Spray Deposition Deposition Zone Control

This paper mainly studies regional control of Spray Deposition Process,in order to resolve this problem that the larger conventional spray regions are unable to directly match the continuous extrusion process(3).Although the present technology on Spray Deposition is very mature, so far there is no related report for its regional control problem at home and abroad. Therefor the direction of this study has some novelty and innovation.The research first self-designed the spray deposition small devices, including the nozzles, honeycomb duct, melting device, receiving device, cooling device, high pressure gas installations, protection device. Then, on the basis of this device we carried out the following experiments:simulations of water spray deposition, spray deposition of metal lead,5052 aluminum alloy spray deposition.The results of Water spray deposition simulation show that the linear nozzle jet in the free state is more narrow and more close to the rectangular shape. It determines that the linear nozzle is a better match than central hole nozzle for continuous extrusion machine extrusion wheel slot.In metal spray deposition experiment, honeycomb ducts of 60 and 120 degree Chamfer were used. The result shows that in the same atomization pressure, with the vary of extended length of the tube, the draft tube of 120 degree Chamfer is easier to form a negative pressure effect, more conducive to the flow of molten metal. In addition, negative pressure changes relatively smaller and spray deposition process is more stable. So the experiment confirmed honeycomb ducts of 120 degree Chamfer is the preferred device. With linear nozzle and honeycomb ducts of 120 degree Chamfer, baffles and air knife,which control spray deposition region,were respectively used for lead spray deposition experiments,under condition of Baffle spacing of 16～20mm,gas slot width of 20～60mm, air knife gas pressure of 1Mpa, angle lo～3o. The results showed that in the experiment baffle were blocked by metal lead. This is because the temperature of metal lead decreases rapidly under the influence of high-pressure atomizing cold air flow, and when it is sprayed on the cold metal shield the solid fraction increases rapidly and it is easy to adhere to the both sides of metal baffles. In the process of spraying,the rapid accumulation of metal lead resulted in baffle channel obstruction. Under the action of air curtain, formed by the air knife, deposition region control of metal lead has been greatly improved,70 to 80% can be controlled at±35mm range.Theoretically, if the air knife pressure is large enough, you can control 100% of lead within the±35mm, even smaller area. In 5052 aluminum alloy spray deposition experiments, honeycomb duct was designed improvely and air knife in the 0.4～08MPa atomizing air pressure was used for the spray deposition experiments. The results showed that when atomization gas is 0.6MPa, the 80.7 percent of the 5052 deposition can be controlled within±30mm range, and the density of deposit perform is better.In short, under the action of air knife, he secondary device, pray deposition control of the region has made some progress by constantly optimizing the nozzle, honeycomb duct, and adjusting atomization gas pressure in spray deposition process, extended length of the pipe, gas pressure of air knife and other related process parameters. Currently 80 percent of the liquid metal can be controlled within about±30mm range, but there is a gap from the ultimate goal. So the relative experiment are carried out to find the ultimate Solutions of controlling the deposition region.