(1. Key Laboratory of Nonferrous Metal Materials Science and Engineering of Ministry of Education, School of Materials Science and Engineering, Central South University, Changsha 410083, China) (2. Southwest Aluminum (Group) Co., Ltd., Chongqing 401326, China)
Al-Li alloys are ideal aerospace materials due to their properties such as low density, high elastic modulus, high specific stiffness and strength, low fatigue crack propagation rate, good property at high and cryogenic temperatures. The research on novel Al-Li alloy materials attracted great attention all over the world, and new Al-Li alloy brands have been registered constantly. This paper introduces the main aging precipitates in Al-Li alloys, and summarizes the correlation between aging precipitates and mechanical properties, corrosion properties and fatigue crack propagation rate of Al-Li alloys. Combined with the influence of alloying elements and microalloying elements on the aging precipitates, the development of high strength and super-high strength Al-Li alloys, corrosion resistant Al-Li alloys, damage resistant Al-Li alloys and high hardenability Al-Li alloys is introduced. The shortcomings of domestic development of novel Al-Li alloys are summarized, and some development directions on Al-Li alloys in the future are proposed.