2198铝锂合金后续热处理制度及对织构影响的研究

通过力学性能和组织观察研究了2198新型铝锂合金的后续固溶时效热处理制度,并通过XRD衍射仪对原始板材和热处理之后的板材进行织构测算。对比分析表明：2198铝锂合金最佳固溶制度选为500℃×1 h小时,最佳时效制度定为175℃×20小时。经过重新固溶时效后,材料组织形貌、力学性能基本保持不变而延伸率变化小于3%。原始板材织构主要存在着较强的{-110}〈-1-12〉组分以及{001}〈0-10〉,{-3311}〈-1-10〉和{-5512}〈3-95〉组分,但经过重新固溶时效之后,主要织构变为{-110}〈-1-12〉,{-3313}〈-1-10〉和{-112}〈1-11〉组分,呈明显弱化趋势。从而改善此合金趋于各向同性条件下的抗疲劳性能与耐蚀性能。

Study on the post-heat treatment schedule and its effect on texture of 2198 aluminum lithium alloy

Based on mechanical properties and microstructure observed,the aging treatment of 2198 new aluminum-lithium alloy is investigated.Then,the texture of the original plate and that of the post-treated plate are analyzed by x-ray diffraction to obtain the variation.The results show that the optimal solid solution temperature and holding time for 2198 alloy are selected as 500 ℃×1 hour,and the best aging schedule is 175 ℃×20 h.Metallographic morphology of the alloy and its mechanical properties remain unchanged basically,and the variation of plastic elongation is less than 3% after the post-heat treatment schedule.The texture components in the original sheet are dominated by the strong {-110}-1-12,{001}0-10,{-3311}-1-10 and {-5512}3-95.However,the texture components change into {-110}-1-12,{-3313}-1-10 and {-112}1-11 during the re-treating process,which presents significant weakening tendency.Consequently,such a technique would improve the anti-fatigue properties and corrosion resistance under the condition of a better isotropy for this alloy.