer coefficient due to the effect of ultrasonic vibrations, nanofluids with a volume concentration of 0.25 % and 0.30 % increased about 10.1 % and 15.7 %, respectively, compared to no vibration. While, the effect of nanoparticles on pure radiator coolant at 70 °C enhanced the overall heat transfer coefficient by about 39.6 % at a particle volume concentration of 0.35 % compared to RC, which is 390.4 W/m2·°C to 545.1 W/m2·°C at 70 °C at a flow rate of 10 liter per minute

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