Isothermal sections at room temperature and 450°C for Al-rich (Al+0.15at%V)-Mg-Zn system have been determined by X-ray diffraction, microscopic observation and DTA methods. Comparing with Al-Mg-Zn system the α-p...Isothermal sections at room temperature and 450°C for Al-rich (Al+0.15at%V)-Mg-Zn system have been determined by X-ray diffraction, microscopic observation and DTA methods. Comparing with Al-Mg-Zn system the α-phase region in isothermal sections at room temperature and 450°C for the system with 0.15at%V is slightly narrowed and expanded respectively. The solubility limits of Zn and Mg in α-Al have been found to be 3.3at% (7.6wt%) and 5.5at%(5.0wt%) respectively at room temperature, and 6.0at% (13.4wt%) and 11.0at% (10.0wt%) at 450°C. The τ phase in this system is a ternary intermetallic compound, which undergoes an allotropic transformation at about 427°C.展开更多
The corrosion evolution of 2024-T351 and 7075-T651 aluminum alloys in the thin electrolyte layer(TEL)and wet-dry alternating cycle(WDAC)environment is studied in this work.The results show that in the TEL environment,...The corrosion evolution of 2024-T351 and 7075-T651 aluminum alloys in the thin electrolyte layer(TEL)and wet-dry alternating cycle(WDAC)environment is studied in this work.The results show that in the TEL environment,the competitive effect between H+that accelerates corrosion reactions and deposition of aluminum sulfate that impedes corrosion attacks exists during the corrosion exposure.The difference is that with increasing HSO_(3)^(-),subsurface intergranular corrosion on 2024-T351 is promoted to form exfoliation corrosion eventually and the degree of exfoliation corrosion begins to decrease because the blocking effect of aluminum sulfate exceeds the expediting effect of H+.For 7075-T651,the corrosion area and the corrosion diameter decrease gradually,which is attributed to the HSO_(3)^(-)-enhanced deposition of corrosion products and their blocking effect.In the WDAC environment,the corrosion processes of 2024-T351 and 7075-T651 are the acidic dissolution of the matrix during the soaking phase.When the HSO_(3)^(-)concentration is high enough(0.1 M),the inhibiting effect of aluminum sulfate becomes the dominant factor.展开更多
文摘Isothermal sections at room temperature and 450°C for Al-rich (Al+0.15at%V)-Mg-Zn system have been determined by X-ray diffraction, microscopic observation and DTA methods. Comparing with Al-Mg-Zn system the α-phase region in isothermal sections at room temperature and 450°C for the system with 0.15at%V is slightly narrowed and expanded respectively. The solubility limits of Zn and Mg in α-Al have been found to be 3.3at% (7.6wt%) and 5.5at%(5.0wt%) respectively at room temperature, and 6.0at% (13.4wt%) and 11.0at% (10.0wt%) at 450°C. The τ phase in this system is a ternary intermetallic compound, which undergoes an allotropic transformation at about 427°C.
基金The authors wish to acknowledge the financial support of the Natural Science Foundation of China(No.51931008)the Ministry of Industry and Information Technology Project(No.MJ-2017-J-99),and the Shandong Provincial Key R&D plan(No.2019GHY112050).
文摘The corrosion evolution of 2024-T351 and 7075-T651 aluminum alloys in the thin electrolyte layer(TEL)and wet-dry alternating cycle(WDAC)environment is studied in this work.The results show that in the TEL environment,the competitive effect between H+that accelerates corrosion reactions and deposition of aluminum sulfate that impedes corrosion attacks exists during the corrosion exposure.The difference is that with increasing HSO_(3)^(-),subsurface intergranular corrosion on 2024-T351 is promoted to form exfoliation corrosion eventually and the degree of exfoliation corrosion begins to decrease because the blocking effect of aluminum sulfate exceeds the expediting effect of H+.For 7075-T651,the corrosion area and the corrosion diameter decrease gradually,which is attributed to the HSO_(3)^(-)-enhanced deposition of corrosion products and their blocking effect.In the WDAC environment,the corrosion processes of 2024-T351 and 7075-T651 are the acidic dissolution of the matrix during the soaking phase.When the HSO_(3)^(-)concentration is high enough(0.1 M),the inhibiting effect of aluminum sulfate becomes the dominant factor.
