| 5xxx series aluminum alloys belong to Al-Mg alloys in deformed aluminum alloys,in which Mg is the main element,and its content ranges from 3wt.%to 5wt.%,which cannot be heat-treated and strengthened.This alloy is widely used in aviation,aerospace,shipbuilding and welded structural parts because of its low density,good plasticity,high strength and extensibility,excellent fatigue and welding performance,and good corrosion resistance.Among them,the 5083 alloy is the preferred material for ships.Mainly through work hardening and micro-alloying to improve the overall performance of the alloy.Therefore,how to formulate a matching thermomechanical treatment process can play a greater role in the effective strengthening phase in the alloy,reducing the effects of pitting corrosion,intergranular corrosion,exfoliation corrosion,and electrochemical corrosion on aluminum alloys is a subject worthy of study.In this paper,Al-Mg-Ag alloys with different properties were obtained on the basis of 5083 aluminum alloy,by adding different amounts of Ag elements,and through smelting ingots,homogenization treatment,hot rolling-solid solution-cold rolling deformation and aging treatment.The effect of different amounts of Ag on the microstructure and properties of 5083 aluminum alloy was experimentally studied.Analyze and discuss the Ag content that has the most obvious influence on the aging strengthening of' the alloy and determine the best aging system.In addition,by analyzing the influence of Ag element under different thermomechanical treatment processes on the microstructure and properties of 5083 aluminum alloy,the optimal thermomechanical treatment process system was determined.The main conclusions of the experiment are as follows:(1)The addition of Ag in 5083 aluminum alloy can promote the precipitation of the second phase and grain refinement to a certain extent;and the content of Ag can affect the quantity and morphology of the second phase.(2)Comprehensively analyze and compare the electrical conductivity,hardness.strength and extensibility in the Aging process of 5083 aluminum alloy with different Ag content.When the aging temperature is 160? and the aging time is 24h,the mechanical properties of 5083 Aluminum Alloy with Ag Content of 0.6wt.%are best,and the aging strengthening effect is the best.(3)The precipitation phase of the alloy in the peak ageing strengthening phase is T-phase Mg2(Ag,Al)3,a=1.41 nm.The phase size is small,about 8 nm,and it is uniformly dispersed in the aluminum matrix.(4)With the increase of aging time,the intergranular corrosion resistance and electrochemical corrosion resistance of 5083 aluminum alloy with Ag content of 0.6wt.%are all decreased.Among them,the corrosion resistance is the worst when the aging time is 24h.In solid solution-cold rolling-aging treatment,the mass loss per unit area before and after corrosion of the 5083 aluminum alloy was 54.326mg/cm2,the open circuit potential was-0.706V,and the corrosion current density was 0.322 mA·cm-2.(5)Compared with the solution-cold rolling-aging treatment,the mechanical properties of the 5083 aluminum alloy after cold rolling-solid solution-secondary cold rolling-ageing treatment are reduced,and the corrosion resistance is improved.When the 5083 aluminum alloy with Ag content of 0.6wt.%is at the peak aging time of aging at 160? for 24h,the hardness is 121.3,which is decreased by 27.4,the tensile strength is 430.0MPa,which is reduced by 12.6Mpa,the yield strength is 284.2MPa,which is reduced by 22.5MPa,and the extensibility is 1 8.0%,which is an increase of 1.36%;The mass loss per unit area before and after corrosion was 23.766mg/cm2,which is decreased by 30.559mg/cm2,the open circuit potential was-0.715V,which had a positive shift of 0.008 V,the corrosion current density was 1.530mA·cm-2,which had an increase of 1.208mA·cm-2. |
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