| 5083 aluminum alloy belongs to Al-Mg series alloy.The alloy has the advantages of small density,high tensile strength and good corrosion resistance,and is widely used in the marine field.However,due to the poor strengthening effect of precipitates in the aging process,Al-Mg alloy can not be strengthened by heat treatment,so the strength of the alloy is greatly limited.In this experiment,different contents of Ag elements were added into 5083 aluminum alloy,The alloy is treated by melting casting,homogenizing treatment,rolling deformation and solution aging treatment.By comparing the hardness curve of 5083 aluminum alloy with different Ag aging at different temperature and time,the effect of Ag on aging strengthening was studied and the optimum aging system was determined.In addition,by comparing the hardness curves of Al-Mg-Ag alloy with different Mg aging at different temperature and time,the influence of Mg content on aging strengthening of Al-Mg-Ag alloy was investigated.The conclusions are as follows:(1)The addition of Ag element can refine grain of as cast 5083 alloy.The number of the second phase and the hardness of as cast alloy increase with the content of Ag in the alloy.(2)By comparing the hardness and electrical conductivity of 5083 aluminum alloy with different content of Ag,the strengthening effect of alloy aging at 160?is the best,and the peak hardness is the highest than the alloy aging at other temperatures.(3)The hardness of 5083 alloy increases with the content of Ag.When adding 0.6 wt%Ag,the peak hardness of the alloy aging at 160? is 117.3HV,which is 24.7HV higher than the alloy without Ag.The tensile strength is 448.9MPa and the yield strength is 272.5MPa,which is 53.4MPa and 95.4MPa higher than the alloy without Ag respectly.The hardness value of the peak strengthening stages of 5083 alloy with 0.8 wt%Ag has little difference from that of 0.6 wt%Ag.Therefore,the addition of 0.6 wt%Ag in 5083 aluminum alloy is the best.(4)The precipitate phase of alloy during peak aging stage is circle-like T phase Mg32(Ag,Al)49,a=1.41nm.The size of the phase is about 5nm.During the over-aged stages,the precipitate phase grows into rod-like and with the size of about 100nm.(5)The hardness value of Al-Mg-Ag alloy increases with the Mg content in the aging process.The peak hardness of Al-6Mg-0.6Ag alloy aging at 210? for 24h is 26.6HV higher than that of Al-2Mg-0.6Ag alloy.The strengthening phase is T phase which distribute in the matrix uniformly. |
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