| The effects of the chemical composition, rolling process and heat treatment parameters on the texture of the sheet and further on the formation of the deep drawing and ironing have been studied by utilizing the industrialized production line and the testing methods and instruments such as photoelectric spectrometry, eared rate, modeled formation of the deep drawing, mechanical property testing, metal texture, scanning electron microscope, X ray recrystallization, electrical conductivity measurement etc. Through utilization of the theories of the texture & earring and the dislocation & slipping, the effects of the sheet production process factors on the indexes of the deep drawing have been discussed. The stable batch production process of the sheet and strip for the shell of the mobile phone battery has been decided through a series of the process tests. And the technical indexes such as good surface quality, excellent punching and ironing performances and as well the various properties and thickness accuracy of the sheets having been produced are superior to the same category products of the aluminum sheet and strip for the case-shape pieces like the mobile phone shells. The new alloys with greater n value are generated by adjusting the contents of the Mn, Cu and Mg in the 3003 alloys as the matrix. The formed new alloys have high strengths and can resist the high temperature creeps, of which the expansion is smaller when the cases are internally compressed. The deep drawing properties of the 3003-H14 materials annealed in the salt bath can be improved than the original ones, the formation of which is easy. When the sheets without earring are produced by the annealing way, the Fe>Si has to be controlled to prevent the occurring of the greater earrings of 0°and 90°. And it is more suitable that the Fe/Si is controlled in the scope of 1.0-1.8. In the meantime the effects of the elements such as Cu, Mn, Ti, and Zn etc. on the earring are studied. The hot rolling process of the material for the shells of the mobile phone is chosen that the temperature of the upstream air flow is 550℃, while the downstream air flow is 530℃; the heating time is 10~12h; the metal temperature is 490~520℃; the time of temperature holding is 1h. The regression equation of the annealed alloys characteristics under different temperatures has been obtained through testing. The methods of determining the n and r values have been worked out; the yield-to-strength ratio, the n and r values etc. of the common aluminum alloys materials for deep drawing have been determined; the percentage content of the texture in the typical condition has been measured; the pole map has been drawn. In the process of recrystallization testing the conclusions are obtained that the strength of the materials is decreased gradually, the plasticity is improved, and the earrings in the directions of 0°and 90°are less than that in the direction of 45°from 360℃to 380℃; the material texture below 360℃is that the deformed texture is stronger than the recrystallized one, while above 360℃the recrystallized one becomes stronger obviously; at 210℃or so the material conductivity is increased greatly and this is the starting temperature of recrystallization; until 360℃there is a turning, i.e. the turning point from the cubic texture to the deformed one. The material various defects, which are caused by the production processing of the aluminum sheets for the cases work-pieces like the battery shells of the mobile phones, and occurred in the process of deep drawing and ironing are explained from theory in this paper. And in the same ways the problems such as the flow liners, surface wrinkling and coarsening, and the cracking of the deep drawing of the various products like the detonator belts, pen caps, cosmetics lids and senior tamperproof bottle caps etc. in the course of their industrial production have been solved. |
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