| This paper mainly studied that variation of microstructure and properties and mechanism ofaction of ZL702aluminum alloy which solidified naturally after the action of steady magneticfield. Firstly, it studied variation of microstructure of ZL702aluminum alloy under thefollowing circumstances: without magnetic field, with magnetic field, different magneticinduction intensity and different action time using comparative experiments. Secondly, itcompared the effects of magnetic fields on the mechanical properties of materials andexplored the mechanism. Finally, the microstructure, grain morphology and phases wereanalyzed taking advantage of scanning electron microscopy and X-ray diffraction and theauthor’s point of view was put forward. Through research, this paper arrives at the followingconclusions:⑴After action of steady magnetic field, the microstructure of ZL702aluminum alloychanged. By contrast the microstructure of samples with magnetic field and without magneticfield, large bone-shaped silicon phases were found in microstructure of sample and the siliconphases showed bone-shaped appeared aggregate or flocculent state. Solid solution and agingtreatment T6had a little impact on the samples after magnetic field. Duration of action of themagnetic field (greater than1minute) did not affect the effect of magnetic field on ZL702aluminum alloy.⑵From the phase diagram of view, magnetic flux density had a significant effect on theeffect of magnetic field. The greater the intensity of the magnetic induction was, the moreobvious effects were. And more silicon phases showed bone-shaped and more flocculentgroups were found in phase diagram. On the contrary, the flocculent groups were little. Whenthe magnetic flux density was less than10mT, phenomenon was not obvious. When themagnetic flux density greater than300mT, the affect of magnetic field on the microstructure of ZL702aluminum alloy changed little and on the mechanical properties changed withincreasing intensity of magnetic induction.⑶After magnetic field, elongation of ZL702aluminum alloy got improved and the tensilestrength changed little. Elongation of samples after magnetic field increased by31%andelongation was related to the intensity of the magnetic induction and had nothing to do withaction time.⑷Alloy after magnetic field crystal morphology varied by scanning electron microscopy(SEM) analysis. From the X-ray diffraction of view, phase s and degree of crystallization ofalloys varied little. |
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