Technical Study Of Preparing Al-Cu-Mg Alloy And Improvement Of Spray Conform Equipment

As a newly proposed material forming new technology, spray Conform has many advantages of spray deposition and Conform. It is suitable for high strength and low plasticity alloy arid difficult forming materials of continuous production of small and medium size tube, rod, section bar and wire rod. This technology has many characteristics, such as high efficiency, energy saving, near net shape, short process, and so on. The products have high density, small and uniform microstructure, no macro segregation, good performance, etc. To deeply investigate the technology, it has a important influence of high strength and low plasticity, and high alloy materials preparation and development of new forming technology and the development. To this end, this thesis has carried on the following work and research about the technology:(1) On the basis of the research group’s test and work, equipment of spray Conform is modified in the following working, such as smelting equipment and its auxiliary components, regional controller, diversion pipe and its auxiliary components, lift system, support system of extrusion shoe, limit device of extrusion shoe, hydraulic systems of extrusion shoe. As well as the equipment of Spray deposition and regional equipment is reinstalled and matched with the Conform machine. The structure of equipment of spray Conform becomes more compact and reasonable. The improved equipment is used for the test of spray Conform, obtaining the φ7mm,φ8mm and φ9mm spray Conformed Al-Cu-Mg alloy.(2) With2A12aluminum alloy as the research object, many parameters are selected such as Ⅲ type nozzle, Ⅲ type nozzle, diversion pipe distancing from nozzle of3mm, the atomizing gas pressure of0.3MPa and the distance of regional controller’s between two big roll of10mm, two small roller of spacing of7mm, superheating temperature of200℃, the big speed of roller of1500r/min, the distance of deposition parameters of260-350mm, finally obtain relatively high density and area narrower deposition billet.(3) Along the extrusion direction, microstructure of spray Conformed Al-Cu-Mg alloy is composed of alternately hat-like coarse-grained layer and fine-grained layer. Crystal layer width thickness is related to the cooling rate. To this end, by reducing atomization gas pressure, increasing the extrusion wheel speed, the cooling speed is increased, the coarse-granular layer width is decreased, and the fine-crystal layer width is increased. Microstructure of the product tends to be small and uniform.(4) By microstructure analysis of spray Conformed Al-Cu-Mg alloy, it is process of the spray Conform forming microstructure evolution mechanism that is studied. The study provides some reference for the research of this technology.(5) Density of spray conformed Al-Cu-Mg alloy can be up to99.8%, and its mechanics performance is tested and analysed. tensile strength (Rm) is305MPa, yield strength (Rpo.2) is153MPa, elongation (A) was11.7%, reduction of area (Z) was22.2%, the value of Rpo.2/Rm is0.502. At the end of plastic deformation, engineering stress-strain curve appears serrated.This characteristic is different from the conventional forming state of materials engineering stress-strain curve, its formation and the microstructure of spray Conformed Al-Cu-Mg alloy has a close relationship.(6) The cooling rate of spray Conform process is calculated, and the cooling rate is greater than1.98×104K/s.