scholarly journals Processing of Fe-based glass-forming alloys by the uniform-droplet spray process

2008 ◽  
Author(s):  
Suresh Kumar S. Pillai
Keyword(s):  
Spray Process ◽  
Glass Forming ◽  
Uniform Droplet Spray ◽  
Droplet Spray ◽  
Uniform Droplet

The Study on Heat Transfer and Solidification of Uniform Droplet Formed from Jet Breakup

2011 ◽  
Vol 121-126 ◽  
pp. 519-523
Author(s):  
Sheng Dong Gao ◽  
Yang Wang ◽  
Hong Bo Wang ◽  
Yan Wu
Keyword(s):  
Heat Transfer ◽  
Numerical Models ◽  
Metal Droplet ◽  
Spherical Powder ◽  
Spray Process ◽  
Jet Breakup ◽  
Droplet Stream ◽  
Droplet Spray ◽  
Uniform Droplet ◽  
Heat Transfer And Solidification

An experimental device capable of producing uniform metal droplet stream and electric charging and deflecting has been developed. Uniform spherical powder of 180μm in diameter was obtained after cooling and solidification. Numerical models of heat transfer and solidification of droplets were established. The thermal history including solid fraction of droplets in uniform droplet spray process were calculated. Under the common processing conditions, the cooling rate of a droplet of 180μm diameter is of the order of 103−104°C/s. To obtain homogeneous and dense preforms, the substrate should be positioned at a distance of 1.1-1.3m from the nozzle.

Thermal Modeling of Deposit Solidification in Uniform Droplet Spray Forming

1997 ◽  
Vol 119 (3) ◽  
pp. 332-340 ◽  
Author(s):  
P. Acquaviva ◽  
Chen-An Chen ◽  
Jung-Hoon Chun ◽  
Teiichi Ando
Keyword(s):  
Thermal State ◽  
Liquid Fraction ◽  
Solidification Process ◽  
Spray Forming ◽  
Forming Process ◽  
Material Microstructure ◽  
Precise Control ◽  
Uniform Droplet Spray ◽  
Droplet Spray ◽  
Uniform Droplet

In spray forming, the deposit thermal state is a key parameter which influences the microstructural evolution upon and after droplet impact onto the deposit. The uniform droplet spray (UDS) forming process has been developed to enable precise control of the droplet and deposit thermal state and the resultant material microstructure. By having a uniform droplet size throughout the spray, all the droplets deposited onto the substrate will have the same thermal state upon impact, allowing for precise control of the solidification process. This paper describes a one-dimensional, finite difference model that predicts the temperature and liquid fraction of the deposit during the UDS process. The model employs an explicit temperature-enthalpy method to incorporate a variety of solidification models. Experiments were conducted using Sn-15 wt percent Pb binary alloy. Temperatures were measured in the deposit and acceptable agreement with the simulation was obtained. Modeling has shown that the deposit thermal state is highly dependent on variations in spray conditions, which are predicted using droplet trajectory and droplet thermal models. Using the droplet and deposit models, the relationship between UDS process parameters and material microstructure can be understood.

Numerical Simulation of Molten Metal Droplet Impinging in Uniform Droplet Spray Rapid Prototyping

2011 ◽  
Vol 704-705 ◽  
pp. 680-684 ◽  
Author(s):  
Feng Liang Yin ◽  
Sheng Zhu ◽  
Jian Liu ◽  
Yuan Yuan Liang
Keyword(s):  
Numerical Simulation ◽  
Surface Tension ◽  
Rapid Prototyping ◽  
Solidification Process ◽  
Solid Substrate ◽  
The Body ◽  
Molten Droplet ◽  
Uniform Droplet Spray ◽  
Droplet Spray ◽  
Uniform Droplet

A two-dimensional mathematical model has been developed to simulate the impinging and solidification process of a single droplet onto substrate in uniform droplet spray rapid prototyping. Droplet free surface is tracked by volume-of-fluid (VOF) algorithm. The effect of surface tension on the droplet is taken into consideration by means of considering surface tension to be a component of the body force. The governing equations are solved using a finite volume formulation. The calculation results predicted the final shape of a molten droplet impacting onto a solid substrate, and revealed that the solidification process began at the leading edge with the spread process of droplet. The simulation results provide insight and information not easy available from experimental. Keywords: numerical simulation, droplet, rapid prototyping

scholarly journals Uniform-droplet spray forming

1997 ◽  
Author(s):  
C A Blue ◽  
V K Sikka ◽  
Jung-Hoon Chun ◽  
T Ando
Keyword(s):  
Spray Forming ◽  
Uniform Droplet Spray ◽  
Droplet Spray ◽  
Uniform Droplet

Design and Study of Master-Slave Fast Online Monitoring System Based on the PC MUC

2014 ◽  
Vol 898 ◽  
pp. 783-786
Author(s):  
Long He
Keyword(s):  
Monitoring System ◽  
Online Monitoring ◽  
Computer Control ◽  
Welding Process ◽  
Single Chip ◽  
Validity And Reliability ◽  
Computer Control System ◽  
Spray Process ◽  
Online Monitoring System ◽  
Droplet Spray

Based on the independent variables normalized mathematical thought and the combination of PC communication technology, this paper designs master-slave fast online monitoring system, the system includes computer control system, PC single chip communication system and intelligent robot system. In order to verify the validity and reliability of the system, the system is applied the online monitoring experiment of GMAW welding droplet spray process, to detect the shoot down process parameters. Finally, we get the heat flux density with the change curve of distance and voltage current, to provide a reliable experimental data for the design of intelligent automation welding process.

Numerical Simulation on Deposition and Solidification Processes of a Molten Metal Droplet Generated by Drop-on-Demand Jetting

2012 ◽  
Vol 538-541 ◽  
pp. 890-894 ◽  
Author(s):  
Peng Yun Wang ◽  
He Jun Li ◽  
Le Hua Qi ◽  
Hai Liang Deng ◽  
Han Song Zuo
Keyword(s):  
Numerical Simulation ◽  
Substrate Temperature ◽  
Metal Droplet ◽  
Dimensional Accuracy ◽  
Droplet Deposition ◽  
On Demand ◽  
Drop On Demand ◽  
Solidification Processes ◽  
Droplet Spray ◽  
Uniform Droplet

Droplet deposition and solidification is vital to dimensional accuracy and mechanical properties of components prepared by uniform droplet spray (UDS) forming. In this paper, a volume-of-fluid (VOF) based model was developed to study the deposition and solidification processes of a 1 mm Al-4.5%Cu droplet generated by drop-on-demand jetting. The effects of droplet falling velocity (0.6-0.8 m/s), initial temperature (933-973 K), and substrate temperature (300-473 K) were investigated. The results show that the final morphology of the deposited droplet is largely dependent on falling velocity and substrate temperature. The solidified droplet obtained from an UDS experiment validates the numerical simulation.

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