Research On Electrostatic Atomization Technology Of Spray Forming

Spray forming is a new forming technology of metals and alloys which is extremely rapid development in recent year, the perform produced by spray forming has rapid solidification characteristics of grain refining, tissue uniformity and inhibition of segregation, for spray forming process, atomization quality is a important factor that effect the quality of spray forming product. In this paper, the application of electrostatic atomization technology in spray forming will be present, aim is to make liquid alloy charging and use electrostatic force to reinforce atomizing process, furthermore, the atomization quality can be improved. The main research work is following: Firstly, design charging system of spray forming device; Then electrostatic interaction on gas flow field in spray forming is simulated, effect of some parameter on atomization process under electrostatic is discussed, and some experimental verification are present.There are three mode making droplet charged in electrostatic atomization process: corona charging, induction charging and contact charging. In this paper, the designed charging device mainly use inductive charging mode, few used contact charging mode,this charging device can be described: One pole of power contact with metal liquid through electrode bar, it is negative, the other pole of power contact with graphite gasket, it is positive, then between two poles built a capacitor, it will be induction charged while liquid alloy moved through capacitor. The design of direct current power device is an important equipment, so a optional direct current power device is designed, it mainly include adjustable voltage regulator ranged between 0-300V, rectifier bridge, electrolytic capacitors and capacitance, ammeter, voltmeter.Electrostatic interaction is applied to spray forming in this paper, the gas flow field model in the electric field is built. In FlUENT software, MHD modules is used, it can introduce electric field effect, then the electrostatic interaction of gas flow field in spray forming is simulated. Simulation results show that the distribution of atomization area pressure is more uniform and concentrate, the velocity is increased from 300m/s to 700m/s. It is explained that electrostatic has active effect on atomization process, and atomization quality of liquid metal can be improved under electrostatic field.On the basis of numerical simulation results, experimental of pressure is 1MPa, voltage is 200V and pressure is 1MPa, voltage is 0V are present, it is satisfied that the experimental results are consist with the simulated results. While pressure is 1.0MPa, voltage is 200V, there are a satisfied atomization phenomenon, axial pressure distribution is more uniform and concentrate, it helps to reduce the droplets splash and negative pressure at the nozzle decreases, the possibility of liquid metal anti-spray is decreased too.