| 7A04 aluminum alloy belongs to Al-Zn-Mg-Cu system alloy,which can be strengthened by heat treatment.Due to its high strength and good processing performance,it is an indispensable lightweight structural materials for the aerospace and the military industry.However,due to the complexity of the traditional aging heat treatment process and the long aging time,there are problems such as low production efficiency.The properties of high strength aluminum alloy mainly depend on its matrix structure and the distribution of the second phase precipitates,while the distribution and morphology of the second phase precipitates are mainly affected by the process system of solid solution and aging treatment.The essence of the aging process is the precipitation of solute atoms ejecting from supersaturated solid solution,is also the process of nucleation growth.Therefore,under the premise that electromagnetic energy can promote nucleation rate,electromagnetic energy is applied during the aging process of aluminum alloy,which to explore the influence of electromagnetic energy on the precipitation and mechanical properties of aluminum alloy during aging.In this paper,the aluminum alloy cast by applying electromagnetic energy during solidification is selected as the research object.By applying electromagnetic energy during the aging process of aluminum alloy,the aging precipitation process is accelerated,the aging time is shortened,and exploration in 100~140 ℃ temperature range limitation of electromagnetic energy temperature and time affect the size and distribution of aluminum alloy;In the process of electromagnetic energy aging,the effect of magnetic field intensity on precipitate of aluminum alloy was analyzed by changing the parameters of electromagnetic energy.The surface morphology and precipitate distribution of aluminum alloy were observed by environmental scanning electron microscope,the Vickers hardness of the aluminum alloy after the aging of the electromagnetic energy was measured by a digital Vickers hardness tester and the influence of different electromagnetic energy aging process on hardness of aluminum alloy was analyzed.The aluminum alloy was conduct totensile test after the electromagnetic energy aging treatment by using the micro-control electronic universal testing machine,and the influence of the electromagnetic energy aging on the tensile strength and elongation of the aluminum alloy was analyzed.The results show that electromagnetic energy can promote the aging behavior of7A04 aluminum alloy,When the magnetic induction intensity is 22.3 mT and the aging process is 130 ℃/60 min,the aging process of the aluminum alloy can be accelerated,the nucleation rate is promoted,the more uniform dispersion precipitates.In the electromagnetic energy aging process of 7A04 aluminum alloy,the size of precipitate will be affected by the magnetic induction intensity.With the increase of magnetic induction intensity,the size of precipitates gradually increases.When the magnetic induction increased from 22.3 mT to 50.54 mT,the precipitate size increased from 0.183 μm to0.553 μm.After being aged by electromagnetic energy,the tensile strength of aluminum alloy can reach 506 Mpa,the elongation up to 17%,and the vickers hardness up to 144 HV. |
PDF Full Text Request