Effect of cold rolling pre-deformation on microstructure and properties of V-1469 Al-Li alloy

Abstract

In order to provide a detailed reference for the processing of high-performance Al-Li alloy, the effects of cold rolling pre-deformation on the microstructure and properties of V-1469 Al-Li alloy were investigated by Vickers hardness, tensile measurement, intergranular corrosion, electrochemical technique and electron microscopy. The results show that the mechanical properties of V-1469 Al-Li alloy can be improved by cold rolling pre-deformation treatment. When a 10% deformation was applied, the tensile strength and yield strength reached 600 MPa and 560 MPa, respectively, and the elongation remained above 7%. Moreover, cold rolling pre-deformation treatment can effectively improve the corrosion properties of V-1469 Al-Li alloy. With the increase of pre-deformation, the maximum corrosion depth and corrosion degree are decreased. In addition, with the increase of cold rolling pre-deformation, the microstructure observation shows that the precipitation of θ’ (Al2Cu) phase is inhibited, while the main hardening-phase of T1 (Al2CuLi) phase disperses homogeneously in the grain. Besides, the volume fraction of T1 phases on the stacking fault (grain boundary and sub-grain boundary) decreases and its precipitating pattern changes from continuous precipitation to discontinuous precipitation, which causes the width of the precipitate free zone (PFZ) to gradually decrease.

Keywords

• V-1469 Al-Li alloy
• Cold rolling pre-deformation
• Microstructure
• Mechanical properties
• Corrosion properties