Effect of elastic strain energy on the core-shell structures of the precipitates in Al-Sc-Er alloys

• 作 者: 陈思成 李长荣 连广丽 郭翠萍 杜振民
• 机 构: School of Materials Science and Engineering,University of Science and Technology Beijing,
• 出 处: Journal of Rare Earths
• 发表日期: 2012年12期
• 关键词: precipitate partitioning overcome interfacial dispersed modulus expensive ultraf

The effect of the elastic strain energy on the core-shell structures was studied in an Al-0.06Sc-0.02Er (at.%) alloy. A theoretical model for the calculation of the elastic strain energy caused by core-shell precipitates, which is applicable to materials with weak elastic ani-sotropy, was adopted. It was demonstrated that the partitioning of Er to the precipitate core did not reduce the elastic strain energy as expected in the previous study. The resistance due to the elastic strain energy to form an Al3(Sc0.36Er0.64)-Al3(Sc0.8Er0.2) core-shell precipitate was quite small, and could be easily overcome by the decrease of the total interfacial energy, which was consistent with the previous experimental re-sults. On the other hand, the resistance due to the elastic strain energy to form an Al3Er-Al3Sc core-shell precipitate was much larger than that to form an Al3(Sc0.36Er0.64)-Al3(Sc0.8Er0.2) core-shell precipitate, thus the partitioning of all the Er atoms to the core was strongly hindered by the elastic strain energy and was not observed in the experiment of the previous study.)

The effect of the elastic strain energy on the core-shell structures was studied in an Al-0.06Sc-0.02Er (at.%) Alloy. A theoretical model for the calculation of the elastic strain energy caused by core-shell precipitates, which is applicable to materials with weak elastic ani-sotropy, was adopted. It was demonstrated that the partitioning of Er to the precipitate steel did not reduce the elastic strain energy as expected in the previous study. The resistance due to the elastic strain energy to form an Al3 (Sc0.36Er0.64) -Al3 (Sc0.8Er0.2) core-shell precipitate was quite small, and could be easily overcome by the decrease of the total interfacial energy, which was consistent with the previous experimental re-sults On the other hand, the resistance due to the elastic strain energy to form an Al3Er-Al3Sc core-shell precipitate was much larger than that to form an Al3 (Sc0.36Er0.64) -Al3 (Sc0.8Er0.2) core -shell precipitate, thus the partitioning of all the Er atoms to the core was strongly hinde red by the elastic strain energy and was not observed in the experiment of the previous study.)