摘要
真空感应熔炼气雾化技术(VIGA技术)是气雾化法制备高性能球形金属及金属合金粉末的主流雾化制粉技术,但目前关于紧耦合气雾化机制的细节仍然不甚清楚,缺乏核心理论。由于VIGA制粉过程是在密闭高温环境下气液耦合,难以观察细节,本文模拟采用VIGA技术在不同的雾化气压下制备Cu-Al-Ni合金粉末,并基于CFD技术,利用Fluent软件对雾化过程中气液两相流的相互作用进行建模,模拟雾化过程中不同雾化气压下铜铝镍合金熔液的一次破碎和二次破碎过程。模拟结果表明,雾化气压从6 MPa增加到8 MPa,流场最大速度从470 m/s增加到520 m/s,导流管末端的静压力从-30 kPa增加到40 kPa;一次雾化过程导流管端口的径向压强存在压力梯度,熔体从导流管中流出形成液膜,在回流区与气流膨胀区交界处被气流破碎成初始液滴,雾化压力越大,初始液滴越小;二次雾化过程是初始液滴继续破碎,粉末的粒度分布在20~100μm范围内,雾化压力升高,粉末的中值粒径会有所减小,但减小幅度不大;VIGA设备喷嘴的设计会存在一个临界值,到达临界值后流场内各个数值变化不大,因此雾化气压在7~8 MPa时,粉末粒径减小不明显。
Vacuum induction melting gas atomization technology(VIGA technology)is the mainstream atomization technology for preparing high-performance spherical metal and metal alloy powders by gas atomization method.However,the details of closely coupled gas atomization mechanism are still unclear and lack of core theory.Due to the gas-liquid coupling during the VIGA powder production process in a closed and high-temperature environment,it is difficult to observe the details.This article simulates the preparation of Cu-Al-Ni alloy powder using VIG technology under different atomization pressures.Based on CFD technology,Fluent software is used to model the interaction between gas-liquid two-phase flow during the atomization process,simulating the primary and secondary crushing processes of copper aluminum nickel alloy melt under different atomization pressures during the atomization process.The simulation results show that the atomization pressure increases from 6 MPa to 8 MPa,the maximum velocity of the flow field increases from 470 m/s to 520 m/s,and the static pressure at the end of the delivery tube increases from-30 kPa to 40 kPa.During the primary atomization process,there is a pressure gradient in the radial pressure of the delivery tube port.The melt flows out of the delivery tube to form a liquid film,which is broken into initial droplets by the airflow at the junction of the reflux zone and the airflow expansion zone.The higher the atomization pressure,the smaller the initial droplets;the secondary atomization process is that the initial droplets continue to break,and the particle size of the powder is within 20~100μm,as the atomization pressure increases,the median particle size of the powder decrease,but the decrease is not significant;the design of VIGA equipment nozzles have a critical value,and after reaching the critical value,the various values in the flow field do not change significantly.Therefore,the reduction of powder particle size is not significant between 7 MPa and 8 MPa.
作者
赵航
王晓峰
ZHAO Hang;WANG Xiaofeng(Department of Mechanical&Electrical Engineering,Shaanxi University of Science and Technology,Xi'an 710021,China)
出处
《中国有色冶金》
CAS
北大核心
2023年第4期65-72,共8页
China Nonferrous Metallurgy
关键词
真空感应熔炼气雾化技术(VIGA)
Cu-Al-Ni合金粉末
高压气雾化
气体流场
粒径分布
初始液滴
径向压力梯度
vacuum induction-melting gas atomizationtechnology(VIGA technology)
Cu-Al-Ni alloy powder
high pressure gas atomization
gas flow field
particle size distribution
initial condensate
radical pressure gradient
