Study Of Aluminum Alloy 2A12 By Spray Deposition And Hot Extrusion Process

The process of spray deposition and hot extrusion is the previously studies of spray and conform to hard forming material. The ultimate aim is to make the spray deposition technology and conform technology to achieve combination effectively. Although the wheel round groove of conform machine is narrow (only 10mm to 15mm), the uncontrolled deposition area is large. In order to improve the rate of product, various factors must be considered comprehensively. By designed a spray deposition system equipments and flow injection control equipment, control deposition area is the first purpose of this paper. We designed a hot extrusion system equipments and extrusion billet of spray deposition, which simulation of the conform process. By determined the extrusion temperature of extrusion parameters, low plastic material can achieve the best performance, and these parameter can used for subsequent conform process.In this paper, the system devices of spray deposition and hot extrusion are designed and manufactured. They include:melting system, spray system, jet control system, hot extrusion system. Such as melting system:the size of the crucible and induction coil for the electromagnetic induction furnace. Spray system:the size of atomizer and diversion pipe. Jet control system:the analysis of roll for control and atomizer bracket. Hot extrusion system: Analysis and choice of the die, container and stem. And used this devises, The 5052 aluminum alloy is carried out spray deposition and jet control experiments, And the 2A12 aluminum alloy, which is a hard forming material, is carried out spray deposition and hot extrusion experimentThe principle of the experiment is trying to control deposition area in the context of guarantee the sedimentary organization. The experiment of spray deposition and area control of 5052 aluminum is proposed in this paper, because of the aluminum alloying isn't high and easy to form. And The sprayer is chosen by experimenting, and the results show that the four-way plug sprayer is much better than the V-type one. The type of the diversion pipe with a interior dimensions of 2x10mm and 2x10mm are also chosen. Some parameters of spray deposition is determined, and the experiments show a fact that the spray deposition area decreases with the minishing of the pressure of spraying. However, a very low pressure would lead emerging of cast structure, and the most acceptable pressure is varying from 0.4-0.6MPa. The diversion pipe will be easy to plug if the length of the diversion pipe is greater than 5mm, and the most acceptable length is 3mm. The superheat of metal is chosen about100℃, Too high to lead cast structure, too low to lead looser and grain grows.Some parameters of the streamline flow controller are determined. The sprayer is located at the lowest point, and the wheel of the sprayer runs faster, the results seem better. However, affected by the circulation of cooling water, the maximum rotation speed of the wheel is 1500r/min. Parameters of the spray deposition and flow control system are further confirmed by spray deposition experiments of 2A12 aluminum alloy. The best deposition area and tissue of deposited billet are obtained if the pressure of spray is 0.4MPa and the other parameters are the same as the experiment of spray deposition of 5052 aluminum.Deposited billets, which are obtained at the one of the parameters, are placed into the subsequent hot extrusion equipment system, and the extrusion products and pressure of extrusion at different extrusion temperate are analyzed. The analyses show a fact that the higher the extrusion temperature, the higher the strength of extruded products, but the plasticity decreases with the increase of temperate. If the extrusion temperate is too low(<350℃), the equipment will not work normally, even abnormally stop. If the extrusion temperate is too high(>450℃), it will lead to serious recrystallization, and the grain grows. The products, which are extruded from the spray billets at the temperate of 420℃, and treated by the T6 heat treatment, show excellent mechanical properties. Hence, the superiority of the process is proved.