Processing of 2198 Al-Li alloy: melting, rolling and heat treatment

Abstract:

Al-Li alloy is widely used in the aerospace field, due to its high specific strength and high specific modulus. The processing of 2198 alloy is investigated. 2198 alloy sheet with excellent mechanical properties is successfully manufactured. It will help the industrial production of 2198 Al-Li alloy. The ingot is melted and cast in vacuum induction melting (VIM) furnace. During the followed homogenization the as-cast microstructure can be completely vanished. The ingot is rolled to sheet with 2mm thickness, via multi-pass hot-rolling. Then, the solution, water quenching, pre-deformation, naturally aging and artificial aging are respectively carried out. The tensile strength of final 2198 Al-Li alloy sheet in the rolling direction is 486MPa. The precipitate T1 generated in the artificial aging can not only increase the strength obviously, but also decrease the anisotropy of 2198 Al-Li alloy sheet.