Investigation of anisotropy and structure variation of spray-formed 2195 Al-Li alloy via final temperature-controlled rolling and cold rolling

Abstract

The mechanical property anisotropy is one of the critical factors of limiting extensive application of the Al-Li alloy, which is mainly influenced by the textures, grain morphology and distribution of the aging precipitates. Through the plastic deformation process, the anisotropy can be weakened by regulating the grain structure. In this work, the final temperature-controlled rolling and cold rolling were carried out to investigate the grain structure variation and its effect on the mechanical property anisotropy of the spray-formed 2195 Al-Li alloy. The results show that the yield strength is improved but the anisotropy in the mechanical properties deteriorates as the final rolling temperature is elevated from 200 ℃ to 300 ℃. This is owed to the fibrous structures and a great number of deformation textures formed in the continuous static recrystallization process. Compared with the samples through final temperature-controlled rolling, the aged sample through cold rolling possesses higher yield strength and relatively weaker anisotropy due to the fine equiaxed grain structure. In addition, intense Brass and S textures existing in the plates are proven that can result in the heterogeneous distribution of the T1 phase and the anisotropic equivalent slip system number values along the longitudinal and transverse directions, which both contribute to the strong anisotropy. To facilitate the analysis of the effect of the textures on the mechanical properties and anisotropy, the equivalent Schmid factor and slip system number were also calculated and discussed. This study looks forward to providing reliable theoretical support for the practical application of spray-formed Al-Li alloys.