The correlation between Si content （0.1%-0.5%, mass fraction） and pulse laser welding performance of AI-Mn-Mg aluminum alloy sheets was studied. The sheets were fabricated in the laboratory, with gauge of 0.45 mm, H...The correlation between Si content （0.1%-0.5%, mass fraction） and pulse laser welding performance of AI-Mn-Mg aluminum alloy sheets was studied. The sheets were fabricated in the laboratory, with gauge of 0.45 mm, H16 temper by pulse laser welding. It was found that no cracking existed in the welding pool as Si content was below 0.34%. However, when the Si content increased to 0.47%, cracking formed in the welding pool. Microstructure observations indicated that residual eutectic phases distributed at the grain boundaries were discontinuous and appeared to be small particles in lower Si content alloys; the residual eutectic phases distributed at the grain boundaries were partially continuous and appeared to be films in higher Si content alloys. These phenomena could explain why Si content adversely affected the laser welding performance.展开更多
Two contents(1.5%and3%)of TiB2nanoparticles were introduced in Al?Mn?Mg3004alloy to study their effects on theelevated-temperature properties.Results show that TiB2nanoparticles were mainly distributed at the interden...Two contents(1.5%and3%)of TiB2nanoparticles were introduced in Al?Mn?Mg3004alloy to study their effects on theelevated-temperature properties.Results show that TiB2nanoparticles were mainly distributed at the interdendritic grain boundarieswith a size range of20?80nm,which is confirmed by transmission electron microscopy(TEM)and X-ray diffraction(XRD).Therefore,the volume fraction of the dispersoid free zones is greatly reduced and the motion of grain boundaries and dislocations isinhibited more effectively at elevated temperature.After peak precipitation heat treatment,the yield strengths in the alloy with3%TiB2addition at room temperature and300°C were increased by20%and13%respectively,while the minimum creep rate at300°Cwas reduced to only1/5of the base alloy free of TiB2,exhibiting a considerable improvement of elevated-temperature properties inAl?Mn?Mg alloys.展开更多
The microstructures of five Al Mn Mg alloys with different Mn, Si and Fe contents were investigated in as cast and homogenized states. The influences of chemical composition and homogenizing process on the microstruct...The microstructures of five Al Mn Mg alloys with different Mn, Si and Fe contents were investigated in as cast and homogenized states. The influences of chemical composition and homogenizing process on the microstructure were studied. The results show that the morphology of the primary second particles are not influenced by the variation of Mn, Si and Fe level, and the amount of the primary α phase, the α precipitates and Mg 2Si phase are enhanced by the addition of Si; The average size of primary intermetallic particles reduces and the volume fraction of them decreases slightly with the increase in homogenization temperature and time; However, the volume fraction of primary secondary particles is increased by adding more Mn, Si and Fe elements in alloys. Moreover, a new MgSiCu rich eutectic in the as cast ingot has been found.展开更多
基金National Natural Science Foundation of China(Nos.52001140,52274363)Guangdong Basic Applied Basic Research Foundation,China(Nos.2022A1515010558,2022A1515011597,2022A1515240065)。
基金Project(2011KJZD04)supported by the CHINALCO Science and Development Foundation,China
文摘The correlation between Si content （0.1%-0.5%, mass fraction） and pulse laser welding performance of AI-Mn-Mg aluminum alloy sheets was studied. The sheets were fabricated in the laboratory, with gauge of 0.45 mm, H16 temper by pulse laser welding. It was found that no cracking existed in the welding pool as Si content was below 0.34%. However, when the Si content increased to 0.47%, cracking formed in the welding pool. Microstructure observations indicated that residual eutectic phases distributed at the grain boundaries were discontinuous and appeared to be small particles in lower Si content alloys; the residual eutectic phases distributed at the grain boundaries were partially continuous and appeared to be films in higher Si content alloys. These phenomena could explain why Si content adversely affected the laser welding performance.
基金support from the Natural Sciences and Engineering Research Council of Canada(NSERC)and Rio Tinto,through the NSERC Industry Research Chair in Metallurgy of Aluminum Transformation at University of Quebec at Chicoutimi
文摘Two contents(1.5%and3%)of TiB2nanoparticles were introduced in Al?Mn?Mg3004alloy to study their effects on theelevated-temperature properties.Results show that TiB2nanoparticles were mainly distributed at the interdendritic grain boundarieswith a size range of20?80nm,which is confirmed by transmission electron microscopy(TEM)and X-ray diffraction(XRD).Therefore,the volume fraction of the dispersoid free zones is greatly reduced and the motion of grain boundaries and dislocations isinhibited more effectively at elevated temperature.After peak precipitation heat treatment,the yield strengths in the alloy with3%TiB2addition at room temperature and300°C were increased by20%and13%respectively,while the minimum creep rate at300°Cwas reduced to only1/5of the base alloy free of TiB2,exhibiting a considerable improvement of elevated-temperature properties inAl?Mn?Mg alloys.
文摘The microstructures of five Al Mn Mg alloys with different Mn, Si and Fe contents were investigated in as cast and homogenized states. The influences of chemical composition and homogenizing process on the microstructure were studied. The results show that the morphology of the primary second particles are not influenced by the variation of Mn, Si and Fe level, and the amount of the primary α phase, the α precipitates and Mg 2Si phase are enhanced by the addition of Si; The average size of primary intermetallic particles reduces and the volume fraction of them decreases slightly with the increase in homogenization temperature and time; However, the volume fraction of primary secondary particles is increased by adding more Mn, Si and Fe elements in alloys. Moreover, a new MgSiCu rich eutectic in the as cast ingot has been found.
基金Science and Technology Plan Project of Inner Mongolia(201802029)Major Science and Technology Projects of Inner Mongolia Autonomous Region(zdzx2018031)Graduate Research Innovation Project of Inner Mongolia Autonomous Region(S20210180Z)。
