Temperature variation and solution treatment of high strength aluminum alloy were investigated with temperature data acquisition system,microstructural observation,mechanical properties test,electrical conductivity me...Temperature variation and solution treatment of high strength aluminum alloy were investigated with temperature data acquisition system,microstructural observation,mechanical properties test,electrical conductivity measurement and differential scanning calorimetry(DSC) analysis.Specimens with two dimensions were employed in the experiment.The results indicate that the specimens with large size undergo low solution temperature and short time,giving rise to the reduction of hardening precipitates.The optimized solution treatments for specimens with dimensions of 25 mm×25 mm×2.5 mm and 70 mm×60 mm×20 mm are(480 ℃,30 min) and(480 ℃,90 min),respectively.The densities of GP zones and η' phases of the small specimen are higher than those of the large specimen,which is consistent with the properties of the alloys.展开更多
Mg-5Li-3Al-2Zn-xCe(x=0-2.5;mass fraction,%) alloys were prepared by casting,and heat treatments of homogenization at 300 °C and solid solution at 370 °C were carried out.The microstructure and tensile prop...Mg-5Li-3Al-2Zn-xCe(x=0-2.5;mass fraction,%) alloys were prepared by casting,and heat treatments of homogenization at 300 °C and solid solution at 370 °C were carried out.The microstructure and tensile properties of as-cast alloys and their evolutions after solid solution were investigated.The results show that with the increase of Ce content,Al2Ce/Al3Ce precipitates are formed and the alloys mainly consist of α-Mg,Al2Ce,Al3Ce and AlLi phases,and the amount of AlLi and Al-Ce intermetallics decreases after solid solution.The content and morphology of the second phases have important effects on the mechanical properties of the alloys;the alloy with 1.0%Ce content exhibits excellent tensile strength.The tensile strength and elongation of Mg-5Li-3Al-2Zn-0.5Ce alloy is remarkably improved by the solution strengthening effect because of the addition of Ce.展开更多
The corrosions resulting from defects in painting layers frequently occur in Al alloys, so the application of corrosion preventing systems is also very important. Optimum conditions in terms of electrochemistry in rel...The corrosions resulting from defects in painting layers frequently occur in Al alloys, so the application of corrosion preventing systems is also very important. Optimum conditions in terms of electrochemistry in relation to solution treatment, quenching and artificial aging treatment were established in order to optimize precipitation strengthening conditions intended to enhance the strength of Al alloys. Slow strain rate tests (SSRT) at various applied potentials were conducted in potential range from -1.8 to 0.5 V. The results show that the maximum tensile strengths, elongations and time-to-fracture are shown to be high values. After precipitation strengthening heat treatment, a tendency appear that time-to-fracture increases as elongation increases. In the potential range from -1.3 V to -0.7 V, the specimens show excellent mechanical properties, and thus this range is considered to be a corrosion prevention range.展开更多
AM50-4%(Zn,Y)alloy with a Zn/Y mole ratio of6:1was subjected to thermal analysis,and the results were used for designing a two-step progressive solution treatment process.The effects of solution and aging treatments o...AM50-4%(Zn,Y)alloy with a Zn/Y mole ratio of6:1was subjected to thermal analysis,and the results were used for designing a two-step progressive solution treatment process.The effects of solution and aging treatments on the microstructure and mechanical properties of the AM50-4%(Zn,Y)alloy were investigated using OM,XRD,SEM/EDS,TEM,tensile test and hardness test.The experimental results demonstrated that the two-step progressive solution treatment could make theΦandβphases sufficiently dissolve into the matrix which possessed higher supersaturated degree of the dissolved solute compared with the one-step solution treatment.This resulted in a certain enhancement of the precipitation strengthening effect during the subsequent aging process.The precipitation of theФphase had a greater impact on the comprehensive mechanical properties of the alloy thanβphase precipitation when the aging treatment was performed at180℃.The peak aging strength of the AM50-4%(Zn,Y)alloy which was subjected to the two-step progressive solution treatment process(345℃for16h and375℃for6h)was obtained after the aging treatment at180℃for12h.展开更多
基金Project(2010DFB50340) supported by the International Technical Cooperation ProjectProject(50904010) supported by the National Natural Science Foundation of China
文摘Temperature variation and solution treatment of high strength aluminum alloy were investigated with temperature data acquisition system,microstructural observation,mechanical properties test,electrical conductivity measurement and differential scanning calorimetry(DSC) analysis.Specimens with two dimensions were employed in the experiment.The results indicate that the specimens with large size undergo low solution temperature and short time,giving rise to the reduction of hardening precipitates.The optimized solution treatments for specimens with dimensions of 25 mm×25 mm×2.5 mm and 70 mm×60 mm×20 mm are(480 ℃,30 min) and(480 ℃,90 min),respectively.The densities of GP zones and η' phases of the small specimen are higher than those of the large specimen,which is consistent with the properties of the alloys.
基金Project (51001034) supported by the National Natural Science Foundation of ChinaProjects (2008AA4CH044, 2009AA1AG065,2010AA4BE031) supported by the Key Project of Science and Technology of Harbin City, China+2 种基金Project (HEUCF201210004) supported by the Fundamental Research Funds for the Central Universities,ChinaProject (20092304120020) supported by the Research Fund for the Doctoral Program of Higher Education,ChinaProject (11553054) supported by the Project of Science and Technology of Heilongjiang Province Education Department,China
文摘Mg-5Li-3Al-2Zn-xCe(x=0-2.5;mass fraction,%) alloys were prepared by casting,and heat treatments of homogenization at 300 °C and solid solution at 370 °C were carried out.The microstructure and tensile properties of as-cast alloys and their evolutions after solid solution were investigated.The results show that with the increase of Ce content,Al2Ce/Al3Ce precipitates are formed and the alloys mainly consist of α-Mg,Al2Ce,Al3Ce and AlLi phases,and the amount of AlLi and Al-Ce intermetallics decreases after solid solution.The content and morphology of the second phases have important effects on the mechanical properties of the alloys;the alloy with 1.0%Ce content exhibits excellent tensile strength.The tensile strength and elongation of Mg-5Li-3Al-2Zn-0.5Ce alloy is remarkably improved by the solution strengthening effect because of the addition of Ce.
文摘The corrosions resulting from defects in painting layers frequently occur in Al alloys, so the application of corrosion preventing systems is also very important. Optimum conditions in terms of electrochemistry in relation to solution treatment, quenching and artificial aging treatment were established in order to optimize precipitation strengthening conditions intended to enhance the strength of Al alloys. Slow strain rate tests (SSRT) at various applied potentials were conducted in potential range from -1.8 to 0.5 V. The results show that the maximum tensile strengths, elongations and time-to-fracture are shown to be high values. After precipitation strengthening heat treatment, a tendency appear that time-to-fracture increases as elongation increases. In the potential range from -1.3 V to -0.7 V, the specimens show excellent mechanical properties, and thus this range is considered to be a corrosion prevention range.
基金Project (201602548) supported by Liaoning Province Natural Science Foundation,ChinaProject (1711800) supported by Shenyang Science and Technology Plan,China+1 种基金Project (LQGD2017032) supported by Youth Project of Liaoning Education Department,ChinaProjects (51504153,51571145) supported by the National Natural Science Foundation of China
文摘AM50-4%(Zn,Y)alloy with a Zn/Y mole ratio of6:1was subjected to thermal analysis,and the results were used for designing a two-step progressive solution treatment process.The effects of solution and aging treatments on the microstructure and mechanical properties of the AM50-4%(Zn,Y)alloy were investigated using OM,XRD,SEM/EDS,TEM,tensile test and hardness test.The experimental results demonstrated that the two-step progressive solution treatment could make theΦandβphases sufficiently dissolve into the matrix which possessed higher supersaturated degree of the dissolved solute compared with the one-step solution treatment.This resulted in a certain enhancement of the precipitation strengthening effect during the subsequent aging process.The precipitation of theФphase had a greater impact on the comprehensive mechanical properties of the alloy thanβphase precipitation when the aging treatment was performed at180℃.The peak aging strength of the AM50-4%(Zn,Y)alloy which was subjected to the two-step progressive solution treatment process(345℃for16h and375℃for6h)was obtained after the aging treatment at180℃for12h.