摘要
It is generally considered that the Al3Sc nanoprecipitates are highly thermal stable,mainly due to quite slow Sc diffusion in theα-Al matrix.In this paper,we demonstrate in an Al-Cu-Sc alloy that the Cu atoms have dual effect on the coarsening of Al3Sc nanoprecipitates.On the one hand,the Cu atoms with high diffusivity tend to accelerate the Al3Sc coarsening,which results from the Cu-promoted Sc diffusion.On the other hand,some Cu atoms will segregate at the Al3Sc/matrix interface,which further stabilizes the Al3Sc nanoprecipitates by reducing the interfacial energy.Competition between these two effects is tailored by temperature,which rationalizes the experimental findings that the coarsening kinetics of Al3Sc nanoprecipitate is greatly boosted at 300℃-overaging while significantly suppressed at 400℃-overaging.
It is generally considered that the Al3Sc nanoprecipitates are highly thermal stable, mainly due to quite slow Sc diffusion in the α-Al matrix. In this paper, we demonstrate in an Al-Cu-Sc alloy that the Cu atoms have dual effect on the coarsening of Al3Sc nanoprecipitates. On the one hand, the Cu atoms with high diffusivity tend to accelerate the Al3Sc coarsening, which results from the Cu-promoted Sc diffusion.On the other hand, some Cu atoms will segregate at the Al3Sc/matrix interface, which further stabilizes the Al3Sc nanoprecipitates by reducing the interfacial energy. Competition between these two effects is tailored by temperature, which rationalizes the experimental findings that the coarsening kinetics of Al3Sc nanoprecipitate is greatly boosted at 300℃-overaging while significantly suppressed at 400℃-overaging.
基金
financially supported by the National Natural Science Foundation of China(Nos.51621063,51625103,51722104,51790482,51761135031 and 51871033)
the National Key Research and Development Program of China(No.2016YFB0700403)
the 111 Project of China(No.BP2018008)
supported by the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies.
作者简介
Corresponding author:J.Y.Zhang,E-mail addresses:jinyuzhang1002@mail.xjtu.edu.cn;Corresponding author:G.Liu,E-mail addresses:lgsammer@mail.xjtu.edu.cn;Corresponding author:J.Sun,E-mail addresses:junsun@mail.xjtu.edu.cn
