Investigation On Texture And Anisotropy Of The 2198 Aluminum-Lithium Alloy

2198 Al-Li alloy has been developing as a new structural material for aerospace application, which could reduce 3% density and increase 6% elastic modulus after adding 1 wt.% Li. 2198 Al-Li alloy was introduced to lower content of Copper contrasting to the earlier 2195 Al-Li alloy so as to reduce weight and significantly increase elongation.This thesis had taken 2198 Aluminum-Lithium alloy as investigating object, the best post-heat treatment schedule after analyzing the result of the aging treatment experiment, and revealing the texture evolution after cold rolling and hot rolling. The results are expected to providing reference in processing and manufacturing of 2198 Al-Li alloy.The results have shown that the original plate has strong {110}<112> B texture component and {123}<634> S texture component as well as good static mechanical properties in which tensile strength reachs 518MPa and the elongation gets to 14.9%Through the new solid solution and aging, the tensile strength reduce to 501MPa and the elongation determined as 13.8%. The performance in twin-stage heat treatment can not contribute apparently to the diversification compared with one-stage aging. Finally, the best post-heat treatment schedule was formulated at 500°C/ 1h + 135℃/18h and 175℃/20h.The strong texture component transformation in plate can not occur after cold-rolled which is still dominated by B and S components. Yet this convention could be broken after changing the rolling direction perpendicular to the primary direction. However, this tendency returns when the deformation ratio increases up to 70%.After hot rolling along the original RD direction at 415℃, the plate maintains the same original sheet texture components, while through 475℃hot rolling along the original rolling direction, this will render cubic and rotate cube texture components so as to occur recrystallization in Al-Li alloy plate. The effect of 415℃and 475℃cross hot-rolling perpendicular to the original direction on the texture components is basically the same, Recrystallization texture and deformation texture exist at the same time.